PHYSICAL REVIEW C 98, 024908 (2018)
Measu emen o je agmen a ion in Pb+Pb and pp collisions a √sNN =5.02 TeV
wi h he ATLAS de ec o
M. Aaboud e al.∗
(ATLAS Collabo a ion)
(Recei ed 16 May 2018; published 16 Augus 2018)
This pape p esen s a measu emen o je agmen a ion unc ions in 0.49 nb−1o Pb+Pb collisions and 25 pb−1
o pp collisions a √sNN =5.02 TeV collec ed in 2015 wi h he ATLAS de ec o a he LHC. These measu emen s
p o ideinsigh in o heje quenchingp ocess in he qua k-gluonplasma c ea edin hea e ma h o ul a ela i is ic
collisions be ween wo nuclei. The modi ica ions o he je agmen a ion unc ions a e quan i ied by di iding he
measu emen s in Pb+Pb collisions by baseline measu emen s in pp collisions. This a io is s udied as a unc ion
o he ans e se momen um o he je , he je apidi y, and he cen ali y o he collision. In bo h collision sys ems,
he je agmen a ion unc ions a e measu ed o je s wi h ans e se momen um be ween 126 and 398 GeV and
wi h an absolu e alue o je apidi y less han 2.1. An enhancemen o pa icles ca ying a small ac ion o he
je momen um is obse ed, which inc eases wi h cen ali y and wi h inc easing je ans e se momen um. Yields
o pa icles ca ying a e y la ge ac ion o he je momen um a e also obse ed o be enhanced. Be ween hese
wo enhancemen s o he agmen a ion unc ions a supp ession o pa icles ca ying an in e media e ac ion o
he je momen um is obse ed in Pb+Pb collisions. A small dependence o he modi ica ions on je apidi y is
obse ed.
DOI: 10.1103/PhysRe C.98.024908
I. INTRODUCTION
Ul a ela i is ic nuclea collisions a he La ge Had on Col-
lide (LHC) p oduce ho dense ma e called he qua k-gluon
plasma (QGP); ecen e iews can be ound in Re s. [1,2].
Ha d-sca e ing p ocesses occu ing in hese collisions p o-
duceje swhich a e seandin e ac wi h heQGP.Thes udyo
modi ica ions o je a es and p ope ies in hea y-ion collisions
compa ed o pp collisions p o ides in o ma ion abou he
p ope ies o he QGP.
The a es o je p oduc ion a e obse ed o be educed
by app oxima ely a ac o o 2 in lead-lead (Pb+Pb) colli-
sions a LHC ene gies compa ed o expec a ions om he je
p oduc ion c oss sec ions measu ed in pp in e ac ions scaled
by he nuclea o e lap unc ion o Pb+Pb collisions [3–5].
Simila ly, back- o-back dije [6–8] and pho on-je pai s [9]a e
obse ed o ha e unbalanced ans e se momen um in Pb+Pb
collisions compa ed o pp collisions. Rela ed phenomena
we e i s obse ed a he Rela i is ic Hea y Ion Collide
whe e he measu emen s we e made wi h had ons a he han
econs uc edje s[10–12].Theseobse a ionsimply ha some
o he ene gy o he pa on showe ing p ocess is ans e ed
ou side o he je h ough i s in e ac ion wi h he QGP. This
has been e med “je quenching.”
∗Full au ho lis gi en a he end o he a icle.
Published by he Ame ican Physical Socie y unde he e ms o he
C ea i e Commons A ibu ion 4.0 In e na ional license. Fu he
dis ibu ion o his wo k mus main ain a ibu ion o he au ho (s)
and he published a icle’s i le, jou nal ci a ion, and DOI.
The dis ibu ion o pa icles wi hin he je a e a ec ed by
his mechanism o ene gy loss. Se e al ela ed obse ables
sensi i e o he p ope ies o he medium can be cons uc ed.
Measu emen s o he je shape [13] and he agmen a ion
unc ions we e made in 2.76 TeV Pb+Pb collisions [14–16].
In Re . [16], je agmen a ion unc ions a e measu ed as a
unc ion o bo h he cha ged-pa icle ans e se momen um
pTand he cha ged-pa icle longi udinal momen um ac ion
ela i e o he je ,
z≡pTcos R/p
je
T.(1)
The agmen a ion unc ions a e de ined as
D(z)≡1
Nje
dnch
dz ,
and
D(pT)≡1
Nje
dnch
dpT
,
whe e pje
Tis he ans e se momen um o he je , nch is he
numbe o cha ged pa icles in he je , Nje is he numbe o
je s unde conside a ion, and R=(η)2+(φ)2wi h
ηand φde ined as he di e ences be ween he je axis and
he cha ged-pa icle di ec ion in pseudo apidi y and azimu h,1
1ATLAS uses a igh -handed coo dina e sys em wi h i s o igin a he
nominal in e ac ion poin (IP) in he cen e o he de ec o and he z
axis along he beam pipe. The xaxis poin s om he IP o he cen e o
he LHC ing, and he yaxis poin s upwa d. Cylind ical coo dina es
( , φ) a e used in he ans e se plane, φbeing he azimu hal angle
2469-9985/2018/98(2)/024908(34) 024908-1 ©2018 CERN, o he ATLAS Collabo a ion
M. AABOUD e al. PHYSICAL REVIEW C 98, 024908 (2018)
espec i ely. In o de o quan i y di e ences be ween Pb+Pb
and pp collisions a he same collision ene gy, he a ios o he
agmen a ion unc ions a e measu ed:
RD(z)≡D(z)PbPb
D(z)pp
,
and
RD(pT)≡D(pT)PbPb
D(pT)pp
.
Rela i e o je s in pp collisions, i was ound in Re . [16]
ha je s in Pb+Pb collisions ha e an excess o pa icles wi h
ans e se momen um below 4 GeV and an excess o pa icles
ca ying a la ge ac ion o he je ans e se momen um. A
in e media e cha ged-pa icle pT, he e is a supp ession o
he cha ged-pa icle yield. A he same ime, an excess o
low-pTpa icles is obse ed o pa icles in a wide egion
a ound he je cone [17,18]. These obse a ions may indica e
ha he ene gy los by je s h ough he je quenching p ocess
is being ans e ed o so pa icles wi hin and a ound he
je [19,20]; measu emen s o hese so pa icles ha e he
po en ial o cons ain he models desc ibing such p ocesses. A
possible explana ion o he enhancemen o pa icles ca ying
a la ge ac ion o he je momen um is ha i is ela ed
o he gluon-ini ia ed je s losing mo e ene gy han qua k-
ini ia ed je s. This leads o a highe qua k-je ac ion in Pb+Pb
collisions han in pp collisions. The change in la o compo-
si ion combined wi h he di e en shapes o he qua k and
gluon agmen a ion unc ions [21] hen lead o he obse ed
excess.
P o on-nucleus collisions, which do no gene a e a la ge
amoun o QGP, a e used o di e en ia e be ween ini ial- and
inal-s a e e ec s due o he QGP o med in Pb+Pb collisions.
F agmen a ion unc ions in p+Pb collisions show no e idence
o modi ica ion when compa ed wi h hose in pp collisions
[22]. Thus, any modi ica ions obse ed in Pb+Pb collisions
can be a ibu ed o he p esence o he QGP a he han o
e ec s a ising om he p esence o he la ge nucleus.
The apidi y dependence o je obse ables in Pb+Pb
collisions is o g ea in e es , in pa because a ixed pje
T he
ac ion o qua k je s inc eases wi h inc easing |yje |(see, o
example,Re s.[21,23]).Thismakes he apidi ydependenceo
je obse ablespo en iallysensi i e o hedi e en in e ac ions
o qua ks and gluons wi h he QGP. P e ious measu emen s
o he apidi y dependence o je agmen a ion unc ions
a √sNN =2.76 TeV in Pb+Pb collisions ound a apidi y
dependence o he agmen a ion unc ion modi ica ion wi h
limi ed signi icance [16].
In his pape , he agmen a ion unc ions and he RD(z)
and RD(pT) a ios a e measu ed in Pb+Pb and pp collisions
a 5.02 TeV using 0.49 nb−1o Pb+Pb collisions and 25 pb−1
o pp collisions collec ed in 2015. Je s a e measu ed o e a
a ound he beam pipe. The pseudo apidi y is de ined in e ms o he
pola angle θas η=−ln an(θ/2). The apidi y is de ined as y=
0.5ln[(E+pz)/(E−pz)] whe e Eand pza e he ene gy and he
componen o he momen um along he beam di ec ion.
apidi y angeo |yje |<2.1using hean i-k econs uc ional-
go i hm[24]wi h adiuspa ame e R=0.4.Themeasu emen
is p esen ed in in e als o pje
T,yje , and collision cen ali y.
These da a ex end he p e ious s udies a √sNN =2.76 TeV in
wo ways. Fi s , an inc ease in he peak ene gy densi y o he
medium is expec ed. Second, he Pb+Pb in eg a ed luminosi y
in he cu en da ase is 3.5 imes he in eg a ed luminosi y
a ailable a 2.76 TeV, and he inc ease in he collision ene gy
also inc eases he je c oss sec ions. These wo ac o s allow a
measu emen o he dependence o je agmen a ion unc ions
on he ans e se momen um o he je o e a wide ange han
was p e iously possible.
II. EXPERIMENTAL SETUP
The measu emen s p esen ed in his pape we e pe o med
using he ATLAS inne de ec o , calo ime e , igge , and da a
acquisi ion sys ems [25]. The calo ime e sys em consis s o a
sampling liquid a gon (LA ) elec omagne ic (EM) calo ime-
e co e ing |η|<3.2, a s eel/scin illa o sampling had onic
calo ime e co e ing |η|<1.7, LA had onic calo ime e s
co e ing 1.5<|η|<3.2, and wo LA o wa d calo ime e s
(FCal) co e ing 3.1<|η|<4.9[25]. The EM calo ime e s
a e segmen ed longi udinally in showe dep h in o h ee laye s
wi hanaddi ional p esample laye .Theyha esegmen a ion in
φand η ha a ies wi h laye and pseudo apidi y. The had onic
calo ime e s ha e h ee sampling laye s longi udinal in showe
dep h.
The inne de ec o measu es cha ged pa icles wi hin he
pseudo apidi y in e al |η|<2.5 using a combina ion o sil-
icon pixel de ec o s, silicon mic os ip de ec o s (SCTs), and
a s aw- ube ansi ion adia ion acke (TRT), all imme sed
ina2Taxialmagne ic ield [25]. Each o he h ee de-
ec o s is composed o a ba el and wo symme ic endcap
sec ions. The pixel de ec o is composed o ou laye s: he
“inse ableB laye ” [26,27] and h ee laye s wi h apixel size o
50 μm×400 μm. The SCT ba el sec ion con ains ou laye s
o modules wi h 80 μm pi ch senso s on bo h sides and each
endcap consis s o nine laye s o double-sided modules wi h
adial s ips ha ing a mean pi ch o 80 μm. The wo sides o
eachSCTlaye inbo h heba eland heendcapsha ea ela i e
s e eo angle o 40 m ad. The TRT con ains up o 73 (160)
laye s o s agge ed s aws in e lea ed wi h ibe s in he ba el
(endcap).
The ze o-deg ee calo ime e s (ZDCs) a e loca ed sym-
me ically a z=±140 m and co e |η|>8.3. They a e
cons uc ed om ungs en abso be pla es and ˇ
Ce enko ligh
is ansmi ed ia qua z ibe s. In Pb+Pb collisions he ZDCs
p ima ily measu e “spec a o ” neu ons, i.e., neu ons ha do
no in e ac had onically when he inciden nuclei collide. A
ZDCcoincidence igge is implemen ed by equi ing hepulse
heigh om each ZDC o be abo e a h eshold se o accep he
single-neu on peak.
A wo-le el igge sys em is used o selec he Pb+Pb and
pp collisions. The i s igge le el (L1) is ha dwa e-based
and implemen ed wi h cus om elec onics. The second le el
is he so wa e-based high-le el igge (HLT) and is used o
u he educe he accep ed e en a e. Minimum-bias Pb+Pb
e en s a e eco ded using a igge de ined by he logical OR
024908-2
MEASUREMENT OF JET FRAGMENTATION IN Pb+Pb AND … PHYSICAL REVIEW C 98, 024908 (2018)
o a L1 o al ene gy igge and he ZDC coincidence igge .
The o al ene gy igge equi ed he o al ans e se ene gy
measu ed in he calo ime e sys em o be g ea e han 50 GeV
in Pb+Pb collisions. Je e en s a e selec ed by he HLT, a e
equi ing he iden i ica ion o a je by he L1 je igge in
pp collisions o he o al ene gy igge wi h a h eshold o
50 GeV in Pb+Pb collisions. The L1 je igge u ilized in
pp collisions equi ed a je wi h ans e se momen um g ea e
han 20 GeV. The HLT je igge used a je econs uc ion
algo i hm simila o ha used in he o line analysis ( he o line
je econs uc ion is discussed in Sec. IV). I selec ed e en s
con aining je s wi h ans e se ene gy o a leas 75 GeV in
Pb+Pb collisions and a leas 85 GeV in pp collisions. In pp
collisions, he 85 GeV h eshold je igge sampled he ull
deli e ed luminosi y. The 75 GeV h eshold je igge used in
Pb+Pb collisions was p escaled2in a small pa o he Pb+Pb
da a- aking pe iod; howe e , he igge sampled mo e han
99% o he o al in eg a ed luminosi y. The measu emen is
pe o med in he je ans e se momen um egion whe e he
igge s a e ully e icien .
III. DATA SETS AND EVENT SELECTION
The Pb+Pb and pp da a used in his analysis we e eco ded
in2015.The da asamplesconsis o 25 pb−1o √s=5.02TeV
pp da a and 0.49 nb−1o √sNN =5.02 TeV Pb+Pb da a.
In Pb+Pb and pp collisions, e en s a e equi ed o ha e a
econs uc ed e ex wi hin 150 mm o he nominal in e ac ion
poin along he beam axis. Only e en s aken du ing s able
beam condi ions and sa is ying de ec o and da a-quali y e-
qui emen s, which include he calo ime e s and inne acking
de ec o s being in nominal ope a ion, a e conside ed.
In Pb+Pb collisions, he e en cen ali y e lec s he o e lap
a ea o he wo colliding nuclei and is cha ac e ized by EFCal
T,
he o al ans e se ene gy deposi ed in he FCal [28]. The
cen ali y in e als used in his analysis a e de ined acco ding
o successi e pe cen iles o he EFCal
Tdis ibu ion ob ained
om minimum-bias igge ed Pb+Pb e en s o de ed om he
mos cen al (highes EFCal
T) o he mos pe iphe al collisions
(lowes EFCal
T): 0–10%, 10–20%, 20–30%, 30–40%, 40–
60%, 60–80%.
In addi ion o he je - igge ed sample, a sepa a e Pb+Pb
da a sample was eco ded wi h he minimum-bias igge and
wo o al ans e se-ene gy igge s equi ing 1.5 and 6.5 TeV
o enhance he a e o mo e cen al Pb+Pb e en s. This da a
sample is used o p oduce a Pb+Pb Mon e Ca lo (MC) e en s
wi h condi ions ha ma ch hose egis e ed while he da a we e
eco ded.
The pe o mance o he de ec o and o he analysis
p ocedu e in Pb+Pb collisions is e alua ed using 1.8×107
5.02 TeV MC e en s. These we e p oduced om minimum-
bias Pb+Pb da a e en s o e laid wi h ha d-sca e ing dije
pp e en s gene a ed wi h POWHEG+PYTHIA8[29,30]using
a se o uned pa ame e s called he A14 une [31] and he
2The p escale indica es which ac ion o e en s ha passed he
igge selec ion was selec ed o eco ding by he da a acquisi ion
sys em.
NNPDF23LO pa on dis ibu ion unc ion (PDF) se [32]. The
de ec o esponse was simula ed using GEANT4[33,34] and
he simula ed hi s we e combined wi h hose om he da a
e en . A weigh is assigned o each MC e en such ha he
e en sample ob ained om he minimum-bias igge has he
same cen ali y dis ibu ion as he sample collec ed by he je
igge . A sepa a e sample o 1.8×107simula ed 5.02 TeV
PYTHIA8pp ha d-sca e ing e en s, gene a ed wi h he same
uneandPDFsas o hePb+PbMCsample,is used oe alua e
he pe o mance o measu ing agmen a ion unc ions in he
pp da a. The con ibu ion om addi ional collisions in he
same bunch c ossing is no included in he MC simula ion. A
sample o Pb+Pb e en s gene a ed wi h HIJING e sion 1.38b
[35] is also used o e alua e he pe o mance o he ack
econs uc ion.
IV. JET AND TRACK SELECTION
The je econs uc ion, unde lying e en (UE) de e mina-
ion, and sub ac ion p ocedu es closely ollow hose used by
ATLAS o je measu emen s in pp and Pb+Pb collisions a
√sNN =2.76 TeV [4]. The an i-k algo i hm is i s un in ou -
momen um ecombina ion mode, on η×φ=0.1×0.1
calo ime e owe s wi h he an i-k adius pa ame e R=0.2
and R=0.4. The ene gies in he owe s a e ob ained by sum-
ming he ene gies o calo ime e cells a he elec omagne ic
ene gy scale wi hin he owe bounda ies. Then, an i e a i e
p ocedu e is used o es ima e he η-dependen UE ans e se
ene gy densi y on an e en -by-e en basis using he ene gy
measu emen s in all calo ime e owe s in he e en while
excluding he egions popula ed by je s. The esul ing UE
ans e se ene gy densi y is modula ed aking in o accoun he
p esence o he azimu hal aniso opy o pa icle p oduc ion
[36]. The modula ion includes con ibu ions o he second-,
hi d-, and ou h-o de azimu hal aniso opy ha monics.
Highe -o de ha monics in oduce negligible a ia ion o he
econs uc ed je ene gy. The UE ans e se ene gy is sub-
ac ed om each calo ime e cell wi hin he owe s included
in he econs uc ed je , and he ou -momen um o he je is
upda ed acco dingly. Then, a je η- and pT-dependen co ec-
ion ac o o he pje
Tde i ed om he simula ion samples is
applied o co ec o he calo ime e ene gy esponse [37]. An
addi ional co ec ion based on in si u s udies o je s ecoiling
agains pho ons, Zbosons, and je s in o he egions o he
calo ime e is applied [38,39]. The same je econs uc ion
p ocedu e wi hou he azimu hal modula ion o he UE is also
applied o pp collisions.
Je s a e equi ed o ha e a apidi y wi hin |yje |<2.1 so ha
all R=0.4 je cones a e con ained wi hin he inne de ec o ’s
accep ance. To p e en neighbo ing je s om dis o ing he
measu emen o he agmen a ion unc ions,je sa e ejec edi
he e is ano he je wi h highe pje
Tanywhe e wi hin a dis ance
R<1.0. A co ec ion is applied o educe he e ec s o
he b oadening o he je di ec ion measu emen o R=0.4
je s due o he UE. The co ec ion uses je s econs uc ed
wi h a smalle dis ance pa ame e R=0.2 since hei angula
esolu ion e alua ed in MC s udies is ound o be less a ec ed
by he UE luc ua ions han ha o la ge -Rje s. The je
di ec ion is ede ined as ha o he closes R=0.2 je wi h
024908-3
M. AABOUD e al. PHYSICAL REVIEW C 98, 024908 (2018)
[GeV]
u h
T
p
1 10 2
10
T acking e iciency
0.7
0.75
0.8
0.85
0.9
0.95
1
ATLAS Simula ion
= 5.02 TeVs
pp
< 158 GeV
je
T
p126 GeV <
< 200 GeV
je
T
p158 GeV <
< 251 GeV
je
T
p200 GeV <
< 316 GeV
je
T
p251 GeV <
< 398 GeV
je
T
p316 GeV <
| < 0.3
je
y|
=0.4R
kan i-
[GeV]
u h
T
p
1 10 2
10
T acking e iciency
0.7
0.75
0.8
0.85
0.9
0.95
1
< 158 GeV
je
T
p0-10%, 126 GeV <
< 316 GeV
je
T
p0-10%, 251 GeV <
< 158 GeV
je
T
p60-80%, 126 GeV <
< 316 GeV
je
T
p60-80%, 251 GeV <
ATLAS Simula ion
= 5.02 TeV
NN
s Pb+Pb
| < 0.3
je
y|
=0.4R
kan i-
FIG. 1. T acking e iciency ε, smoo hed using a hi d-o de polynomial in ln(p u h
T) as a unc ion o p u h
Tin pp collisions in i e di e en
je -pTin e als (le ) and in Pb+Pb collisions ( igh ) in wo di e en je -pTin e als and o 0–10% and 60–80% cen ali y in e als. In bo h
plo s he e iciency is e alua ed o acks wi hin je s wi h |yje |<0.3.
pje
T>35 GeV and ma ching he o iginal je di ec ion wi hin
R=0.3o heR=0.4 je , when such a ma ching je is
ound. I no ma ching R=0.2 je is ound he axis emains
unchanged.
Cha ged-pa icle acks a e econs uc ed om hi s in he
inne de ec o using he ack econs uc ion algo i hm wi h
se ings op imized o he high hi densi y in hea y-ion colli-
sions [40]. T acks used in his analysis a e equi ed o ha e a
o al o a leas 9 (11) hi s in he silicon pixel and mic os ip
de ec o s o cha ged pa icles wi h pseudo apidi y |ηch|⩽
1.65(|ηch|>1.65). A leas one hi is equi ed in one o he wo
inne mos pixel laye s. I he ack ajec o y passed h ough
an ac i e module in he inne mos laye , hen a hi in his laye
is equi ed. Fu he mo e, a ack mus ha e no mo e han wo
holes in he Pixel and SCT de ec o s oge he , whe e a hole is
de ined by he absence o a hi p edic ed by he ack ajec o y.
All cha ged-pa icle acks used in his analysis a e equi ed
o ha e econs uc ed ans e se momen um pch
T>1GeV.In
o de osupp ess he con ibu ion om seconda y pa icles, he
dis ance o closes app oach o he ack o he p ima y e ex
in he ans e se plane is equi ed o be less han a alue which
a ies om 0.45 mm a pch
T=4GeV o0.2mma pch
T=20
GeV, and a ha poin he ack mus be less han 1.0 mm om
he p ima y e ex in he longi udinal di ec ion.
The e iciency, ε(p u h
T,p
je
T,yje ), o econs uc ing
cha ged pa icles wi hin je s in Pb+Pb and pp collisions
is e alua ed om he ma ching o econs uc ed acks o
gene a o -le elp ima ypa icles3usingMCsamplesdesc ibed
abo e. The ma ching is based on con ibu ions o gene a o -
le el pa icles o he hi s in he de ec o laye s. A econs uc ed
ack is ma ched o a gene a o -le el pa icle i i con ains
hi s p oduced p ima ily by his pa icle [34]. The e iciency
is e alua ed sepa a ely in ou |yje |in e als and each in e al
o econs uc ed pje
Tused in he measu emen . Fu he mo e,
he e iciency is e alua ed sepa a ely o each cen ali y in-
e al in he case o Pb+Pb collisions. The cha ged-pa icle
3P ima y pa icles a e de ined as pa icles wi h a mean li e ime
τ>0.3×10−10 s ei he di ec ly p oduced in pp in e ac ions o
om subsequen decays o pa icles wi h a sho e li e ime. All o he
pa icles a e conside ed o be seconda y.
econs uc ion e iciencies as a unc ion o he gene a o -le el
p ima y pa icle ans e se momen um, p u h
T,a eshownin
Fig. 1 o je s wi h |yje |<0.3inpp and Pb+Pb collisions. In
o de o emo e luc ua ions in he e iciency due o he limi ed
MC sample size, he p u h
Tdependence o he e iciencies is
pa ame ized and smoo hed using a hi d-o de polynomial in
ln(p u h
T) ha gi es a good desc ip ion o he e iciency in he
ull ange o p u h
T. The e iciencies shown in Fig. 1exhibi
only a modes a ia ion wi h p u h
T, cen ali y, and pje
T.Asmall
almos con inuousinc easeo hee iciencywi h heinc easing
p u h
Tis obse ed. The e iciency o e he 20–100 GeV p u h
T
ange is smalle o high pje
Tcompa ed o low pje
Tby abou
2% and 5% in pp and Pb+Pb collisions, espec i ely. This
beha io is a ibu ed o he highe p obabili y o lose acks in
he dense co e o high-pTje s han o lose acks ha a e mo e
isola ed [41]. The e iciency is lowe in mo e cen al Pb+Pb
collisions due o he highe hi densi y. The e iciency exhibi s
only a small a ia ion wi h yje in he egion |yje |<1.2, and
i dec eases by app oxima ely 10% in he mos o wa d yje
in e al.
The con ibu ion o econs uc ed acks which a e no be
ma ched o a gene a ed p ima y pa icle in he MC samples
o pp collision e en s p oduced wi hou da a o e lay, along
wi h he esidual con ibu ion o acks ma ched o seconda y
pa icles, a e oge he conside ed “ ake” acks. The ac ion
o ake acks is less han 2% o e he ull kinema ic ange
o his measu emen . A possible deg ada ion o he acking
pe o mance a high occupancy is checked in he sample o
Pb+Pb collision e en s simula ed wi h he HIJING MC. No
signi ican dependence o he a e o ake acks on cen ali y is
obse ed. The co ec ion o he ake con ibu ion is discussed
in Sec. V.
V. ANALYSIS PROCEDURE
The analysis p ocedu e closely ollows he one used in he
measu emen o je agmen a ion a √sNN =2.76 TeV [16].
Recons uc ed acks a e associa ed wi h a econs uc ed je i
hey all wi hin R=0.4 o he je axis and o each o hese
pa icles he longi udinal momen um ac ion zis calcula ed.
The measu ed ack yields, dnmeas
ch /dz o dnmeas
ch /dpch
T,a e
024908-4
MEASUREMENT OF JET FRAGMENTATION IN Pb+Pb AND … PHYSICAL REVIEW C 98, 024908 (2018)
FIG. 2. Ra io o he measu ed cha ged-pa icle dis ibu ions be o e and a e he sub ac ion o he UE and ake acks as a unc ion o pch
T
o pje
Tin he ange 126–158 GeV o 0–10% (le ), 30–40% (middle), and 60–80% ( igh ) cen ali y. The unce ain ies a e smalle han he
ma ke size in all cases o which he e is a signi ican UE.
cons uc ed as
dnmeas
ch
dz =
Nchz, yje ,p
je
T
z
and
dnmeas
ch
dpch
T=
Nchpch
T,yje ,p
je
T
pch
T
,
whe e he quan i ies Nch(z) and Nch(pch
T) ep esen he
numbe o associa ed acks wi hin he gi en zo pch
T ange,
espec i ely co ec ed o he ack econs uc ion e iciency.
The e iciency co ec ion is applied as a 1/ε(pch
T,p
je
T,yje )
weigh on a ack-by- ack basis, assuming pch
T=p u h
T. While
ha assump ion is no s ic ly alid, he e iciency a ies
su icien ly slowly wi h p u h
T ha he e o in oduced by his
assump ion is less han 1%.
T acks which a e no co ela ed wi h he je need o be
sub ac ed om he measu ed dis ibu ions; hese acks come
om bo h ake acks and he UE. In Pb+Pb collisions,
con ibu ions o he agmen a ion unc ions om he cha ged
pa icles o igina ing om he UE in Pb+Pb collisions a e
sub ac ed. This con ibu ion is e alua ed as a unc ion o
cha ge pa icle zo pch
T,yje ,pje
T, and he collision cen ali y.
Addi ionally, he measu ed ack yields in pp and Pb+Pb
collisions a e co ec ed o he p esence o ake acks.
The UE con ibu ion is de e mined o each measu ed je
usingag ido R=0.4 cones spanning he ull co e age o
he inne de ec o and ollowing he me hod in oduced in
Re . [14]. The me hod is applied o e en s con aining je s
included in he analysis. The cones ha e a ixed dis ance
be ween hei cen e s chosen such ha he inne de ec o
accep ance is uni o mly co e ed while a oiding o e laps.
z
2−
10 1−
10 1
)z(D /
sub
)z(D
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
, 0-10%
-1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
-1
= 5.02 TeV, 25 pbs,pp
< 158 GeV
je
T
p126 <
ATLAS
|<2.1
je
y=0.4 je s, |R
kan i-
[GeV]
T
p
1 10
)
T
p(D /
sub
)
ch
T
p(D
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
, 0-10%
-1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
-1
= 5.02 TeV, 25 pbs,pp
< 158 GeV
je
T
p126 <
ATLAS
|<2.1
je
y=0.4 je s, |R
kan i-
z
2−
10 1−
10 1
)z(D /
sub
)z(D
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
, 0-10%
-1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
-1
= 5.02 TeV, 25 pbs,pp
< 316 GeV
je
T
p251 <
ATLAS
|<2.1
je
y=0.4 je s, |R
kan i-
[GeV]
T
p
1 10 2
10
)
T
p(D /
sub
)
ch
T
p(D
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
, 0-10%
-1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
-1
= 5.02 TeV, 25 pbs,pp
< 316 GeV
je
T
p251 <
ATLAS
|<2.1
je
y=0.4 je s, |R
kan i-
FIG. 3. Ra ios Dsub(z)/D(z)(le )andDsub(pch
T)/D(pT) ( igh ) o pp and 0–10% cen al Pb+Pb collisions o 126 <p
je
T<158 GeV
( op) and 251 <p
je
T<316 GeV (bo om) o |yje |<2.1. The e o ba s show he s a is ical unce ain ies and he boxes show he sys ema ic
unce ain ies in he un olding p ocedu e.
024908-5

M. AABOUD e al. PHYSICAL REVIEW C 98, 024908 (2018)
z
2−
10 1−
10 1
[%]
D(z)δ
20−
15−
10−
5−
0
5
10
15
20
25
JES
JER
Un olding
MC non-closu e
T acking
UE sub ac ion
To al
=0.4R
kan i-
|<2.1
je
y|
ATLAS
= 5.02 TeV
NN
s
-1
Pb+Pb 2015, 0.49 nb
< 158 GeV
je
T
p126 <
0-10%
z
2−
10 1−
10 1
[%]
D(z)δ
20−
15−
10−
5−
0
5
10
15
20
25
JES
JER
Un olding
MC non-closu e
T acking
To al
=0.4R
kan i-
|<2.1
je
y|
ATLAS
= 5.02 TeVs
-1
2015, 25 pbpp
< 158 GeV
je
T
p126 <
[GeV]
T
p
1 10
) [%]
T
p(Dδ
20−
15−
10−
5−
0
5
10
15
20
25
JES
JER
Un olding
MC non-closu e
T acking
UE sub ac ion
To al
=0.4R
kan i-
|<2.1
je
y|
ATLAS
= 5.02 TeV
NN
s
-1
Pb+Pb 2015, 0.49 nb
< 158 GeV
je
T
p126 <
0-10%
[GeV]
T
p
1 10
) [%]
T
p(Dδ
20−
15−
10−
5−
0
5
10
15
20
25
JES
JER
Un olding
MC non-closu e
T acking
To al
=0.4R
kan i-
|<2.1
je
y|
ATLAS
= 5.02 TeVs
-1
2015, 25 pbpp
< 158 GeV
je
T
p126 <
FIG. 4. Summa y o he sys ema ic unce ain ies o he D(z) ( op) and D(pT) (bo om) dis ibu ions in 0–10% cen al Pb+Pb collisions
(le ) and pp collisions ( igh ) o je s in he 126–158 GeV pje
Tin e al. The sys ema ic unce ain ies due o JES, JER, un olding, UE con ibu ion,
MC nonclosu e and acking a e shown along wi h he o al sys ema ic unce ain y om all sou ces.
Any cone ha ing a cha ged pa icle wi h pch
T>10 GeV o
o e lapping wi h a econs uc ed je wi h pje
T>90 GeV is
assumed o be associa ed wi h a ha d p ocess and is excluded
om he UE es ima ion o a oid biasing i . The pa ame e s
de ining he exclusion egions a e e alua ed in MC s udies
and a e subjec ed o a ia ions as pa o he es ima ion o
sys ema ic unce ain ies. The esul ing UE cha ged pa icle
yields, dnUE
ch /dz o dnUE
ch /dpch
T, a e e alua ed o e 1 <p
ch
T<
10 GeV acco ding o
dnUE
ch
dz =1
Ncone
1
εpch
T,ηch
Ncone
ch z,pje
T,yje 
zz=pch
Tcos R/pje
T
,
dnUE
ch
dpch
T=1
Ncone
1
εpch
T,η
ch
Ncone
ch pch
T,p
je
T,yje 
pch
T
.
He e Ncone is he numbe o backg ound cones used in he UE
de e mina ion o a gi en je , Ncone
ch ep esen s he numbe o
cha ged pa icles summed o e all backg ound cones, and R
ep esen s he dis ance be ween he cen e o a cone and he
di ec iono a gi encha gedpa icle. The e mε(pch
T,η
ch)is he
e iciency o econs uc ing cha ged pa icles, es ima ed as a
unc iono pch
Tandηch wi hou equi ing ack- o-je ma ching.
The es ima ed con ibu ion om he UE in each cone is
co ec ed o he di e ence in he a e age yield o UE cha ged
pa icles a a gi en pch
Tbe ween he ηposi ion o he cone and
ηposi ion o he je . This co ec ion is based on he cen ali y-,
pch
T-, and η-dependen dis ibu ion o cha ged-pa icle yields
in minimum-bias da a e en s. An addi ional co ec ion is
applied o he cha ged-pa icle UE es ima e o accoun o he
di e ence in he azimu hal pa icle densi y, due o ellip ic low,
be ween he φangle o he cone and he φangle o he je . This
u ilizes a cen ali y- and pch
T-dependen pa ame iza ion o he
measu ed ellip ic low coe icien s [36].
The UE con ibu ion is u he co ec ed o he co ela ion
be ween he ac ual UE cha ged pa icle yield unde nea h he
je and he je ene gy esolu ion [14]; in egions whe e he
UE has an upwa d luc ua ion, he je ene gy esolu ion is
wo se. The smea ing due o je ene gy esolu ion leads o a
ne mig a ion o je s om lowe pje
T o highe pje
T alues.
The e ec o he mig a ion causes he ac ual UE con ibu ion
unde nea h he je o be la ge han ha es ima ed om he
p ocedu e desc ibed abo e. This e ec is co ec ed o by
applying mul iplica i e co ec ion ac o s, depending on pch
To
z,yje ,pje
T, and collision cen ali y. The co ec ion is es ima ed
as a a io o he UE cha ged pa icle yield e alua ed by wo
di e en me hods using he Pb+Pb MC samples. The i s
es ima e uses he cone me hod discussed abo e. The second
me hod calcula es he UE con ibu ion in he da a o e lay
MC samples om acks, wi hin he a ea o a je , ha do no
ha e an associa ed gene a ed p ima y pa icle. The size o he
co ec ion is less han 2% a low zo pch
Twhe e he UE has he
la ges impac , and has only a small dependence on pje
T.
The con ibu ion om ake acks o he agmen a ion
unc ionsises ima ed om heMCsampleswi hou minimum-
bias in e ac ions o e laid. The ac ion o hese acks is ound
o be below 2% o he acks ha pass he selec ion in all ack
and je kinema ic egions in his analysis.
024908-6
MEASUREMENT OF JET FRAGMENTATION IN Pb+Pb AND … PHYSICAL REVIEW C 98, 024908 (2018)
z
2−
10 1−
10 1
[%]
D(z)
Rδ
20−
15−
10−
5−
0
5
10
15
20
25
JES
JER
Un olding
MC non-closu e
T acking
UE sub ac ion
To al
=0.4R
kan i-
|<2.1
je
y|
ATLAS -1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
-1
= 5.02 TeV, 25 pbs,pp
< 158 GeV
je
T
p126 <
0-10%
[GeV]
T
p
110
[%]
)
T
D(p
Rδ
20−
15−
10−
5−
0
5
10
15
20
25
JES
JER
Un olding
MC non-closu e
T acking
UE sub ac ion
To al
=0.4R
kan i-
|<2.1
je
y|
ATLAS -1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
-1
= 5.02 TeV, 25 pbs,pp
< 158 GeV
je
T
p126 <
0-10%
FIG. 5. Summa y o he sys ema ic unce ain ies o 0–10% cen al RD(z)(le ) and RD(pT)( igh ) a ios, o je s in he 126–158 GeV pje
T
in e al. The sys ema ic unce ain ies due o JES, JER, un olding, UE con ibu ion, MC nonclosu e, and acking a e shown along wi h he o al
sys ema ic unce ain y om all sou ces.
The UE dis ibu ions co ec ed o he addi i e con ibu ion
o ake acks, d˜
nUE+ ake
ch /dpch
Tand d˜
nUE+ ake
ch /dz, a e hen
sub ac ed om he measu ed dis ibu ions, and he sub ac ed
cha ged-pa icle yields and agmen a ion unc ions a e e alu-
a ed:
dnsub
ch
dz =dnmeas
ch
dz −d˜
nUE+ ake
ch
dz ,
Dsub(z)=1
Nmeas
je
dnsub
ch
dz ,
and
dnsub
ch
dpch
T=dnmeas
ch
dpch
T−d˜
nUE+ ake
ch
dpch
T
,
Dsubpch
T=1
Nmeas
je
dnsub
ch
dpch
T
,
whe e Nmeas
je is he o al numbe o measu ed je s in a gi en pje
T
in e al. The signal- o-backg ound a io, nsub
ch /nUE
ch , s ongly
depends on he collision cen ali y and pch
T. Figu e 2shows
he dis ibu ions p io o he UE and ake- ack sub ac ion,
dnmeas
ch
dpch
T
,di ided by he dis ibu ionsa e hesub ac ion, dnsub
ch
dpch
T
,
as a unc ion o pch
T o h ee cen ali y selec ions. In 0–10%
cen al collisions, he dis ibu ions p io o sub ac ion a e o e
en imes la ge han he sub ac ed dis ibu ions o he mos
ex eme case o 1 GeV cha ged pa icles. This a io is educed
o app oxima ely 2 in pe iphe al collisions a he same cha ged
pa icle pT. The ake- ack con ibu ion o he agmen a ion
unc ions is sub ac ed om he measu ed agmen a ion unc-
ions in bo h he pp and Pb+Pb collisions; he UE sub ac ion
is pe o med only o he Pb+Pb measu emen as he UE
con ibu ion is negligible in he pp collisions (less han 2%
o e he en i e kinema ic ange measu ed).
To emo e he e ec s o bin mig a ion due o he je ene gy
and ack momen um esolu ion, he sub ac ed dnsub
ch /dz
and dnsub
ch /dpch
Tdis ibu ions a e co ec ed by using a wo-
dimensional Bayesian un olding p ocedu e [42]inzo pT
and pje
Tas implemen ed in he RooUn old package [43].
Two-dimensionalun oldingisusedbecause hecalo ime icje
ene gy esponsedependson he agmen a ionpa e no heje
[44]. Using MC samples, ou -dimensional esponse ma ices
a e c ea ed using he gene a o -le el and econs uc ed pje
T,
and he gene a o -le el and econs uc ed cha ged-pa icle z
o pT. Sepa a e un olding ma ices a e cons uc ed o pp da a
and each cen ali y in e al in Pb+Pb collisions. A sepa a e
one-dimensional Bayesian un olding is used o co ec he
measu edpje
Tspec awhicha eused ono malize heun olded
unno malized agmen a ion unc ions, dnun olded
ch /dpTand
dnun olded
ch /dz. To achie e be e ag eemen wi h he da a, he
MC je spec a and agmen a ion unc ions a e eweigh ed o
ma ch he shapes in he econs uc ed da a. The Bayesian p o-
cedu e equi es a choice in he numbe o i e a ions. Addi ional
i e a ions educe he sensi i i y o he choice o p io , bu may
ampli y s a is ical luc ua ions in he dis ibu ions. A e ou
i e a ions o bo h he one-dimensional and wo-dimensional
un oldings he agmen a ion unc ions a e s able o bo h
he Pb+Pb and pp da a. The inal, pa icle-le el co ec ed
dis ibu ions a e de ined as
D(z)=1
Nun olded
je
dnun olded
ch
dz ,
D(pT)=1
Nun olded
je
dnun olded
ch
dpT
,
whe e Nun olded
je is he un olded numbe o je s in a gi en pje
T
in e al.
The pe o mance o he analysis p ocedu e is es ed by
di iding he MC e en s in hal and using one hal o gene a e
esponse ma ices wi h which he o he hal is un olded and he
a io o un olded o gene a o -le el agmen a ion unc ions4is
e alua ed. This p ocedu e es s all he analysis co ec ions and
he un olding p ocedu e. Good eco e y o he gene a o -le el
( u h) MC dis ibu ions is obse ed o he un olded e en s.
The de ia ions om he exac eco e y o he gene a o -
le el MC dis ibu ions, he nonclosu e, a e included in he
sys ema ic unce ain ies. The a ios o Dsub(z) and Dsub(pch
T)
dis ibu ions o he un olded D(z) and D(pT) dis ibu ions a e
4The gene a o -le el agmen a ion unc ions a e cons uc ed using
gene a o -le el je s and p ima y cha ged pa icles.
024908-7
M. AABOUD e al. PHYSICAL REVIEW C 98, 024908 (2018)
z
−2
10 −1
10 1
)z(D
−4
10
−2
10
1
2
10
4
10
6
10
8
10
| <2.1
je
y|
ATLAS
= 5.02 TeVs
,pp
-1
25 pb
=0.4R
kan i-
< 158 GeV x10p126 <
< 200 GeV x10p158 <
< 251 GeV x10p200 <
< 316 GeV x10p251 <
< 398 GeV x10p316 <
[GeV]
T
p
110 2
10
]
-1
) [GeV
T
p(D
−6
10
−3
10
1
3
10
6
10
| <2.1
je
y|
ATLAS
= 5.02 TeVs
,pp
-1
25 pb
=0.4R
kan i-
< 158 GeV x10p126 <
< 200 GeV x10p158 <
< 251 GeV x10p200 <
< 316 GeV x10p251 <
< 398 GeV x10p316 <
FIG. 6. F agmen a ion unc ions, D(z)(le )andD(pT) ( igh ), in pp collisions measu ed in i e pje
T anges om 126 o 398 GeV. The
e ical ba s on he da a poin s indica e s a is ical unce ain ies, while he shaded bands indica e sys ema ic unce ain ies. In mos cases, he
s a is ical unce ain ies a e smalle han he ma ke size.
shown in Fig. 3 o pp collisions and 0–10% cen al Pb+Pb
collisions. The magni ude o he un olding e ec a ies as a
unc ion o pje
T,pch
T, and cen ali y. The e ec o he un olding
is simila in pp and Pb+Pb collisions a low zand pT,bu
o highe -momen um pa icles wi hin he je , he e ec o he
un olding in pp and Pb+Pb collisions di e s by up o 25%
be ween he wo collision sys ems o 126 <p
je
T<158 GeV.
This di e ence is due o UE luc ua ions, which lead o poo e
je ene gy esolu ion in Pb+Pb collisions han in pp collisions.
Wi h inc easing pje
T, he e ec o UE luc ua ions dec eases;
o 251 <p
je
T<316 GeV he e ec o he un olding is simila
in Pb+Pb and pp collisions a all alue o zand pT. The e ec
o he un olding is la ge a high zand pTdue o he s eepness
o he agmen a ion unc ion nea z=1. The shaded boxes
in Fig. 3show he size o sys ema ic unce ain ies associa ed
wi h he un olding which o igina e om he sensi i i y o he
un olding o he shape o inpu MC dis ibu ions, as desc ibed
in he nex sec ion.
z
−2
10 1−
10 1
)z(D
4−
10
1−
10
2
10
5
10
8
10
| <2.1
je
y|
ATLAS
-1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
=0.4 je sR
kan i-
< 158 GeV
je
T
p 126 <
3
0 - 10% x 10 2
10 - 20% x 10 1
20 - 30% x 10 0
30 - 40% x 10 -1
40 - 60% x 10 -2
60 - 80% x 10
[GeV]
T
p
1 10
]
-1
) [GeV
T
p(D
6−
10
3−
10
1
3
10
6
10
| <2.1
je
y|
ATLAS
-1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
=0.4 je sR
kan i-
< 158 GeV
je
T
p 126 <
3
0 - 10% x 10 2
10 - 20% x 10 1
20 - 30% x 10 0
30 - 40% x 10 -1
40 - 60% x 10 -2
60 - 80% x 10
FIG. 7. F agmen a ion unc ions, D(z)(le )andD(pT) ( igh ), in Pb+Pb collisions measu ed in six di e en cen ali y classes o pje
To
126 o 158 GeV. The e ical ba s on he da a poin s indica e s a is ical unce ain ies, while he shaded bands indica e sys ema ic unce ain ies.
In mos cases, he s a is ical unce ain ies a e smalle han he ma ke size.
024908-8
MEASUREMENT OF JET FRAGMENTATION IN Pb+Pb AND … PHYSICAL REVIEW C 98, 024908 (2018)
z
2−
10 1−
10 1
)z(D
4−
10
1−
10
2
10
5
10
8
10
| <2.1
je
y|
ATLAS
-1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
=0.4 je sR
kan i-
< 200 GeV
je
T
p 158 <
3
0 - 10% x 10 2
10 - 20% x 10 1
20 - 30% x 10 0
30 - 40% x 10 -1
40 - 60% x 10 -2
60 - 80% x 10
[GeV]
T
p
1 10 2
10
]
-1
) [GeV
T
p(D
6−
10
3−
10
1
3
10
6
10
| <2.1
je
y|
ATLAS
-1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
=0.4 je sR
kan i-
< 200 GeV
je
T
p 158 <
3
0 - 10% x 10 2
10 - 20% x 10 1
20 - 30% x 10 0
30 - 40% x 10 -1
40 - 60% x 10 -2
60 - 80% x 10
FIG. 8. F agmen a ion unc ions, D(z)(le )andD(pT) ( igh ), in Pb+Pb collisions measu ed in six di e en cen ali y classes o pje
To
158 o 200 GeV. The e ical ba s on he da a poin s indica e s a is ical unce ain ies, while he shaded bands indica e sys ema ic unce ain ies.
In mos cases, he s a is ical unce ain ies a e smalle han he ma ke size.
VI. SYSTEMATIC UNCERTAINTIES
The ollowing sou ces o sys ema ic unce ain y a e con-
side ed: he je ene gy scale (JES), he je ene gy esolu ion
(JER), he sensi i i y o he un olding o he p io , he esidual
nonclosu e o he analysis p ocedu e, UE con ibu ion, and
acking- ela ed unce ain ies. Fo each a ia ion accoun ing
o a sou ce o sys ema ic unce ain y, he agmen a ion
unc ions and a ios o D(z) and D(pT) dis ibu ions in Pb+Pb
and pp collisions a e e-e alua ed. The di e ence be ween he
a ied and nominal dis ibu ions is used as an es ima e o he
esul ing unce ain y.
The sys ema ic unce ain y due o he JES in Pb+Pb
collisions is composed o wo pa s: a cen ali y-independen
baseline componen and a cen ali y-dependen componen .
Only he cen ali y-independen baseline componen is used
in pp collisions; i is de e mined om in si u s udies o he
calo ime e esponse [37,45,46], and s udies o he ela i e
z
2−
10 1−
10 1
)z(D
4−
10
1−
10
2
10
5
10
8
10
| <2.1
je
y|
ATLAS
-1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
=0.4 je sR
kan i-
< 251 GeV
je
T
p 200 <
3
0 - 10% x 10 2
10 - 20% x 10 1
20 - 30% x 10 0
30 - 40% x 10 -1
40 - 60% x 10 -2
60 - 80% x 10
[GeV]
T
p
1 10 2
10
]
-1
) [GeV
T
p(D
6−
10
3−
10
1
3
10
6
10
| <2.1
je
y|
ATLAS
-1
= 5.02 TeV, 0.49 nb
NN
sPb+Pb,
=0.4 je sR
kan i-
< 251 GeV
je
T
p 200 <
3
0 - 10% x 10 2
10 - 20% x 10 1
20 - 30% x 10 0
30 - 40% x 10 -1
40 - 60% x 10 -2
60 - 80% x 10
FIG. 9. F agmen a ion unc ions, D(z)(le )andD(pT) ( igh ), in Pb+Pb collisions measu ed in six di e en cen ali y classes o pje
To
200 o 251 GeV. The e ical ba s on he da a poin s indica e s a is ical unce ain ies, while he shaded bands indica e sys ema ic unce ain ies.
In mos cases, he s a is ical unce ain ies a e smalle han he ma ke size.
024908-9
M. AABOUD e al. PHYSICAL REVIEW C 98, 024908 (2018)
FIG. 17. Ra ios o D(pT) dis ibu ions in six cen ali y in e als o Pb+Pb collisions o pp collisions e alua ed in ou pje
T anges o
je s wi h 1.2<|yje |<2.1. The e ical ba s on he da a poin s indica e s a is ical unce ain ies, while he shaded bands indica e sys ema ic
unce ain ies. Cen ali y dec eases om op o bo om panels and pje
Tinc eases om le o igh panels.
VII. RESULTS
In his sec ion, esul s a e p esen ed o he measu emen
o he D(z) and D(pT) dis ibu ions o je pTbe ween 126
and 398 GeV and six cen ali y in e als in Pb+Pb collisions;
he same dis ibu ions a e p esen ed in pp collisions o he
same pje
T anges. In o de o s udy he e ec s o ho dense
ma e on he je agmen a ion p ocess, a ios o Pb+Pb
agmen a ion unc ions o pp agmen a ion unc ions a e
e alua ed.
The D(z) and D(pT) dis ibu ions in pp collisions a e
shown in Fig. 6. The co esponding dis ibu ions in Pb+Pb
collisions a e shown in Figs. 7–11.
In o de o quan i y he di e ence in he agmen a ion
unc ions be ween Pb+Pb and pp collisions, he a ios o D(z)
andD(pT)dis ibu ions measu edinPb+Pbcollisions o hose
measu ed in pp collisions, RD(z)and RD(pT), a e shown in
Figs. 12 and 13, espec i ely. In each igu e, he shaded boxes
indica e sys ema ic unce ain ies and he e ical ba s show he
s a is ical unce ain ies.
024908-16

MEASUREMENT OF JET FRAGMENTATION IN Pb+Pb AND … PHYSICAL REVIEW C 98, 024908 (2018)
FIG. 18. RD(z)(le ) and RD(pT)( igh ) o 126–158 GeV je s o collision ene gies o 5.02 TeV ( his analysis) and 2.76 TeV [16]. The
e ical ba s on he da a poin s indica e s a is ical unce ain ies while he boxes indica e sys ema ic unce ain ies.
The shapes o he RD(z)and RD(pT)dis ibu ions a e simila
o all cen ali ies: inside he je s; he yields o pa icles wi h
low pTo za e enhanced; he e is a educ ion o pa icles
wi h in e media e pTo z; and he yields o pa icles wi h
high pTo za e enhanced. This is quali a i ely consis en
wi h p e ious measu emen s o je agmen a ion a √sNN =
2.76 TeV [14–16]; a quan i a i e compa ison is p o ided in
Sec. VIII. The magni udes o he de ia ions o he a ios om
uni y dec ease wi h dec easing collision cen ali y. In he mos
cen al collisions, he size o he enhancemen is as la ge as
70% a low pTo zand 30% a high pTo z. The deple ion o
cha ged-pa icle yields a in e media e pTand zis as la ge as
20%.Insomecen ali yandpje
T anges he eisadec easeo he
agmen a ion unc ions a he highes z alues. In his egion
he s a is ical and sys ema ic unce ain ies a e he la ges ; mo e
p ecise measu emen s a e needed o de e mine i a signi ican
dec ease exis s.
Figu es 14 and 15 show he RD(z)dis ibu ions o je s in
he mos cen al and mos o wa d apidi y in e als, 0.0–0.3
and 1.2–2.1, espec i ely, o he six cen ali y in e als used
in his analysis and o ou pje
Tin e als: 126–158, 158–
200, 200–251, and 251–316 GeV. Figu es 16 and 17 show
RD(pT)dis ibu ions o he same je apidi y, cen ali y, and
pje
T anges. In all apidi y anges, he RD(z)and RD(pT)
dis ibu ions ha e he same quali a i e shape and cen ali y
dependence as he apidi y-inclusi e esul s p esen ed abo e.
VIII. DISCUSSION
In his sec ion, he esul s om he p e ious sec ion a e
u he discussed and compa ed o heo e ical models.
In o de o make a di ec compa ison wi h measu emen s a
2.76 TeV, Fig. 18 o e lays he RD(z)and RD(pT)dis ibu ions
measu ed in 2.76 TeV collisions [16] on hose ob ained in his
FIG. 19. RD(z)(le ) and RD(pT)( igh ) a ios o h ee pje
T anges: 126–158 GeV (ci cles), 200–251 GeV (diamonds), and 316–398 GeV
(c osses). The s a is ical unce ain ies a e shown as ba s and he sys ema ic unce ain ies as ou lined boxes.
024908-17
M. AABOUD e al. PHYSICAL REVIEW C 98, 024908 (2018)
FIG. 20. RD(z) o je swi h126 <p
je
T<158GeVcompa edwi h
calcula ions om Re . [51] (hyb id model) o R es =0 (do -dashed
cu e), R es =3 (dashed cu e), and o calcula ions om Re . [21]
(EQ model).
analysisa 5.02TeV.The womeasu emen sa he wocollision
ene gies quan i a i ely ag ee o e he en i e zand cha ged-
pa icle pT ange o he measu emen ; no signi ican collision
ene gy dependence is obse ed [ he lowes poin in he D(pT)
a ios di e s by less han wo s anda d de ia ions when he
s a is ical and sys ema ic unce ain ies a e combined].
In o de o de e mine how he agmen a ion unc ions
depend on pje
T, he agmen a ion unc ions om h ee pje
T
in e als a e compa ed in Fig. 19.TheD(pT) and D(z)
dis ibu ions a e closely ela ed o each o he , di e ing, p i-
ma ily, in he no maliza ion by pje
Tin he de ini ion o z[see
Eq. (1)]. The e o e, a compa ison o he modi ica ions o he
agmen a ion unc ions as a unc ion o pje
Tcan show whe he
he size o modi ica ions scales wi h cha ged-pa icle zo wi h
pT. The o me would be expec ed o agmen a ion e ec s,
and he la e migh indica e some scale in he QGP. The
la ge pje
T ange a ailable in his measu emen allows hese
wo scena ios o be dis inguished. Figu e 19 shows ha he
excess o so pa icles obse ed in cen al Pb+Pb collisions
exhibi s a much smalle pje
Tdependence o he D(pT) a ios
han o he D(z) a ios; he ansi ion om enhancemen o
supp ession o so agmen soccu sa pTa ound4GeV o all
pje
T alues in es iga ed in his analysis. The same compa ison
can be made o he ha d pa icles. In his case, Fig. 19 shows
ha he enhancemen o ha d agmen s wi h z0.3 is nea ly
independen o pje
T.
The agmen a ion unc ions ha e been calcula ed wi hin
a hyb id model o je quenching, which uses pe u ba i e
echniques o he high-Q2p ocesses in je e olu ion and
s ong coupling o he low momen um scales associa ed wi h
he QGP [50,51]. Wi hin his model, he e is a leng h scale
L eswhich can be in e p e ed as he minimum dis ance equi ed
o esol e a pa on as sepa a e om he o he s in he showe ing
p ocess when i occu s in he QGP medium. The scale L es
can be exp essed in e ms o he empe a u e o QGP, T,
FIG. 21. RD(pT) a ios o h ee pje
T anges: 126–158 GeV (ci -
cles), 200–251 GeV (diamonds), and 316–398 GeV (c osses) com-
pa ed wi h calcula ions om he hyb id model [51] wi h R es =3.
as L es =R es/πT whe e R es is a pa ame e o he model.
The agmen a ion unc ions measu ed he e a e compa ed wi h
calcula ions om his model in Fig. 20 o wo alues o R es.
Thecalcula ionswi hR es =3a equali a i ely consis en wi h
he measu emen a high zand pT.A lowzand pT, he esul s
o he calcula ions a e below he da a, in ag eemen wi h p io
obse a ions in compa isons o ela ed obse ables [52]. Also
shown in Fig. 20 is a calcula ion om Re . [21] which is a
phenomenological model, he e ec i e quenching (EQ) model,
inco po a ing ene gy-loss e ec s h ough wo downwa d shi s
in he pje
Tspec um: one o qua k-ini ia ed je s and a la ge
one o gluon-ini ia ed je s. In his case, he je s agmen as
in acuum, bu RD(z)di e s om uni y due o an inc ease in
he ac ion o qua k je s in Pb+Pb collisions ela i e o pp
collisions a a ixed pje
T. Since qua k je s a e mo e likely o
p oduce high-zpa icles han gluon je s [53,54] his causes
RD(z)>1a highzin he model p edic ions. The EQ model
does no ha e a desc ip ion o he so p ocesses om so
gluon adia ion o he esponse o he ho QCD ma e o he
je passing h ough i , so he compa ison wi h da a is only
app op ia e a z>0.1.
Figu e 21 shows a compa ison be ween measu ed RD(pT)
and hehyb idmodelcalcula ionwi h R es =3 o h eepje
Tin-
e als.Themagni udeo heenhancemen o high-pTpa icles
in he calcula ion ag ees wi h he obse a ions o pje
Tin he
anges 126–158 and 200–251 GeV. The RD(z) alues a e also
compa ed in Fig. 22 wi h a hi d model which uses calcula ions
based on so collinea e ec i e heo y (SCET) [55,56]. This
model well desc ibes RD(z)in he low and in e media e z
egions, bu does no ep oduce he enhancemen in he high-z
egion obse ed in he da a.
In o de o quan i y he magni ude o he low-pTenhance-
men in he D(pT) dis ibu ions in Pb+Pb collisions compa ed
o pp collisions, he di e ence be ween he wo dis ibu ions
is e alua ed o he pje
Tand cen ali y in e als used in his
024908-18
MEASUREMENT OF JET FRAGMENTATION IN Pb+Pb AND … PHYSICAL REVIEW C 98, 024908 (2018)
FIG. 22. RD(z) o h ee pje
T anges: 126–158 GeV (ci cles), 200–
251 GeV (diamonds), and 316–398 GeV (c osses) compa ed wi h
calcula ions om he SCET model [55,56].
analysis:
Nch|cen ≡pT,max
pT,min
[D(pT)|cen −D(pT)|pp ]dpT,
whe e “cen ” ep esen s one o he six cen ali y in e als,
and he alues o pT,min and pT,max a e bounda ies o he
low pTenhancemen egion, chosen o be 1.0 and 4.2 GeV,
espec i ely. In addi ion, he pT-weigh ed di e ence be ween
he same quan i ies is also compu ed:
Pch
Tcen ≡pT,max
pT,min
[D(pT)|cen −D(pT)|pp ]pTdpT.
The Pch
T|cen ep esen s he o al ans e se momen um ca ied
bypa iclesin helowpTenhancemen egion.Thedependence
o Nch|cen and Pch
T|cen on pje
Tand cen ali y is p esen ed
in Fig. 23. O e all, bo h quan i ies a e ound o inc ease
as a unc ion o pje
Tand collision cen ali y. In he mos
cen al collisions, Nch inc eases om app oxima ely 1.5 o 2.0
pa icles o e he pje
T ange o his measu emen . The amoun
o ans e se momen um ca ied by hese pa icles inc eases
om app oxima ely 2.5 o 4 GeV o e he same pje
T ange. In
pe iphe al collisions, he numbe o pa icles con ibu ing o
he enhancemen is much smalle , app oxima ely 0.2 pa icles
ca ying less han 0.5 GeV o ans e se momen um in he
lowes pje
T ange. These esul s a e in quali a i e ag eemen
wi h measu emen s o he same quan i ies in √sNN =2.76
TeV Pb+Pb collisions [16]; howe e , he pje
T anges a e no
he same as used in his analysis and he pje
Tdependence is no
epo ed in ha measu emen .
In o de o quan i y he apidi y dependence, he a io o
RD(z)in he apidi y in e als 0.3–0.8, 0.8–1.2, and 1.2–2.1 o
he RD(z)in |yje |<0.3 is shown in Fig. 24 o pje
Tin e als
o 126–158, 158–200, and 200–251 GeV and o 0–10%,
10–20%, and 20–30% cen al collisions. A simila quan i y
was epo ed in Re . [16] o 100–398 GeV je s a 2.76 TeV.
In ha measu emen , a small apidi y dependence o RD(z)is
obse ed a high z o je s wi h |yje |<0.8; howe e , no s ong
conclusion could be d awn due o he size o he unce ain ies.
The pje
Tin e als used in he measu emen p esen ed he e a e
selec ed o be simila o hose used in he measu emen o ag-
men a ion unc ions a 2.76 TeV. Fu he mo e, je s popula ing
he 200–251 GeV pje
Tin e al in collisions a 5.02 TeV ha e
simila ac ions o qua k- and gluon-ini ia ed je s as je s ha -
ing pTbe ween 126 and 158 GeV in 2.76 TeV collisions. The
a ioso RD(z)e alua edin a ious apidi yin e als o hemos
cen al apidi y RD(z)in di e en pje
Tin e als sugges wi h a
FIG. 23. Di e ence be ween Pb +Pb collisions and pp collisions in he o al yield o cha ged pa icles Nch|cen (le ), and di e ence in he
o al ans e se momen um ca ied by cha ged pa icles Pch
T|cen ( igh ) o pa icles wi h pT om 1 <p
T<4.2 GeV e alua ed as a unc ion
o pje
T o six cen ali y in e als. The e ical ba s on he da a poin s indica e s a is ical unce ain ies while he boxes indica e sys ema ic
unce ain ies.
024908-19
M. AABOUD e al. PHYSICAL REVIEW C 98, 024908 (2018)
FIG. 24. Ra io o he apidi y-selec ed RD(z)dis ibu ions o he RD(z)dis ibu ions measu ed in |yje |<0.3 o h ee pje
T anges and h ee
cen ali y in e als. The e ical ba s on he da a poin s indica e s a is ical unce ain ies while he shaded bands indica e sys ema ic unce ain ies.
FIG. 25. Compa ison o he measu ed a io o he apidi y-selec ed RD(z)dis ibu ions o he RD(z)dis ibu ions measu ed in |yje |<0.3
and he same quan i y e alua ed in he hyb id model [51] o R es =3 and in he EQ model [21]. The compa ison wi h he hyb id model is done
o h ee pje
T anges in 0–10% cen al collisions. The compa ison wi h he EQ model is shown o 126–158 GeV pje
Tin e al. The e ical ba s
on he da a poin s indica e s a is ical unce ain ies while he shaded ba s indica e sys ema ic unce ain ies. The band ep esen s he s a is ical
unce ain y o he calcula ions.
024908-20
MEASUREMENT OF JET FRAGMENTATION IN Pb+Pb AND … PHYSICAL REVIEW C 98, 024908 (2018)
low signi icance a small enhancemen o yields o agmen s
wi h low and in e media e zand educ ion o yields o high-z
agmen s o mo e o wa d je s in he mos cen al Pb +Pb
collisions. Howe e , he obse a ion o high-z agmen s is
o limi ed signi icance due o he limi ed size o he a ailable
da a sample. Figu e 25 shows he same a ios o he 0–10%
cen ali y in e al compa ed wi h calcula ions om he hyb id
model [51] and he e ec i e quenching model [21]. Bo h cal-
cula ions a e consis en wi h he da a o je s wi h |yje |<1.2
wi h la ge de ia ions in apidi y in e al 1.2<|yje |<2.1.
IX. SUMMARY
This pape p esen s an analysis o 0.49 nb−1o Pb+Pb
and 25 pb−1o pp collisions a √sNN =5.02 TeV using
da a collec ed wi h he ATLAS de ec o a he LHC in 2015.
The analysis measu es he agmen a ion unc ions o je s
in o cha ged pa icles and he dis ibu ions o cha ged-pa icle
ans e se momen a wi hin R=0.4 an i-k je s wi h |yje |<
2.1 and wi h pje
T om 126 o 398 GeV. The s udies a e
pe o med as a unc ion o he e en cen ali y, je apidi y, and
je ans e se momen um o cha ged pa icles wi h ans e se
momen um g ea e han 1 GeV.
Cen ali y-dependen modi ica ions o hese agmen a ion
unc ions in Pb+Pb collisions a e obse ed when compa ed
wi h hose measu ed in pp collisions. The magni ude o hese
modi ica ions inc eases wi h inc easing collision cen ali y.
The a ios o agmen a ion unc ions e alua ed in Pb+Pb
collisions o hose in pp collisions exhibi enhancemen s bo h
o ans e se momen um less han 4 GeV and o z0.3.
Be ween hese wo enhancemen s he e is a supp ession o
he agmen a ion unc ions in Pb+Pb collisions compa ed o
pp collisions. The enhancemen o yields o low and high
ans e se momen um agmen s is as la ge as 70% and 30%,
espec i ely, in cen al collisions. The deple ion o agmen
yields wi h in e media e pTand zis as la ge as 20%. The
di e ence in cha ged-pa icle mul iplici y and o al ans e se
momen um in Pb+Pb compa ed o pp collisions o 1.0<
pT<4.2 GeV ange inc eases wi h inc easing cen ali y and
je ans e se momen um. No signi ican dependence o he
high-zenhancemen on he ans e se momen um o he je
is obse ed. The SCET model desc ibes he low pTexcess
and he EQ and hyb id models desc ibe he high-zexcess,
bu none o he models desc ibes he modi ica ion o he ull
agmen a ion unc ions. A small inc ease in he modi ica ion
o yields o agmen s wi h low and in e media e zis obse ed
in o wa d je s compa ed o hose a cen al apidi y. These
measu emen sp o idenewin o ma ionabou heje ans e se
momen um and apidi y dependence o he modi ica ions o je
agmen a ion in Pb+Pb collisions and, oge he wi h o he je
measu emen s in hea y-ion collisions, will cons ain models
o je quenching in he QGP c ea ed in hea y-ion collisions.
ACKNOWLEDGMENTS
We hank CERN o he e y success ul ope a ion o he
LHC, as well as he suppo s a om ou ins i u ions wi hou
whom ATLAS could no be ope a ed e icien ly. We acknowl-
edge he suppo o ANPCyT, A gen ina; Ye PhI, A menia;
ARC, Aus alia; BMWFW and FWF, Aus ia; ANAS, Aze -
baijan; SSTC, Bela us; CNPq and FAPESP, B azil; NSERC,
NRC and CFI, Canada; CERN; CONICYT, Chile; CAS,
MOSTandNSFC, China;COLCIENCIAS,Colombia;MSMT
CR, MPO CR and VSC CR, Czech Republic; DNRF and
DNSRC, Denma k; IN2P3-CNRS, CEA-DRF/IRFU, F ance;
SRNSFG, Geo gia; BMBF, HGF, and MPG, Ge many; GSRT,
G eece; RGC, Hong Kong SAR, China; ISF, I-CORE and
Benoziyo Cen e , Is ael; INFN, I aly; MEXT and JSPS,
Japan; CNRST, Mo occo; NWO, Ne he lands; RCN, No -
way; MNiSW and NCN, Poland; FCT, Po ugal; MNE/IFA,
Romania; MES o Russia and NRC KI, Russian Fede a ion;
JINR; MESTD, Se bia; MSSR, Slo akia; ARRS and MIZŠ,
Slo enia; DST/NRF, Sou h A ica; MINECO, Spain; SRC and
Wallenbe g Founda ion, Sweden; SERI, SNSF and Can ons
o Be n and Gene a, Swi ze land; MOST, Taiwan; TAEK,
Tu key; STFC, Uni ed Kingdom; DOE and NSF, Uni ed
S a es o Ame ica. In addi ion, indi idual g oups and membe s
ha e ecei ed suppo om BCKDF, he Canada Council,
CANARIE, CRC, Compu e Canada, FQRNT, and he On a io
Inno a ion T us , Canada; EPLANET, ERC, ERDF, FP7,
Ho izon 2020 and Ma ie Skłodowska-Cu ie Ac ions, Eu o-
pean Union; In es issemen s d’A eni Labex and Idex, ANR,
Région Au e gne and Fonda ion Pa age le Sa oi , F ance;
DFG and A H Founda ion, Ge many; He aklei os, Thales and
A is eia p og ammes co- inanced by EU-ESF and he G eek
NSRF; BSF, GIF and Mine a, Is ael; BRF, No way; CERCA
P og amme Gene ali a de Ca alunya, Gene ali a Valenciana,
Spain; he Royal Socie y and Le e hulme T us , Uni ed King-
dom. The c ucial compu ing suppo om all WLCG pa ne s
is acknowledged g a e ully, in pa icula om CERN, he
ATLAS Tie -1 acili ies a TRIUMF (Canada), NDGF (Den-
ma k, No way, Sweden), CC-IN2P3 (F ance), KIT/G idKA
(Ge many), INFN-CNAF (I aly), NL-T1 (Ne he lands), PIC
(Spain), ASGC (Taiwan), RAL (UK), and BNL (USA), he
Tie -2 acili ies wo ldwide, and la ge non-WLCG esou ce
p o ide s.Majo con ibu o so compu ing esou cesa e lis ed
in Re . [57].
[1] G. Roland, K. Ša aˇ ík, and P. S einbe g, Hea y-ion collisions a
he LHC, P og. Pa . Nucl. Phys. 77,70 (2014).
[2] W. Busza, K. Rajagopal, and W. an de Schee, Hea y
ion collisions: The big pic u e, and he big ques ions,
a Xi :1802.04801.
[3] ALICE Collabo a ion, Measu emen o cha ged je supp ession
in Pb-Pb collisions a √sNN =2.76 TeV, J. High Ene gy Phys.
03 (2014)013.
[4] ATLAS Collabo a ion, Measu emen s o he Nuclea Modi ica-
ion Fac o o Je s in Pb+Pb Collisions a √sNN =2.76 TeV
wi h he ATLAS De ec o , Phys. Re . Le . 114,072302 (2015).
[5] CMS Collabo a ion, Measu emen o inclusi e je c oss sec ions
in pp and PbPb collisions a √sNN =2.76 TeV, Phys. Re . C
96,015202 (2017).
[6] ATLAS Collabo a ion, Obse a ion o a Cen ali y-Dependen
Dije Asymme y in Lead-Lead Collisions a √sNN =2.77 TeV
024908-21

M. AABOUD e al. PHYSICAL REVIEW C 98, 024908 (2018)
wi h he ATLAS De ec o a he LHC, Phys. Re . Le . 105,
252303 (2010).
[7] CMS Collabo a ion, Obse a ion and s udies o je quenching in
PbPb collisions a √sNN =2.76 TeV, Phys.Re .C84,024906
(2011).
[8] ATLAS Collabo a ion, Measu emen o je pTco ela ions in
Pb+Pb and pp collisions a √sNN =2.76 TeV wi h he ATLAS
de ec o , Phys. Le . B 774,379 (2017).
[9] CMS Collabo a ion, S udies o je quenching using isola ed-
pho on+je co ela ions in PbPb and pp collisions a √sNN =
2.76 TeV, Phys. Le . B 718,773 (2013).
[10] K. Adcox e al. (PHENIX Collabo a ion), Supp ession o
Had ons wi h La ge T ans e se Momen um in Cen al Au+Au
Collisions a √sNN =130-GeV, Phys. Re . Le . 88,022301
(2002).
[11] C. Adle e al. (STAR Collabo a ion), Disappea ance o Back-
o-Back High pTHad on Co ela ions in Cen al Au+Au Colli-
sions a √sNN =200-GeV, Phys.Re .Le .90,082302 (2003).
[12] B. I. Abele e al. (STAR Collabo a ion), Pa on ene gy loss
in hea y-ion collisions ia di ec -pho on and cha ged-pa icle
azimu hal co ela ions, Phys. Re . C 82,034909 (2010).
[13] CMS Collabo a ion, Modi ica ion o je shapes in PbPb colli-
sions a √sNN =2.76 TeV, Phys. Le . B 730,243 (2014).
[14] ATLAS Collabo a ion, Measu emen o inclusi e je cha ged-
pa icle agmen a ion unc ions in Pb+Pb collisions a √sNN =
2.76 TeV wi h he ATLAS de ec o , Phys. Le . B 739,320
(2014).
[15] CMS Collabo a ion, Measu emen o je agmen a ion in PbPb
and pp collisions a √sNN =2.76 TeV, Phys. Re . C 90,024908
(2014).
[16] ATLAS Collabo a ion, Measu emen o je agmen a ion in
Pb+Pb and pp collisions a √sNN =2.76 TeV wi h he ATLAS
de ec o a he LHC, Eu .Phys.J.C77,379 (2017).
[17] CMS Collabo a ion, Decomposing ans e se momen um bal-
ance con ibu ions o quenched je s in PbPb collisions a
√sNN =2.76 TeV, J. High Ene gy Phys. 11 (2016)055.
[18] CMS Collabo a ion, Je p ope ies in PbPb and pp collisions a
√sNN =5.02 TeV, J. High Ene gy Phys. 05 (2018)006.
[19] G.-Y. Qin and X.-N. Wang, Je quenching in high-ene gy hea y-
ion collisions, In . J. Mod. Phys. E 24,1530014 (2015).
[20] J.-P. Blaizo , Y. Meh a -Tani, and M. A. C. To es, Angula
S uc u e o he in-Medium QCD Cascade, Phys. Re . Le . 114,
222002 (2015).
[21] M. Spous a and B. Cole, In e p e ing single je measu emen s in
Pb +Pb collisions a he LHC, Eu .Phys.J.C76,50 (2016).
[22] ATLASCollabo a ion,Measu emen o je agmen a ionin5.02
TeV p o on–lead and p o on–p o on collisions wi h he ATLAS
de ec o , Nucl. Phys. A 978,65 (2018).
[23] ATLAS Collabo a ion, Measu emen o he cha ged-pa icle
mul iplici y inside je s om √s=8TeVpp collisions wi h
he ATLAS de ec o , Eu . Phys. J. C 76,322 (2016).
[24] M. Caccia i, G. P. Salam, and G. Soyez, The an i-k je clus e ing
algo i hm, J. High Ene gy Phys. 04 (2008)063.
[25] ATLAS Collabo a ion, The ATLAS Expe imen a he CERN
La ge Had on Collide , J. Ins um. 3, S08003 (2008).
[26] ATLAS Collabo a ion, ATLAS Inse able B-Laye Technical
Design Repo No. ATLAS-TDR-19, 2010.
[27] ATLAS Collabo a ion, ATLAS Inse able B-Laye Technical
Design Repo Addendum No. ATLAS-TDR-19-ADD-1, 2012.
[28] ATLAS Collabo a ion, Measu emen o longi udinal low de-
co ela ions in Pb+Pb collisions a √sNN =2.76 and 5.02
TeV wi h he ATLAS de ec o , Eu .Phys.J.C78,142
(2018).
[29] P. Nason, A new me hod o combining NLO QCD wi h showe
Mon e Ca lo algo i hms J. High Ene gy Phys. 11 (2004)040.
[30] T. Sjös and, S. Ask, J. R. Ch is iansen, R. Co ke, N. Desai, P.
Il en,S.M enna,S.P es el,C.O.Rasmussen,andP.Z.Skands,
An in oduc ion o PYTHIA8.2, Compu . Phys. Commun. 191,
159 (2015).
[31] ATLAS Collabo a ion, ATLAS Run 1 PYTHIA8 unes, ATLAS-
PHYS-PUB-2014-021, 2014.
[32] R. D. Ball e al., Pa on dis ibu ions wi h LHC da a, Nucl. Phys.
B867,244 (2013).
[33] S. Agos inelli e al. (GEANT4 Collabo a ion), GEANT4-a
simula ion oolki , Nucl. Ins um. Me hods Phys. Res. A 506,
250 (2003).
[34] ATLAS Collabo a ion, The ATLAS simula ion in as uc u e
Eu .Phys.J.C70,823 (2010).
[35] X.-N.WangandM.Gyulassy,HIJING:AMon eCa lomodel o
mul iple je p oduc ion in pp, pA and AA collisions, Phys. Re .
D44,3501 (1991).
[36] ATLAS Collabo a ion, Measu emen o he azimu hal
aniso opy o cha ged pa icle p oduc ion in √sNN =2.76 TeV
lead-lead collisions wi h he ATLAS de ec o , Phys.Re .C86,
014907 (2012).
[37] ATLAS Collabo a ion, Je ene gy scale measu emen s and hei
sys ema ic unce ain ies in p o on-p o on collisions a √s=13
TeV wi h he ATLAS de ec o , Phys. Re . D 96,072002 (2017).
[38] ATLAS Collabo a ion, P ope ies o je s and inpu s o je
econs uc ion and calib a ion wi h he ATLAS de ec o using
p o on–p o on collisions a √s=13 TeV, ATL-PHYS-PUB-
2015-036, 2015, h ps://cds.ce n.ch/ eco d/2044564
[39] ATLAS Collabo a ion, S udy o pho on-je momen um
co ela ions in Pb+Pb and pp collisions a √sNN =
5.02 TeV wi h ATLAS, ATLAS-CONF-2016-110, 2016,
h ps://cds.ce n.ch/ eco d/2220772
[40] ATLAS Collabo a ion, Pe o mance o he ATLAS ack e-
cons uc ion algo i hms in dense en i onmen s in LHC Run 2,
Eu .Phys.J.C77,673 (2017).
[41] ATLAS Collabo a ion, Measu emen o ack econs uc ion
ine iciencies in he co e o je s ia pixel dE/dx wi h he ATLAS
expe imen using √s=13 TeVpp collision da a, ATL-PHYS-
PUB-2016-007, 2016, h ps://cds.ce n.ch/ eco d/2140460
[42] G. D’Agos ini, A mul idimensional un olding me hod based on
Bayes’ heo em, Nucl. Ins um. Me hods Phys. Res. A 362,487
(1995).
[43] T. Adye, Un olding algo i hms and es s using RooUn old,
P oceedings o he PHYSTAT 2009 Wo kshop, CERN,
Gene a, Swi ze land, CERN-2011-006 (2011), p. 313,
doi: 10.5170/CERN-2011-006.313.
[44] ATLAS Collabo a ion,Je ene gymeasu emen wi h he ATLAS
de ec o in p o on-p o on collisions a √s=7TeV,Eu . Phys.
J. C 73,2304 (2013).
[45] ATLAS Collabo a ion, Je ene gy scale and i s unce ain y o
je s econs uc ed using he ATLAS hea y ion je algo i hm,
ATLAS-CONF-2015-016, 2015.
[46] ATLAS Collabo a ion, Je calib a ion and sys ema ic unce ain-
ies o je s econs uc edin heATLASde ec o a √s=13TeV,
ATLAS-PHYS-PUB-2015-015, 2015.
[47] ATLAS Collabo a ion, Je ene gy esolu ion in p o on-p o on
collisions a √s=7 TeV eco ded in 2010 wi h he ATLAS
de ec o , Eu . Phys. J. C 73,2306 (2013).
024908-22
MEASUREMENT OF JET FRAGMENTATION IN Pb+Pb AND … PHYSICAL REVIEW C 98, 024908 (2018)
[48] ATLAS Collabo a ion, Da a-d i en de e mina ion o he en-
e gy scale and esolu ion o je s econs uc ed in he ATLAS
calo ime e s using dije and mul ije e en s a √s=8 TeV,
ATLAS-CONF-2015-017, 2015.
[49] ATLAS Collabo a ion, Ea ly Inne De ec o T acking
Pe o mance in he 2015 Da a a √s=13 TeV, 2015,
h ps://cds.ce n.ch/ eco d/2110140
[50] J. Casalde ey-Solana, D. C. Gulhan, J. G. Milhano, D. Pablos,
and K. Rajagopal, A hyb id s ong/weak coupling app oach o
je quenching, J. High Ene gy Phys. 10 (2014)019;09 (2015)
175(E).
[51] Z. Hulche , D. Pablos, and K. Rajagopal, Resolu ion e ec s in
he hyb id s ong/weak coupling model, J. High Ene gy Phys.
03 (2018)010.
[52] J. Casalde ey-Solana, D. C. Gulhan, J. G. Milhano, D. Pablos,
and K. Rajagopal, Angula s uc u e o je quenching wi hin a
hyb id s ong/weak coupling model, J. High Ene gy Phys. 03
(2017)135.
[53] R. Ba a e e al. (ALEPH Collabo a ion), Measu emen s o he
s uc u e o qua k and gluon je s in had onic Z decays, Eu . Phys.
J. C 17,1(2000).
[54] G. Abbiendi e al. (OPAL Collabo a ion), Expe imen al p ope -
ies o gluon and qua k je s om a poin sou ce, Eu .Phys.J.C
11,217 (1999).
[55] Y.-T. Chien, A. Eme man, Z.-B. Kang, G. O anesyan, and I.
Vi e , Je quenching om QCD e olu ion, Phys. Re . D 93,
074030 (2016).
[56] Z.-B. Kang, F. Ringe , and I. Vi e , Inclusi e p oduc ion o
small adius je s in hea y-ion collisions, Phys. Le . B 769,242
(2017).
[57] ATLAS Collabo a ion,ATLASCompu ing Acknowledgemen s,
ATL-GEN-PUB-2016-002,h ps://cds.ce n.ch/ eco d/2202407
M. Aaboud,34d G. Aad,99 B. Abbo ,124 O. Abdino ,13,aB. Abeloos,128 D. K. Abhayasinghe,91 S. H. Abidi,164
O. S. AbouZeid,39 N. L. Ab aham,153 H. Ab amowicz,158 H. Ab eu,157 Y. Abulai i,6B. S. Acha ya,64a,64b,bS. Adachi,160
L. Adamczyk,81a J. Adelman,119 M. Ade sbe ge ,112 A. Adiguzel,12c,cT. Adye,141 A. A. A olde ,143 Y. A ik,157
C. Agheo ghiesei,27c J. A. Aguila -Saa ed a,136 ,136a F. Ahmado ,77,dG. Aielli,71a,71b S. Aka suka,83 T. P. A. ˚
Akesson,94
E. Akilli,52 A. V. Akimo ,108 G. L. Albe ghi,23b,23a J. Albe ,173 P. Albicocco,49 M. J. Alconada Ve zini,86 S. Alde wei eld ,117
M. Aleksa,35 I. N. Aleksand o ,77 C. Alexa,27b T. Alexopoulos,10 M. Alh oob,124 B. Ali,138 G. Alimon i,66a J. Alison,36
S. P. Alki e,145 C. Allai e,128 B. M. M. Allb ooke,153 B. W. Allen,127 P. P. Allpo ,21 A. Aloisio,67a,67b A. Alonso,39 F. Alonso,86
C. Alpigiani,145 A. A. Alsheh i,55 M. I. Als a y,99 B. Al a ez Gonzalez,35 D. Ál a ez Pique as,171 M. G. Al iggi,67a,67b
B. T. Amadio,18 Y. Ama al Cou inho,78b L. Amb oz,131 C. Amelung,26 D. Amidei,103 S. P. Amo Dos San os,136a,136c
S. Amo oso,44 C. S. Am ouche,52 C. Anas opoulos,146 L. S. Ancu,52 N. Anda i,21 T. Andeen,11 C. F. Ande s,59b J. K. Ande s,20
K. J. Ande son,36 A. And eazza,66a,66b V. And ei,59a C. R. Anelli,173 S. Angelidakis,37 I. Angelozzi,118 A. Ange ami,38
A. V. Anisenko ,120b,120a A. Anno i,69a C. An el,59a M. T. An hony,146 M. An onelli,49 D. J. A. An im,168 F. Anulli,70a
M. Aoki,79 L. Ape io Bella,35 G. A abidze,104 J. P. A aque,136a V. A aujo Fe az,78b R. A aujo Pe ei a,78b A. T. H. A ce,47
R. E. A dell,91 F. A. A duh,86 J-F. A guin,107 S. A gy opoulos,75 A. J. A mb us e ,35 L. J. A mi age,90 A A ms ong,168
O. A naez,164 H. A nold,118 M. A a ia,31 O. A slan,24 A. A amono ,109,aG. A oni,131 S. A z,97 S. Asai,160 N. Asbah,44
A. Ashkenazi,158 E. M. Asimakopoulou,169 L. Asqui h,153 K. Assamagan,29 R. As alos,28a R. J. A kin,32a M. A kinson,170
N. B. A lay,148 K. Augs en,138 G. A olio,35 R. A amidou,58a M. K. Ayoub,15a G. Azuelos,107,eA. E. Baas,59a M. J. Baca,21
H. Bachacou,142 K. Bachas,65a,65b M. Backes,131 P. Bagnaia,70a,70b M. Bahmani,82 H. Bah asemani,149 A. J. Bailey,171
J. T. Baines,141 M. Bajic,39 C. Bakalis,10 O. K. Bake ,180 P. J. Bakke ,118 D. Bakshi Gup a,93 E. M. Baldin,120b,120a P. Balek,177
F. Balli,142 W. K. Balunas,133 J. Balz,97 E. Banas,82 A. Bandyopadhyay,24 S. Bane jee,178, A. A. E. Bannou a,179 L. Ba ak,158
W. M. Ba be,37 E. L. Ba be io,102 D. Ba be is,53b,53a M. Ba be o,99 T. Ba illa i,113 M-S. Ba isi s,35 J. Ba keloo,127
T. Ba klow,150 N. Ba low,31 R. Ba nea,157 S. L. Ba nes,58c B. M. Ba ne ,141 R. M. Ba ne ,18 Z. Ba no ska-Blenessy,58a
A. Ba oncelli,72a G. Ba one,26 A. J. Ba ,131 L. Ba anco Na a o,171 F. Ba ei o,96 J. Ba ei o Guima ães da Cos a,15a
R. Ba oldus,150 A. E. Ba on,87 P. Ba os,28a A. Basalae ,134 A. Bassala ,128 R. L. Ba es,55 S. J. Ba is a,164 S. Ba lamous,34e
J. R. Ba ley,31 M. Ba aglia,143 M. Bauce,70a,70b F. Baue ,142 K. T. Baue ,168 H. S. Bawa,150,gJ. B. Beacham,122 M. D. Bea ie,87
T. Beau,132 P. H. Beauchemin,167 P. Bech le,24 H. C. Beck,51 H. P. Beck,20,hK. Becke ,50 M. Becke ,97 C. Beco ,44
A. Beddall,12d A. J. Beddall,12a V. A. Bednyako ,77 M. Bedogne i,118 C. P. Bee,152 T. A. Bee mann,35 M. Begalli,78b
M. Begel,29 A. Behe a,152 J. K. Beh ,44 A. S. Bell,92 G. Bella,158 L. Bellagamba,23b A. Belle i e,33 M. Bellomo,157 P. Bellos,9
K. Belo skiy,110 N. L. Belyae ,110 O. Bena y,158,aD. Benchek oun,34a M. Bende ,112 N. Benekos,10 Y. Benhammou,158
E. Benha Noccioli,180 J. Beni ez,75 D. P. Benjamin,47 M. Benoi ,52 J. R. Bensinge ,26 S. Ben elsen,118 L. Be es o d,131
M. Be e a,49 D. Be ge,44 E. Be geaas Kuu mann,169 N. Be ge ,5L. J. Be gs en,26 J. Be inge ,18 S. Be lendis,7N. R. Be na d,100
G. Be na di,132 C. Be nius,150 F. U. Be nlochne ,24 T. Be y,91 P. Be a,97 C. Be ella,15a G. Be oli,43a,43b I. A. Be am,87
G. J. Besjes,39 O. Bessidskaia Bylund,43a,43b M. Bessne ,44 N. Besson,142 A. Be hani,98 S. Be hke,113 A. Be i,24 A. J. Be an,90
J. Beye ,113 R. M. B. Bianchi,135 O. Biebel,112 D. Biede mann,19 R. Bielski,98 K. Bie wagen,97 N. V. Biesuz,69a,69b
M. Biglie i,72a T. R. V. Billoud,107 M. Bindi,51 A. Bingul,12d C. Bini,70a,70b S. Biondi,23b,23a M. Bi man,177 T. Bisanz,51
J. P. Biswal,158 C. Bi ich,46 D. M. Bje gaa d,47 J. E. Black,150 K. M. Black,25 T. Blazek,28a I. Bloch,44 C. Blocke ,26 A. Blue,55
U. Blumenschein,90 D . Blunie ,144a G. J. Bobbink,118 V. S. Bob o niko ,120b,120a S. S. Bocche a,94 A. Bocci,47 D. Boe ne ,179
D. Boga ac,112 A. G. Bogdanchiko ,120b,120a C. Bohm,43a V. Bois e ,91 P. Bokan,169,iT. Bold,81a A. S. Boldy e ,111
024908-23
M. AABOUD e al. PHYSICAL REVIEW C 98, 024908 (2018)
A. E. Bolz,59b M. Bomben,132 M. Bona,90 J. S. Bonilla,127 M. Boonekamp,142 A. Bo iso ,140 G. Bo isso ,87 J. Bo eld ,35
D. Bo ole o,131 V. Bo olo o,71a,61b,61c,71b D. Bosche ini,23b M. Bosman,14 J. D. Bossio Sola,30 K. Bouaouda,34a
J. Boud eau,135 E. V. Bouho a-Thacke ,87 D. Boumediene,37 C. Bou da ios,128 S. K. Bou le,55 A. Bo eia,122 J. Boyd,35
I. R. Boyko,77 A. J. Bozson,91 J. B acinik,21 N. B ahimi,99 A. B and ,8G. B and ,179 O. B and ,59a F. B a en,44 U. B a zle ,161
B. B au,100 J. E. B au,127 W. D. B eaden Madden,55 K. B endlinge ,44 A. J. B ennan,102 L. B enne ,44 R. B enne ,169
S. B essle ,177 B. B ickwedde,97 D. L. B iglin,21 D. B i on,55 D. B i zge ,59b I. B ock,24 R. B ock,104 G. B ooijmans,38
T. B ooks,91 W. K. B ooks,144b E. B os ,119 J. H B ough on,21 P. A. B uckman de Rens om,82 D. B uncko,28b A. B uni,23b
G. B uni,23b L. S. B uni,118 S. B uno,71a,71b B. H. B un ,31 M. B uschi,23b N. B uscino,135 P. B yan ,36 L. B yngema k,44
T. Buanes,17 Q. Bua ,35 P. Buchholz,148 A. G. Buckley,55 I. A. Budago ,77 F. Bueh e ,50 M. K. Bugge,130 O. Buleko ,110
D. Bullock,8T. J. Bu ch,119 S. Bu din,88 C. D. Bu ga d,118 A. M. Bu ge ,5B. Bu ghg a e,119 K. Bu ka,82 S. Bu ke,141
I. Bu meis e ,45 J. T. P. Bu ,131 D. Büsche ,50 V. Büsche ,97 E. Buschmann,51 P. Bussey,55 J. M. Bu le ,25 C. M. Bu a ,55
J. M. Bu e wo h,92 P. Bu i,35 W. Bu inge ,35 A. Buza u,155 A. R. Buzykae ,120b,120a G. Cab as,23b,23a S. Cab e a U bán,171
D. Ca o io,138 H. Cai,170 V. M. M. Cai o,2O. Caki ,4a N. Calace,52 P. Cala iu a,18 A. Caland i,99 G. Calde ini,132 P. Cal ayan,63
G. Callea,40b,40a L. P. Caloba,78b S. Cal en e Lopez,96 D. Cal e ,37 S. Cal e ,37 T. P. Cal e ,152 M. Cal e i,69a,69b
R. Camacho To o,132 S. Cama da,35 P. Cama i,71a,71b D. Came on,130 R. Caminal A madans,100 C. Caminche ,35 S. Campana,35
M. Campanelli,92 A. Camplani,39 A. Campo e de,148 V. Canale,67a,67b M. Cano B e ,58c J. Can e o,125 T. Cao,158 Y. Cao,170
M. D. M. Capeans Ga ido,35 I. Cap ini,27b M. Cap ini,27b M. Capua,40b,40a R. M. Ca bone,38 R. Ca da elli,71a F. C. Ca dillo,50
I. Ca li,139 T. Ca li,35 G. Ca lino,67a B. T. Ca lson,135 L. Ca mina i,66a,66b R. M. D. Ca ney,43a,43b S. Ca on,117 E. Ca quin,144b
S. Ca á,66a,66b G. D. Ca illo-Mon oya,35 D. Casadei,32b M. P. Casado,14,jA. F. Casha,164 M. Casolino,14 D. W. Caspe ,168
R. Cas elijn,118 F. L. Cas illo,171 V. Cas illo Gimenez,171 N. F. Cas o,136a,136e A. Ca inaccio,35 J. R. Ca mo e,130 A. Ca ai,35
J. Caud on,24 V. Ca alie e,29 E. Ca alla o,14 D. Ca alli,66a M. Ca alli-S o za,14 V. Ca asinni,69a,69b E. Celebi,12b
F. Ce adini,72a,72b L. Ce da Albe ich,171 A. S. Ce quei a,78a A. Ce i,153 L. Ce i o,71a,71b F. Ce u i,18 A. Ce elli,23b,23a
S. A. Ce in,12b A. Cha aq,34a D Chak abo y,119 S. K. Chan,57 W. S. Chan,118 Y. L. Chan,61a J. D. Chapman,31 D. G. Cha l on,21
C. C. Chau,33 C. A. Cha ez Ba ajas,153 S. Che,122 A. Chegwidden,104 S. Chekano ,6S. V. Chekulae ,165a G. A. Chelko ,77,k
M. A. Chels owska,35 C. Chen,58a C. H. Chen,76 H. Chen,29 J. Chen,58a J. Chen,38 S. Chen,133 S. J. Chen,15c X. Chen,15b,l
Y. Chen,80 Y-H. Chen,44 H. C. Cheng,103 H. J. Cheng,15d A. Cheplako ,77 E. Che emushkina,140 R. Che kaoui El Mou sli,34e
E. Cheu,7K. Cheung,62 L. Che alie ,142 V. Chia ella,49 G. Chia elli,69a G. Chiodini,65a A. S. Chisholm,35 A. Chi an,27b
I. Chiu,160 Y. H. Chiu,173 M. V. Chizho ,77 K. Choi,63 A. R. Chomon ,128 S. Chou idou,159 Y. S. Chow,118 V. Ch is odoulou,92
M. C. Chu,61a J. Chudoba,137 A. J. Chuina d,101 J. J. Chwas owski,82 L. Chy ka,126 D. Cinca,45 V. Cind o,89 I. A. Cioa ˘a,24
A. Ciocio,18 F. Ci o o,67a,67b Z. H. Ci on,177 M. Ci e io,66a A. Cla k,52 M. R. Cla k,38 P. J. Cla k,48 C. Clemen ,43a,43b
Y. Coadou,99 M. Cobal,64a,64c A. Cocca o,53b,53a J. Coch an,76 A. E. C. Coimb a,177 L. Colasu do,117 B. Cole,38 A. P. Colijn,118
J. Collo ,56 P. Conde Muiño,136a,136b E. Conia i is,50 S. H. Connell,32b I. A. Connelly,98 S. Cons an inescu,27b F. Con en i,67a,m
A. M. Coope -Sa ka ,131 F. Co mie ,172 K. J. R. Co mie ,164 M. Co adi,70a,70b E. E. Co igan,94 F. Co i eau,101,n
A. Co es-Gonzalez,35 M. J. Cos a,171 D. Cos anzo,146 G. Co in,31 G. Cowan,91 B. E. Cox,98 J. C ane,98 K. C anme ,121
S. J. C awley,55 R. A. C eage ,133 G. C ee,33 S. C épé-Renaudin,56 F. C escioli,132 M. C is inziani,24 V. C o ,121
G. C ose i,40b,40a A. Cue o,96 T. Cuhada Donszelmann,146 A. R. Cukie man,150 J. Cú h,97 S. Czekie da,82 P. Czod owski,35
M. J. Da Cunha Sa gedas De Sousa,58b,136b C. Da Via,98 W. Dab owski,81a T. Dado,28a,iS. Dahbi,34e T. Dai,103 F. Dallai e,107
C. Dallapiccola,100 M. Dam,39 G. D’amen,23b,23a J. Damp,97 J. R. Dandoy,133 M. F. Dane i,30 N. P. Dang,178, N. D Dann,98
M. Danninge ,172 V. Dao,35 G. Da bo,53b S. Da mo a,8O. Da si,5A. Da agup a,127 T. Daubney,44 S. D’Au ia,55 W. Da ey,24
C. Da id,44 T. Da idek,139 D. R. Da is,47 E. Dawe,102 I. Dawson,146 K. De,8R. De Asmundis,67a A. De Benede i,124 M. De
Beu s,118 S. De Cas o,23b,23a S. De Cecco,70a,70b N. De G oo ,117 P. de Jong,118 H. De la To e,104 F. De Lo enzi,76 A. De
Ma ia,51,oD. De Pedis,70a A. De Sal o,70a U. De Sanc is,71a,71b A. De San o,153 K. De Vasconcelos Co ga,99 J. B. De Vi ie De
Regie,128 C. Debenede i,143 D. V. Dedo ich,77 N. Dehghanian,3M. Del Gaudio,40b,40a J. Del Peso,96 Y. Delaba Diaz,44
D. Delgo e,128 F. Delio ,142 C. M. Deli zsch,7M. Della Pie a,67a,67b D. Della Volpe,52 A. Dell’Acqua,35 L. Dell’As a,25
M. Delmas o,5C. Delpo e,128 P. A. Delsa ,56 D. A. DeMa co,164 S. Deme s,180 M. Demiche ,77 S. P. Deniso ,140
D. Denysiuk,118 L. D’E amo,132 D. De enda z,82 J. E. De kaoui,34d F. De ue,132 P. De an,88 K. Desch,24 C. De e e,44
K. De e,164 M. R. De esa,30 P. O. De i ei os,35 A. Dewhu s ,141 S. Dhaliwal,26 F. A. Di Bello,52 A. Di Ciaccio,71a,71b
L. Di Ciaccio,5W. K. Di Clemen e,133 C. Di Dona o,67a,67b A. Di Gi olamo,35 B. Di Micco,72a,72b R. Di Na do,100
K. F. Di Pe illo,57 A. Di Simone,50 R. Di Sipio,164 D. Di Valen ino,33 C. Diaconu,99 M. Diamond,164 F. A. Dias,39
T. Dias Do Vale,136a M. A. Diaz,144a J. Dickinson,18 E. B. Diehl,103 J. Die ich,19 S. Díez Co nell,44 A. Dimi ie ska,18
J. Ding elde ,24 F. Di us,35 F. Djama,99 T. Djoba a,156b J. I. Dju sland,59a M. A. B. Do Vale,78c M. Dob e,27b D. Dodswo h,26
C. Doglioni,94 J. Dolejsi,139 Z. Dolezal,139 M. Donadelli,78d J. Donini,37 A. D’ono io,90 M. D’Ono io,88 J. Dopke,141
A. Do ia,67a M. T. Do a,86 A. T. Doyle,55 E. D echsle ,51 E. D eye ,149 T. D eye ,51 Y. Du,58b J. Dua e-Campde os,158
F. Dubinin,108 M. Dubo sky,28a A. Dub euil,52 E. Ducho ni,177 G. Duckeck,112 A. Ducou hial,132 O. A. Ducu,107,pD. Duda,113
A. Duda e ,35 A. C. Dudde ,97 E. M. Du ield,18 L. Du lo ,128 M. Düh ssen,35 C. Dülsen,179 M. Dumancic,177
A. E. Dumi iu,27b,qA. K. Duncan,55 M. Dun o d,59a A. Dupe in,99 H. Du an Yildiz,4a M. Dü en,54 A. Du glish ili,156b
D. Duschinge ,46 B. Du a,44 D. Du njak,1M. Dyndal,44 S. Dysch,98 B. S. Dziedzic,82 C. Ecka d ,44 K. M. Ecke ,113
R. C. Edga ,103 T. Ei e ,35 G. Eigen,17 K. Einsweile ,18 T. Ekelo ,169 M. El Kacimi,34c R. El Kossei i,99 V. Ellajosyula,99
024908-24
MEASUREMENT OF JET FRAGMENTATION IN Pb+Pb AND … PHYSICAL REVIEW C 98, 024908 (2018)
M. Elle ,169 F. Ellinghaus,179 A. A. Ellio ,90 N. Ellis,35 J. Elmsheuse ,29 M. Elsing,35 D. Emeliyano ,141 Y. Ena i,160
J. S. Ennis,175 M. B. Epland,47 J. E dmann,45 A. E edi a o,20 S. E ede,170 M. Escalie ,128 C. Escoba ,171 O. Es ada Pas o ,171
A. I. E ien e,142 E. E zion,158 H. E ans,63 A. Ezhilo ,134 M. Ezzi,34e F. Fabb i,55 L. Fabb i,23b,23a V. Fabiani,117 G. Facini,92
R. M. Faisca Rod igues Pe ei a,136a R. M. Fakh u dino ,140 S. Falciano,70a P. J. Falke,5S. Falke,5J. Fal o a,139 Y. Fang,15a
M. Fan i,66a,66b A. Fa bin,8A. Fa illa,72a E. M. Fa ina,68a,68b T. Fa ooque,104 S. Fa ell,18 S. M. Fa ing on,175 P. Fa houa ,35
F. Fassi,34e P. Fassnach ,35 D. Fassoulio is,9M. Faucci Giannelli,48 A. Fa a e o,53b,53a W. J. Fawce ,52 L. Faya d,128
O. L. Fedin,134, W. Fedo ko,172 M. Feicke ,41 S. Feigl,130 L. Feligioni,99 C. Feng,58b E. J. Feng,35 M. Feng,47 M. J. Fen on,55
A. B. Fenyuk,140 L. Fe emenga,8J. Fe ando,44 A. Fe a i,169 P. Fe a i,118 R. Fe a i,68a D. E. Fe ei a de Lima,59b A. Fe e ,171
D. Fe e e,52 C. Fe e i,103 F. Fiedle ,97 A. Filipˇciˇc,89 F. Fil hau ,117 K. D. Finelli,25 M. C. N. Fiolhais,136a,136c,sL. Fio ini,171
C. Fische ,14 W. C. Fishe ,104 N. Flaschel,44 I. Fleck,148 P. Fleischmann,103 R. R. M. Fle che ,133 T. Flick,179 B. M. Flie l,112
L. M. Flo es,133 L. R. Flo es Cas illo,61a N. Fomin,17 G. T. Fo colin,98 A. Fo mica,142 F. A. Fö s e ,14 A. C. Fo i,98
A. G. Fos e ,21 D. Fou nie ,128 H. Fox,87 S. F acchia,146 P. F anca illa,69a,69b M. F anchini,23b,23a S. F anchino,59a D. F ancis,35
L. F anconi,130 M. F anklin,57 M. F a e,168 M. F a e nali,68a,68b D. F eebo n,92 S. M. F essa d-Ba aneanu,35 B. F eund,107
W. S. F eund,78b D. F oide aux,35 J. A. F os ,131 C. Fukunaga,161 E. Fullana To eg osa,171 T. Fusayasu,114 J. Fus e ,171
O. Gabizon,157 A. Gab ielli,23b,23a A. Gab ielli,18 G. P. Gach,81a S. Gada sch,52 P. Gadow,113 G. Gaglia di,53b,53a
L. G. Gagnon,107 C. Galea,27b B. Galha do,136a,136c E. J. Gallas,131 B. J. Gallop,141 P. Gallus,138 G. Gals e ,39
R. Gamboa Goni,90 K. K. Gan,122 S. Ganguly,177 Y. Gao,88 Y. S. Gao,150,gC. Ga cía,171 J. E. Ga cía Na a o,171
J. A. Ga cía Pascual,15a M. Ga cia-Sci e es,18 R. W. Ga dne ,36 N. Ga elli,150 V. Ga onne,130 K. Gasniko a,44
A. Gaudiello,53b,53a G. Gaudio,68a I. L. Ga ilenko,108 A. Ga ilyuk,109 C. Gay,172 G. Gaycken,24 E. N. Gazis,10 C. N. P. Gee,141
J. Geisen,51 M. Geisen,97 M. P. Geisle ,59a K. Gelle s ed ,43a,43b C. Gemme,53b M. H. Genes ,56 C. Geng,103 S. Gen ile,70a,70b
C. Gen sos,159 S. Geo ge,91 D. Ge baudo,14 G. Gessne ,45 S. Ghasemi,148 M. Ghasemi Bos anabad,173 M. Ghneima ,24
B. Giacobbe,23b S. Giagu,70a,70b N. Giangiacomi,23b,23a P. Gianne i,69a A. Giannini,67a,67b S. M. Gibson,91 M. Gignac,143
D. Gillbe g,33 G. Gilles,179 D. M. Ging ich,3,eM. P. Gio dani,64a,64c F. M. Gio gi,23b P. F. Gi aud,142 P. Gi omini,57
G. Giuglia elli,64a,64c D. Giugni,66a F. Giuli,131 M. Giulini,59b S. Gkai a zis,159 I. Gkialas,9, E. L. Gkougkousis,14
P. Gkoun oumis,10 L. K. Gladilin,111 C. Glasman,96 J. Gla ze ,14 P. C. F. Glayshe ,44 A. Glazo ,44 M. Gobli sch-Kolb,26
J. Godlewski,82 S. Gold a b,102 T. Golling,52 D. Golubko ,140 A. Gomes,136a,136b,136d R. Goncal es Gama,78a R. Gonçalo,136a
G. Gonella,50 L. Gonella,21 A. Gongadze,77 F. Gonnella,21 J. L. Gonski,57 S. González de la Hoz,171 S. Gonzalez-Se illa,52
L. Goossens,35 P. A. Go bouno ,109 H. A. Go don,29 B. Go ini,35 E. Go ini,65a,65b A. Go išek,89 A. T. Goshaw,47 C. Gössling,45
M. I. Gos kin,77 C. A. Go a do,24 C. R. Goude ,128 D. Goujdami,34c A. G. Goussiou,145 N. Go ende ,32b,uC. Goy,5
E. Gozani,157 I. G abowska-Bold,81a P. O. J. G adin,169 E. C. G aham,88 J. G amling,168 E. G ams ad,130 S. G ancagnolo,19
V. G a che ,134 P. M. G a ila,27 C. G ay,55 H. M. G ay,18 Z. D. G eenwood,93, C. G e e,24 K. G ege sen,92 I. M. G ego ,44
P. G enie ,150 K. G e so ,44 J. G i i hs,8A. A. G illo,143 K. G imm,150 S. G ins ein,14,wPh. G is,37 J.-F. G i az,128 S. G oh,97
E. G oss,177 J. G osse-Kne e ,51 G. C. G ossi,93 Z. J. G ou ,92 C. G ud,103 A. G umme ,116 L. Guan,103 W. Guan,178
J. Guen he ,35 A. Gue guichon,128 F. Guescini,165a D. Gues ,168 R. Gugel,50 B. Gui,122 T. Guillemin,5S. Guindon,35 U. Gul,55
C. Gumpe ,35 J. Guo,58c W. Guo,103 Y. Guo,58a,xZ. Guo,99 R. Gup a,41 S. Gu buz,12c G. Gus a ino,124 B. J. Gu elman,157
P. Gu ie ez,124 C. Gu schow,92 C. Guyo ,142 M. P. Guzik,81a C. Gwenlan,131 C. B. Gwilliam,88 A. Haas,121 C. Habe ,18
H. K. Hada and,8N. Haddad,34e A. Hade ,58a S. Hageböck,24 M. Hagiha a,166 H. Hakobyan,181,aM. Haleem,174 J. Haley,125
G. Halladjian,104 G. D. Hallewell,99 K. Hamache ,179 P. Hamal,126 K. Hamano,173 A. Hamil on,32a G. N. Hami y,146
K. Han,58a,yL. Han,58a S. Han,15d K. Hanagaki,79,zM. Hance,143 D. M. Handl,112 B. Haney,133 R. Hankache,132 P. Hanke,59a
E. Hansen,94 J. B. Hansen,39 J. D. Hansen,39 M. C. Hansen,24 P. H. Hansen,39 K. Ha a,166 A. S. Ha d,178 T. Ha enbe g,179
S. Ha kusha,105 P. F. Ha ison,175 N. M. Ha mann,112 Y. Hasegawa,147 A. Hasib,48 S. Hassani,142 S. Haug,20 R. Hause ,104
L. Hauswald,46 L. B. Ha ene ,38 M. Ha anek,138 C. M. Hawkes,21 R. J. Hawkings,35 D. Hayden,104 C. Hayes,152 C. P. Hays,131
J. M. Hays,90 H. S. Haywa d,88 S. J. Haywood,141 M. P. Hea h,48 V. Hedbe g,94 L. Heelan,8S. Hee ,24 K. K. Heidegge ,50
J. Heilman,33 S. Heim,44 T. Heim,18 B. Heinemann,44,aa J. J. Hein ich,112 L. Hein ich,121 C. Heinz,54 J. Hejbal,137 L. Hela y,35
A. Held,172 S. Hellesund,130 S. Hellman,43a,43b C. Helsens,35 R. C. W. Hende son,87 Y. Heng,178 S. Henkelmann,172
A. M. Hen iques Co eia,35 G. H. He be ,19 H. He de,26 V. He ge ,174 Y. He nández Jiménez,32c H. He ,97 M. G. He mann,112
G. He en,50 R. He enbe ge ,112 L. He as,35 T. C. He wig,133 G. G. Heske h,92 N. P. Hessey,165a J. W. He he ly,41
S. Higashino,79 E. Higón-Rod iguez,171 K. Hildeb and,36 E. Hill,173 J. C. Hill,31 K. K. Hill,29 K. H. Hille ,44 S. J. Hillie ,21
M. Hils,46 I. Hinchli e,18 M. Hi ose,129 D. Hi schbuehl,179 B. Hi i,89 O. Hladik,137 D. R. Hlaluku,32c X. Hoad,48 J. Hobbs,152
N. Hod,165a M. C. Hodgkinson,146 A. Hoecke ,35 M. R. Hoe e kamp,116 F. Hoenig,112 D. Hohn,24 D. Hoho ,128 T. R. Holmes,36
M. Holzbock,112 M. Homann,45 S. Honda,166 T. Honda,79 T. M. Hong,135 A. Hönle,113 B. H. Hoobe man,170 W. H. Hopkins,127
Y. Ho ii,115 P. Ho n,46 A. J. Ho on,149 L. A. Ho yn,36 J-Y. Hos achy,56 A. Hos iuc,145 S. Hou,155 A. Hoummada,34a
J. Howa h,98 J. Hoya,86 M. H abo sky,126 J. H dinka,35 I. H is o a,19 J. H i nac,128 A. H yne ich,106 T. H yn’o a,5P. J. Hsu,62
S.-C. Hsu,145 Q. Hu,29 S. Hu,58c Y. Huang,15a Z. Hubacek,138 F. Hubau ,99 M. Huebne ,24 F. Huegging,24 T. B. Hu man,131
E. W. Hughes,38 M. Huh inen,35 R. F. H. Hun e ,33 P. Huo,152 A. M. Hupe,33 N. Huseyno ,77,dJ. Hus on,104 J. Hu h,57
R. Hyneman,103 G. Iacobucci,52 G. Iako idis,29 I. Ib agimo ,148 L. Iconomidou-Faya d,128 Z. Id issi,34e P. Iengo,35 R. Ignazzi,39
O. Igonkina,118,ab R. Iguchi,160 T. Iizawa,52 Y. Ikegami,79 M. Ikeno,79 D. Iliadis,159 N. Ilic,150 F. Il zsche,46 G. In ozzi,68a,68b
M. Iodice,72a K. Io danidou,38 V. Ippoli o,70a,70b M. F. Isacson,169 N. Ishijima,129 M. Ishino,160 M. Ishi suka,162 W. Islam,125
024908-25
M. AABOUD e al. PHYSICAL REVIEW C 98, 024908 (2018)
76Depa men o Physics and As onomy, Iowa S a e Uni e si y, Ames, Iowa, USA
77Join Ins i u e o Nuclea Resea ch, Dubna, Russia
78aDepa amen o de Engenha ia Elé ica, Uni e sidade Fede al de Juiz de Fo a (UFJF), Juiz de Fo a, B azil
78bUni e sidade Fede al do Rio De Janei o COPPE/EE/IF, Rio de Janei o, B azil
78cUni e sidade Fede al de São João del Rei (UFSJ), São João del Rei, B azil
78dIns i u o de Física, Uni e sidade de São Paulo, São Paulo, B azil
79KEK, High Ene gy Accele a o Resea ch O ganiza ion, Tsukuba, Japan
80G adua e School o Science, Kobe Uni e si y, Kobe, Japan
81aAGH Uni e si y o Science and Technology, Facul y o Physics and Applied Compu e Science, K akow
81bMa ian Smoluchowski Ins i u e o Physics, Jagiellonian Uni e si y, K akow, Poland
82Ins i u e o Nuclea Physics Polish Academy o Sciences, K akow, Poland
83Facul y o Science, Kyo o Uni e si y, Kyo o, Japan
84Kyo o Uni e si y o Educa ion, Kyo o, Japan
85Resea ch Cen e o Ad anced Pa icle Physics and Depa men o Physics, Kyushu Uni e si y, Fukuoka, Japan
86Ins i u o de Física La Pla a, Uni e sidad Nacional de La Pla a and CONICET, La Pla a, A gen ina
87Physics Depa men , Lancas e Uni e si y, Lancas e , Uni ed Kingdom
88Oli e Lodge Labo a o y, Uni e si y o Li e pool, Li e pool, Uni ed Kingdom
89Depa men o Expe imen al Pa icle Physics, Jože S e an Ins i u e and Depa men o Physics,
Uni e si y o Ljubljana, Ljubljana, Slo enia
90School o Physics and As onomy, Queen Ma y Uni e si y o London, London, Uni ed Kingdom
91Depa men o Physics, Royal Holloway Uni e si y o London, Egham, Uni ed Kingdom
92Depa men o Physics and As onomy, Uni e si y College London, London, Uni ed Kingdom
93Louisiana Tech Uni e si y, Rus on, Louisiana, USA
94Fysiska ins i u ionen, Lunds Uni e si e , Lund, Sweden
95Cen e de Calcul de l’Ins i u Na ional de Physique Nucléai e e de Physique des Pa icules (IN2P3), Villeu banne, F ance
96Depa amen o de Física Teo ica C-15 and CIAFF, Uni e sidad Au ónoma de Mad id, Mad id, Spain
97Ins i u ü Physik, Uni e si ä Mainz, Mainz, Ge many
98School o Physics and As onomy, Uni e si y o Manches e , Manches e , Uni ed Kingdom
99CPPM, Aix-Ma seille Uni e si é, CNRS/IN2P3, Ma seille, F ance
100Depa men o Physics, Uni e si y o Massachuse s, Amhe s , Massachuse s, USA
101Depa men o Physics, McGill Uni e si y, Mon eal, Quebec, Canada
102School o Physics, Uni e si y o Melbou ne, Vic o ia, Aus alia
103Depa men o Physics, Uni e si y o Michigan, Ann A bo , Michigan, USA
104Depa men o Physics and As onomy, Michigan S a e Uni e si y, Eas Lansing, Michigan, USA
105B.I. S epano Ins i u e o Physics, Na ional Academy o Sciences o Bela us, Minsk, Bela us
106Resea ch Ins i u e o Nuclea P oblems o Byelo ussian S a e Uni e si y, Minsk, Bela us
107G oup o Pa icle Physics, Uni e si y o Mon eal, Mon eal, Quebec, Canada
108P.N. Lebede Physical Ins i u e o he Russian Academy o Sciences, Moscow, Russia
109Ins i u e o Theo e ical and Expe imen al Physics (ITEP), Moscow, Russia
110Na ional Resea ch Nuclea Uni e si y MEPhI, Moscow, Russia
111D.V. Skobel syn Ins i u e o Nuclea Physics, M.V. Lomonoso Moscow S a e Uni e si y, Moscow, Russia
112Fakul ä ü Physik, Ludwig-Maximilians-Uni e si ä München, München, Ge many
113Max-Planck-Ins i u ü Physik (We ne -Heisenbe g-Ins i u ), München, Ge many
114Nagasaki Ins i u e o Applied Science, Nagasaki, Japan
115G adua e School o Science and Kobayashi-Maskawa Ins i u e, Nagoya Uni e si y, Nagoya, Japan
116Depa men o Physics and As onomy, Uni e si y o New Mexico, Albuque que, New Mexico, USA
117Ins i u e o Ma hema ics, As ophysics and Pa icle Physics, Radboud Uni e si y Nijmegen/Nikhe , Nijmegen, Ne he lands
118Nikhe Na ional Ins i u e o Suba omic Physics and Uni e si y o Ams e dam, Ams e dam, Ne he lands
119Depa men o Physics, No he n Illinois Uni e si y, DeKalb, Illinois, USA
120aBudke Ins i u e o Nuclea Physics, SB RAS, No osibi sk
120bNo osibi sk S a e Uni e si y No osibi sk, Russia
121Depa men o Physics, New Yo k Uni e si y, New Yo k, New Yo k, USA
122Ohio S a e Uni e si y, Columbus, Ohio, USA
123Facul y o Science, Okayama Uni e si y, Okayama, Japan
124Home L. Dodge Depa men o Physics and As onomy, Uni e si y o Oklahoma, No man, Oklahoma, USA
125Depa men o Physics, Oklahoma S a e Uni e si y, S illwa e , Oklahoma, USA
126Palacký Uni e si y, RCPTM, Join Labo a o y o Op ics, Olomouc, Czech Republic
127Cen e o High Ene gy Physics, Uni e si y o O egon, Eugene, O egon, USA
128LAL, Uni e si é Pa is-Sud, CNRS/IN2P3, Uni e si é Pa is-Saclay, O say, F ance
024908-32

MEASUREMENT OF JET FRAGMENTATION IN Pb+Pb AND … PHYSICAL REVIEW C 98, 024908 (2018)
129G adua e School o Science, Osaka Uni e si y, Osaka, Japan
130Depa men o Physics, Uni e si y o Oslo, Oslo, No way
131Depa men o Physics, Ox o d Uni e si y, Ox o d, Uni ed Kingdom
132LPNHE, So bonne Uni e si é, Pa is Dide o So bonne Pa is Ci é, CNRS/IN2P3, Pa is, F ance
133Depa men o Physics, Uni e si y o Pennsyl ania, Philadelphia, Pennsyl ania, USA
134Kons an ino Nuclea Physics Ins i u e o Na ional Resea ch Cen e “Ku cha o Ins i u e,” PNPI, S . Pe e sbu g, Russia
135Depa men o Physics and As onomy, Uni e si y o Pi sbu gh, Pi sbu gh, Pennsyl ania, USA
136aLabo a ó io de Ins umen ação e Física Expe imen al de Pa ículas - LIP, Lisboa, Po ugal
136bDepa amen o de Física, Faculdade de Ciências, Uni e sidade de Lisboa, Lisboa, Po ugal
136cDepa amen o de Física, Uni e sidade de Coimb a, Coimb a, Po ugal
136dCen o de Física Nuclea da Uni e sidade de Lisboa, Lisboa, Po ugal
136eDepa amen o de Física, Uni e sidade do Minho, B aga, Po ugal
136 Depa amen o de Física Teo ica y del Cosmos, Uni e sidad de G anada, G anada, Spain
136gDep Física and CEFITEC o Faculdade de Ciências e Tecnologia, Uni e sidade No a de Lisboa, Capa ica, Po ugal
137Ins i u e o Physics, Academy o Sciences o he Czech Republic, P ague,Czech Republic
138Czech Technical Uni e si y in P ague, P ague, Czech Republic
139Cha les Uni e si y, Facul y o Ma hema ics and Physics, P ague, Czech Republic
140S a e Resea ch Cen e Ins i u e o High Ene gy Physics, NRC KI, P o ino, Russia
141Pa icle Physics Depa men , Ru he o d Apple on Labo a o y, Didco , Uni ed Kingdom
142IRFU, CEA, Uni e si é Pa is-Saclay, Gi -su -Y e e, F ance
143San a C uz Ins i u e o Pa icle Physics, Uni e si y o Cali o nia San a C uz, San a C uz, Cali o nia, USA
144aDepa amen o de Física, Pon i icia Uni e sidad Ca ólica de Chile, San iago, Chile
144bDepa amen o de Física, Uni e sidad Técnica Fede ico San a Ma ía, Valpa aíso, Chile
145Depa men o Physics, Uni e si y o Washing on, Sea le, Washing on, USA
146Depa men o Physics and As onomy, Uni e si y o She ield, She ield, Uni ed Kingdom
147Depa men o Physics, Shinshu Uni e si y, Nagano, Japan
148Depa men Physik, Uni e si ä Siegen, Siegen, Ge many
149Depa men o Physics, Simon F ase Uni e si y, Bu naby, B i ish Columbia, Canada
150SLAC Na ional Accele a o Labo a o y, S an o d, Cali o nia, USA
151Physics Depa men , Royal Ins i u e o Technology, S ockholm, Sweden
152Depa men s o Physics and As onomy, S ony B ook Uni e si y, S ony B ook, New Yo k, USA
153Depa men o Physics and As onomy, Uni e si y o Sussex, B igh on, Uni ed Kingdom
154School o Physics, Uni e si y o Sydney, Sydney, Aus alia
155Ins i u e o Physics, Academia Sinica, Taipei, Taiwan
156aE. And onikash ili Ins i u e o Physics, I . Ja akhish ili Tbilisi S a e Uni e si y, Tbilisi, Geo gia
156bHigh Ene gy Physics Ins i u e, Tbilisi S a e Uni e si y, Tbilisi, Geo gia
157Depa men o Physics, Technion, Is ael Ins i u e o Technology, Hai a, Is ael
158Raymond and Be e ly Sackle School o Physics and As onomy, Tel A i Uni e si y, Tel A i , Is ael
159Depa men o Physics, A is o le Uni e si y o Thessaloniki, Thessaloniki, G eece
160In e na ional Cen e o Elemen a y Pa icle Physics and Depa men o Physics, Uni e si y o Tokyo, Tokyo, Japan
161G adua e School o Science and Technology, Tokyo Me opoli an Uni e si y, Tokyo, Japan
162Depa men o Physics, Tokyo Ins i u e o Technology, Tokyo, Japan
163Tomsk S a e Uni e si y, Tomsk, Russia
164Depa men o Physics, Uni e si y o To on o, To on o, On a io, Canada
165aTRIUMF, Vancou e BC
165bDepa men o Physics and As onomy, Yo k Uni e si y, To on o, On a io, Canada
166Di ision o Physics and Tomonaga Cen e o he His o y o he Uni e se, Facul y o Pu e and Applied Sciences,
Uni e si y o Tsukuba, Tsukuba Japan
167Depa men o Physics and As onomy, Tu s Uni e si y, Med o d, Massachuse s, USA
168Depa men o Physics and As onomy, Uni e si y o Cali o nia I ine, I ine, Cali o nia, USA
169Depa men o Physics and As onomy, Uni e si y o Uppsala, Uppsala, Sweden
170Depa men o Physics, Uni e si y o Illinois, U bana, Illinois, USA
171Ins i u o de Física Co puscula (IFIC), Cen o Mix o Uni e sidad de Valencia - CSIC, Valencia, Spain
172Depa men o Physics, Uni e si y o B i ish Columbia, Vancou e , B i ish Columbia, Canada
173Depa men o Physics and As onomy, Uni e si y o Vic o ia, Vic o ia, B i ish Columbia, Canada
174Fakul ä ü Physik und As onomie, Julius-Maximilians-Uni e si ä Wü zbu g, Wü zbu g, Ge many
175Depa men o Physics, Uni e si y o Wa wick, Co en y, Uni ed Kingdom
176Waseda Uni e si y, Tokyo, Japan
177Depa men o Pa icle Physics, Weizmann Ins i u e o Science, Reho o , Is ael
024908-33
M. AABOUD e al. PHYSICAL REVIEW C 98, 024908 (2018)
178Depa men o Physics, Uni e si y o Wisconsin, Madison, Wisconsin, USA
179Fakul ä ü Ma hema ik und Na u wissenscha en, Fachg uppe Physik, Be gische Uni e si ä Wuppe al, Wuppe al, Ge many
180Depa men o Physics, Yale Uni e si y, New Ha en, Connec icu , USA
181Ye e an Physics Ins i u e, Ye e an, A menia
aDeceased.
bAlso a Depa men o Physics, King’s College London, London, Uni ed Kingdom.
cAlso a Is anbul Uni e si y, Dep . o Physics, Is anbul, Tu key.
dAlso a Ins i u e o Physics, Aze baijan Academy o Sciences, Baku, Aze baijan.
eAlso a TRIUMF, Vancou e , BC, Canada.
Also a Depa men o Physics and As onomy, Uni e si y o Louis ille, Louis ille, KY, USA.
gAlso a Depa men o Physics, Cali o nia S a e Uni e si y, F esno, CA, USA.
hAlso a Depa men o Physics, Uni e si y o F ibou g, F ibou g, Swi ze land.
iAlso a II. Physikalisches Ins i u , Geo g-Augus -Uni e si ä Gö ingen, Gö ingen, Ge many.
jAlso a Depa amen de Fisica de la Uni e si a Au onoma de Ba celona, Ba celona, Spain.
kAlso a Tomsk S a e Uni e si y, Tomsk, and Moscow Ins i u e o Physics and Technology S a e Uni e si y, Dolgop udny, Russia.
lAlso a The Collabo a i e Inno a ion Cen e o Quan um Ma e (CICQM), Beijing, China.
mAlso a Uni e si a di Napoli Pa henope, Napoli, I aly.
nAlso a Ins i u e o Pa icle Physics (IPP), Vic o ia, BC, Canada.
oAlso a Dipa imen o di Fisica E. Fe mi, Uni e si à di Pisa, Pisa, I aly.
pAlso a Ho ia Hulubei Na ional Ins i u e o Physics and Nuclea Enginee ing, Bucha es , Romania.
qAlso a CPPM, Aix-Ma seille Uni e si é, CNRS/IN2P3, Ma seille, F ance.
Also a Depa men o Physics, S . Pe e sbu g S a e Poly echnical Uni e si y, S . Pe e sbu g, Russia.
sAlso a Bo ough o Manha an Communi y College, Ci y Uni e si y o New Yo k, NY, USA.
Also a Depa men o Financial and Managemen Enginee ing, Uni e si y o he Aegean, Chios, G eece.
uAlso a Cen e o High Pe o mance Compu ing, CSIR Campus, Rosebank, Cape Town, Sou h A ica.
Also a Louisiana Tech Uni e si y, Rus on, LA, USA.
wAlso a Ins i ucio Ca alana de Rece ca i Es udis A anca s, ICREA, Ba celona, Spain.
xAlso a Depa men o Physics, Uni e si y o Michigan, Ann A bo , MI, USA.
yAlso a LAL, Uni e si é Pa is-Sud, CNRS/IN2P3, Uni e si é Pa is-Saclay, O say, F ance.
zAlso a G adua e School o Science, Osaka Uni e si y, Osaka, Japan.
aaAlso a Physikalisches Ins i u , Albe -Ludwigs-Uni e si ä F eibu g, F eibu g, Ge many.
abAlso a Ins i u e o Ma hema ics, As ophysics and Pa icle Physics, Radboud Uni e si y Nijmegen/Nikhe , Nijmegen, Ne he lands.
acAlso a Nea Eas Uni e si y, Nicosia, No h Cyp us, Me sin, Tu key.
adAlso a Ins i u e o Theo e ical Physics, Ilia S a e Uni e si y, Tbilisi, Geo gia.
aeAlso a CERN, Gene a, Swi ze land.
a Also a Manha an College, New Yo k, NY, USA.
agAlso a Hellenic Open Uni e si y, Pa as, G eece.
ahAlso a The Ci y College o New Yo k, New Yo k, NY, USA.
aiAlso a Depa amen o de Física Teo ica y del Cosmos, Uni e sidad de G anada, G anada, Spain.
ajAlso a Depa men o Physics, Cali o nia S a e Uni e si y, Sac amen o, CA, USA.
akAlso a Moscow Ins i u e o Physics and Technology S a e Uni e si y, Dolgop udny, Russia.
alAlso a Dépa emen de Physique Nucléai e e Co pusculai e, Uni e si é de Genè e, Genè e, Swi ze land.
amAlso a Depa men o Physics and As onomy, Uni e si y o She ield, She ield, Uni ed Kingdom.
anAlso a School o Physics, Sun Ya -sen Uni e si y, Guangzhou, China.
aoAlso a Depa men o Applied Physics and As onomy, Uni e si y o Sha jah, Sha jah, Uni ed A ab Emi a es.
apAlso a Ins i u ü Expe imen alphysik, Uni e si ä Hambu g, Hambu g, Ge many.
aqAlso a Na ional Resea ch Nuclea Uni e si y MEPhI, Moscow, Russia.
a Also a Ins i u e o Pa icle and Nuclea Physics, Wigne Resea ch Cen e o Physics, Budapes , Hunga y.
asAlso a Gi esun Uni e si y, Facul y o Enginee ing, Gi esun, Tu key.
a Also a Depa men o Physics, Nanjing Uni e si y, Nanjing, China.
auAlso a Ins i u e o Physics, Academia Sinica, Taipei, Taiwan.
024908-34