Observation of the decay Λ 0b → ψ(2S)pπ−

JHEP08(2018)131
Published o SISSA by Sp inge
Recei ed:June 22, 2018
Accep ed:Augus 9, 2018
Published:Augus 21, 2018
Obse a ion o he decay Λ0
b→ψ(2S)pπ−
The LHCb collabo a ion
E-mail: [email p o ec ed]
Abs ac : The Cabibbo-supp essed decay Λ0
b→ψ(2S)pπ−is obse ed o he i s ime
using a da a sample collec ed by he LHCb expe imen in p o on-p o on collisions co -
esponding o 1.0, 2.0 and 1.9 b−1o in eg a ed luminosi y a cen e-o -mass ene gies o
7, 8 and 13 TeV, espec i ely. The ψ(2S) mesons a e econs uc ed in he µ+µ− inal
s a e. The b anching ac ion wi h espec o ha o he Λ0
b→ψ(2S)pK−decay mode is
measu ed o be BΛ0
b→ψ(2S)pπ−
BΛ0
b→ψ(2S)pK−= (11.4±1.3±0.2)% ,
whe e he i s unce ain y is s a is ical and he second is sys ema ic. The ψ(2S)p and
ψ(2S)π−mass spec a a e in es iga ed and no e idence o exo ic esonances is ound.
Keywo ds: B physics, Fla o physics, Had on-Had on sca e ing (expe imen s),
Spec oscopy
A Xi eP in : 1806.08084
Open Access, Copy igh CERN,
o he bene i o he LHCb Collabo a ion.
A icle unded by SCOAP3.
h ps://doi.o g/10.1007/JHEP08(2018)131
JHEP08(2018)131
Con en s
1 In oduc ion 1
2 De ec o and simula ion 2
3 E en selec ion 3
4 Signal yields and e iciencies 4
5 Sys ema ic unce ain ies 6
6 Resul s and summa y 7
The LHCb collabo a ion 12
1 In oduc ion
The Λ0
bba yon is he isospin-single g ound s a e o a bound sys em o a beau y qua k
and wo ligh qua ks. The high p oduc ion a e o b qua ks a he La ge Had on Collide
(LHC) [1–5], along wi h he excellen mass esolu ion and had on-iden i ica ion capabil-
i ies o he LHCb de ec o , gi e access o a a ie y o decay channels o he Λ0
bba yon,
including mul ibody, a e, cha mless and semilep onic decays [6–25]. The high signal yield
o he Λ0
b→J/ψpK−decay [15] acili a ed a p ecise measu emen o he Λ0
bli e ime [26],
while he ela i ely low ene gy eleased in he Λ0
b→ψ(2S)pK−and Λ0
b→χcpK−decays
allowed o p ecise measu emen s o he Λ0
bmass [16,22]. A six-dimensional ampli ude
analysis o he Λ0
b→J/ψpK−decay esul ed in he obse a ion o he Pc(4380)+and
Pc(4450)+pen aqua k s a es decaying in o he J/ψp inal s a e [27]. La e , hese s a es
we e con i med using a model-independen echnique [28]. Subsequen ly, an analysis
o Cabibbo-supp essed Λ0
b→J/ψpπ−decays ound e idence o con ibu ions om
he Pc(4380)+and Pc(4450)+pen aqua ks and om he Zc(4200)− e aqua k [29].
The i s obse a ion o Λ0
bdecays o he exci ed cha monium s a e ψ(2S) was made
in he Λ0
b→ψ(2S)Λ decay mode by he ATLAS collabo a ion [30]. La e , he decay
Λ0
b→ψ(2S)pK−was obse ed by he LHCb collabo a ion [16]. The Cabibbo-supp essed
analogue o he la e decay, Λ0
b→ψ(2S)pπ−, is o pa icula in e es because o possible
con ibu ions om exo ic s a es in bo h he ψ(2S)p sys em, simila o he Pc(4380)+and
Pc(4450)+pen aqua k s a es, and in he ψ(2S)π−sys em, analogous o he cha ged cha -
monium-like s a e Zc(4430)−s udied in de ail by he Belle and LHCb collabo a ions in
B→ψ(2S)π−K decays [31–35]. Depending on he na u e o a p oposed exo ic s a e, i s
coupling wi h he ψ(2S) meson can be la ge han wi h he J/ψmeson. Fo example,
– 1 –
JHEP08(2018)131
he decay a e o he X(3872) pa icle o he ψ(2S)γ inal s a e was ound o exceed
he co esponding decay a e o he J/ψγ inal s a e [36,37].
This pape epo s he i s obse a ion o he decay Λ0
b→ψ(2S)pπ−using a da a
sample collec ed by he LHCb expe imen in p o on-p o on collisions co esponding o 1.0,
2.0 and 1.9 b−1o in eg a ed luminosi y a cen e-o -mass ene gies o 7, 8 and 13 TeV,
espec i ely. A measu emen is made o he Λ0
b→ψ(2S)pπ−b anching ac ion ela i e o
ha o he Cabibbo- a ou ed decay Λ0
b→ψ(2S)pK−,
Rπ/K≡BΛ0
b→ψ(2S)pπ−
BΛ0
b→ψ(2S)pK−,(1.1)
whe e he ψ(2S) mesons a e econs uc ed in he µ+µ− inal s a e. Th oughou his pape
he inclusion o cha ge-conjuga ed p ocesses is implied.
2 De ec o and simula ion
The LHCb de ec o [38,39] is a single-a m o wa d spec ome e co e ing he pseudo-
apidi y ange 2 < η < 5, designed o he s udy o pa icles con aining b o c qua ks.
The de ec o includes a high-p ecision acking sys em consis ing o a silicon-s ip e ex
de ec o su ounding he pp in e ac ion egion, a la ge-a ea silicon-s ip de ec o loca ed
ups eam o a dipole magne wi h a bending powe o abou 4 Tm, and h ee s a ions o
silicon-s ip de ec o s and s aw d i ubes placed downs eam o he magne . The ack-
ing sys em p o ides a measu emen o he momen um o cha ged pa icles wi h a ela i e
unce ain y ha a ies om 0.5% a low momen um o 1.0% a 200 GeV/c. The minimum
dis ance o a ack o a p ima y e ex (PV), he impac pa ame e (IP), is measu ed wi h
a esolu ion o (15 + 29/pT)µm, whe e pTis he componen o he momen um ans e se
o he beam, in GeV/c. Di e en ypes o cha ged had ons a e dis inguished using in o ma-
ion om wo ing-imaging Che enko de ec o s (RICH). Pho ons, elec ons and had ons
a e iden i ied by a calo ime e sys em consis ing o scin illa ing-pad and p eshowe de ec-
o s, an elec omagne ic calo ime e and a had onic calo ime e . Muons a e iden i ied by
a sys em composed o al e na ing laye s o i on and mul iwi e p opo ional chambe s.
The online e en selec ion is pe o med by a igge [40], which consis s o a ha dwa e
s age, based on in o ma ion om he calo ime e and muon sys ems, ollowed by a so wa e
s age, which applies a ull e en econs uc ion. The ha dwa e igge selec s muon candi-
da es wi h high ans e se momen um o dimuon candida es wi h high alue o he p oduc
o he pTo each muon. The subsequen so wa e igge is composed o wo s ages, he
i s o which pe o ms a pa ial e en econs uc ion, while ull e en econs uc ion is
done a he second s age. In he so wa e igge , each pai o opposi ely cha ged muons
o ming a good-quali y wo- ack e ex is equi ed o be signi ican ly displaced om all
PVs and he mass o he pai is equi ed o exceed 2.7 GeV/c2.
The echniques used in his analysis a e alida ed using simula ed e en s. In he simula-
ion, pp collisions a e gene a ed using Py hia [41] wi h a speci ic LHCb con igu a ion [42].
Decays o had onic pa icles a e desc ibed by E Gen [43], in which inal-s a e adia ion
– 2 –
JHEP08(2018)131
is gene a ed using Pho os [44]. The in e ac ion o he gene a ed pa icles wi h he de-
ec o , and i s esponse, a e implemen ed using he Gean 4 oolki [45,46] as desc ibed
in e . [47].
3 E en selec ion
The signal Λ0
b→ψ(2S)pπ−and he no maliza ion Λ0
b→ψ(2S)pK−decays a e bo h econ-
s uc ed using he decay mode ψ(2S) →µ+µ−. Simila selec ion c i e ia, based on hose
used in e . [16], a e applied o bo h channels.
Muon, p o on, pion and kaon candida es a e iden i ied using combined in o ma ion
om he RICH, calo ime e and muon de ec o s. They a e equi ed o ha e a ans e se
momen um la ge han 550, 900, 500 and 200 MeV/c, espec i ely. To allow o an e icien
pa icle iden i ica ion, kaons and pions a e equi ed o ha e a momen um be ween 3.2 and
150 GeV/c, whils p o ons mus ha e a momen um be ween 10 and 150 GeV/c. To educe
he combina o ial backg ound due o pa icles p oduced in he pp in e ac ion, only acks
ha a e inconsis en wi h o igina ing om a PV a e used.
Pai s o opposi ely cha ged muons consis en wi h o igina ing om a common e ex
a e combined o o m ψ(2S) →µ+µ−candida es. The mass o he dimuon candida e is
equi ed o be be ween 3.67 and 3.70 GeV/c2, whe e he asymme ic mass ange a ound
he known ψ(2S) mass [48] is chosen o accoun o inal-s a e adia ion. The posi ion
o he econs uc ed dimuon e ex is equi ed o be inconsis en wi h ha o any o
he econs uc ed PVs.
To o m signal (no maliza ion) Λ0
bcandida es, he selec ed ψ(2S) candida es a e com-
bined wi h a p o on and a pion (kaon) o opposi e cha ges. Each Λ0
bcandida e is associa ed
wi h he PV wi h espec o which i has he smalles χ2
IP, whe e χ2
IP is de ined as he di -
e ence in he e ex- i χ2o a gi en PV econs uc ed wi h and wi hou he pa icle
unde conside a ion. To imp o e he Λ0
bmass esolu ion, a kinema ic i [49] is pe o med.
This i cons ains he ou cha ged inal-s a e pa icles o o m common e ex, he mass
o he µ+µ−combina ion o he known ψ(2S) mass and he Λ0
bcandida e o o igina e om
he associa ed PV. A good quali y o his i is equi ed o u he supp ess combina o ial
backg ound. In addi ion, he measu ed decay ime o he Λ0
bcandida e, calcula ed wi h
espec o he associa ed PV, is equi ed o be be ween 0.2 and 2.0 mm/c o supp ess poo ly
econs uc ed candida es and backg ound om pa icles o igina ing om he PV.
To supp ess c oss- eed om B0→ψ(2S)K+π−decays wi h he posi i ely cha ged
kaon (nega i ely cha ged pion) misiden i ied as a p o on (an ip o on) o he signal (no -
maliza ion) channel, a e o is applied on he Λ0
bcandida e mass ecalcula ed wi h a kaon
(pion) mass hypo hesis o he p o on. Any candida e wi h a ecalcula ed mass consis en
wi h he nominal B0mass is ejec ed. A simila e o is applied o supp ess c oss- eed
om B0
s→ψ(2S)K−K+decays wi h he posi i ely cha ged kaon misiden i ied as a p o on,
and addi ionally o he signal channel, he nega i ely cha ged kaon misiden i ied as a pion.
Finally, o supp ess c oss- eed om he Λ0
b→ψ(2S)Λ decay, ollowed by a Λ→pπ−decay,
candida es wi h a pπ−mass ha is consis en wi h he nominal Λ mass [48] a e ejec ed.
– 3 –
JHEP08(2018)131
5.6 5.65
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5.6 5.65
1
10
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3
10
Candida es/(5 MeV/c2)
Candida es/(2 MeV/c2)
mψ(2S)pπ−mψ(2S)pK−
GeV/c2 GeV/c2
LHCb LHCb
Λ0
b→ψ(2S)pπ−
backg ound
o al i
Λ0
b→ψ(2S)pK−
backg ound
o al i
qda a qda a
Figu e 1. Mass dis ibu ions o he (le ) Λ0
b→ψ(2S)pπ−and ( igh ) Λ0
b→ψ(2S)pK−candida es.
4 Signal yields and e iciencies
The mass dis ibu ions o he selec ed Λ0
b→ψ(2S)pπ−and Λ0
b→ψ(2S)pK−candida es
a e shown in igu e 1. The signal yields a e de e mined using unbinned ex ended maxi-
mum-likelihood i s o hese dis ibu ions. Fo each dis ibu ion he Λ0
bcomponen is de-
sc ibed by a modi ied Gaussian unc ion wi h powe -law ails on bo h sides [50,51]. The ail
pa ame e s a e ixed o alues ob ained om simula ion, and he peak posi ion and eso-
lu ion o he Gaussian unc ion a e ee o a y in he i . The combina o ial backg ound
componen is desc ibed by a mono onic second-o de polynomial unc ion wi h posi i e cu -
a u e. The esolu ion pa ame e s ob ained om he i s a e ound o be 5.23 ±0.55 MeV/c2
o he Λ0
b→ψ(2S)pπ−channel and 3.96 ±0.13 MeV/c2 o he Λ0
b→ψ(2S)pK−channel,
which a e in good ag eemen wi h expec a ions om simula ion. The signal yields a e
de e mined o be 121±13 and 806±29 o he Λ0
b→ψ(2S)pπ−and Λ0
b→ψ(2S)pK−decay
modes, espec i ely.
The esonance s uc u e o he Λ0
b→ψ(2S)pπ−decay is in es iga ed using he sPlo
echnique [52] o backg ound sub ac ion, wi h he econs uc ed ψ(2S)pπ−mass as
he disc imina ing a iable. The backg ound-sub ac ed mass dis ibu ions o ψ(2S)p,
ψ(2S)π−and pπ−combina ions a e shown in igu e 2, along wi h hose ob ained om sim-
ula ed decays gene a ed acco ding o a phase-space model. The ψ(2S)p and ψ(2S)π−mass
dis ibu ions show no e idence o con ibu ions om exo ic s a es. The mass dis ibu ion
o he pπ−combina ion di e s om he phase-space model, indica ing possible con ibu-
ions om exci ed N0and ∆0s a es. Fu he s udies wi h a la ge da a sample will p o ide
a deepe insigh in o he unde lying s uc u e o he Λ0
b→ψ(2S)pπ−decay.
The a io o b anching ac ions Rπ/K, de ined in eq. (1.1), is measu ed as
Rπ/K=NΛ0
b→ψ(2S)pπ−
NΛ0
b→ψ(2S)pK−
εΛ0
b→ψ(2S)pK−
εΛ0
b→ψ(2S)pπ−
,(4.1)
– 4 –

JHEP08(2018)131
4.8 5 5.2 5.4
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30
35
40
4 4.2 4.4 4.6
0
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1.2 1.4 1.6 1.8
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40
NΛ0
b/(50 MeV/c2)
NΛ0
b/(50 MeV/c2)
NΛ0
b/(50 MeV/c2)
mψ(2S)p mψ(2S)π−mpπ−
GeV/c2 GeV/c2 GeV/c2
LHCb LHCb LHCb
simula ion simula ion simula ion
qda a qda a qda a
Figu e 2. Backg ound-sub ac ed mass dis ibu ions o he (le ) ψ(2S)p, (cen e) ψ(2S)π−and
( igh ) pπ+combina ions in he Λ0
b→ψ(2S)pπ−decay compa ed wi h dis ibu ions ob ained om
a phase-space simula ion.
whe e N ep esen s he measu ed yield and εdeno es he e iciency o he co esponding
decay. The e iciency is de ined as he p oduc o he geome ic accep ance and he de ec-
ion, econs uc ion, selec ion and igge e iciencies. The had on-iden i ica ion e icien-
cies as unc ions o kinema ics and he e en mul iplici y a e de e mined om da a us-
ing he ollowing calib a ion samples o low-backg ound decays: D∗+→D0(→K−π+)π+,
K0
S→π+π−and D+
s→φ(→K+K−)π+ o kaons and pions; and Λ →pπ−and
Λ+
c→pK+π− o p o ons [53,54]. The emaining e iciencies a e de e mined using sim-
ula ion. The pTand apidi y spec a and he li e ime o he Λ0
bba yons in simula ed
samples a e adjus ed o ma ch hose obse ed in a high-yield low-backg ound sample
o econs uc ed Λ0
b→J/ψpK−decays. The simula ed samples a e p oduced acco ding
o a phase-space decay model. The simula ed Λ0
b→ψ(2S)pK−decays a e co ec ed
o ep oduce he pK−mass and cos θpK−dis ibu ions obse ed in da a, whe e θpK−is
he helici y angle o he pK−sys em, de ined as he angle be ween he momen um ec-
o s o he kaon and Λ0
bba yon in he pK− es ame. To accoun o impe ec ions in
he simula ion o cha ged acks, co ec ions ob ained using da a-d i en echniques a e also
applied [55].
The e iciencies a e de e mined sepa a ely o each da a- aking pe iod and a e combined
acco ding o he co esponding luminosi y [56] o each pe iod and he known p oduc ion
c oss-sec ion o bb pai s in he LHCb accep ance [1–5]. The a io o he o al e iciency o
he no maliza ion channel o ha o he signal channel is de e mined o be
εΛ0
b
→ψ(2S)pK−
εΛ0
b
→ψ(2S)pπ−
= 0.761 ±0.004 ,(4.2)
whe e only he unce ain y ha a ises om he sizes o he simula ed samples is gi en.
Addi ional sou ces o unce ain y a e discussed in he ollowing sec ion. The kaon iden i-
ica ion e iciency, en e ing in o εΛ0
b
→ψ(2S)pK−, is he main ac o causing non-equali y o
he o al e iciencies o he signal and no maliza ion channels.
– 5 –
JHEP08(2018)131
5 Sys ema ic unce ain ies
Since he signal and no maliza ion decay channels ha e simila kinema ics and opologies,
mos sys ema ic unce ain ies cancel in he a io Rπ/K, e.g. hose ela ed o muon iden i-
ica ion. The emaining con ibu ions o he sys ema ic unce ain y a e lis ed in able 1
and discussed below.
To es ima e he sys ema ic unce ain y ela ed o he i model, pseudoexpe imen s
a e sampled om he baseline i models wi h all pa ame e s ixed om hose ob ained
om he i s o he da a. Fo each pseudoexpe imen i s a e pe o med wi h a numbe
o al e na i e models o he signal and backg ound componen s and he a io Rπ/Kis
compu ed. A gene alized S uden ’s -dis ibu ion [57] and an Apollonios unc ion [58]
a e used as al e na i e models o he signal componen , while polynomial unc ions o
he second and he hi d o de wi h a ious cons ain s o mono onici y and con exi y
a e used as al e na i e backg ounds. The maximum ela i e bias ound o Rπ/Kis 0.7%,
which is assigned as a ela i e sys ema ic unce ain y.
The unce ain y ela ed o he impe ec knowledge o he Λ0
bdecay model used
o he simula ion o he Λ0
b→ψ(2S)pK−decays is es ima ed by a ying he co ec ion
ac o s ob ained om kinema ic dis ibu ions obse ed in da a. Changing hese co ec-
ion ac o s wi hin hei s a is ical unce ain ies causes a negligible a ia ion o he e i-
ciency εΛ0
b
→ψ(2S)pK−. Fo he Λ0
b→ψ(2S)pπ−signal decays he obse ed wo-body mass
dis ibu ions a e in ag eemen wi h he phase-space model used in he simula ion. The co -
esponding unce ain y due o he unknown decay kinema ics o he Λ0
b→ψ(2S)pπ−signal
decays is small and he e o e neglec ed.
An addi ional unce ain y a ises om he di e ences be ween da a and simula ion, in
pa icula hose a ec ing he e iciency o he econs uc ion o cha ged-pa icle acks.
The small di e ence in he ack- inding e iciency be ween da a and simula ion is co ec ed
using a da a-d i en echnique [55]. The unce ain ies in hese co ec ion ac o s oge he
wi h he unce ain ies in he had on-iden i ica ion e iciencies, ela ed o he ini e size o
he calib a ion samples [53,54], a e p opaga ed o he a io o o al e iciencies by means
o pseudoexpe imen s. This esul s in a sys ema ic unce ain y o 0.2% associa ed wi h
he ack econs uc ion and had on iden i ica ion.
The sys ema ic unce ain y on he e iciency o he igge has been p e iously s udied
using high-yield B+→J/ψK+and B+→ψ(2S)K+decays by compa ing a ios o igge
e iciencies in da a and simula ion [59]. Based on hese compa isons a ela i e unce ain y
o 1.1% is assigned.
Ano he sou ce o unce ain y is he po en ial disag eemen be ween da a and simula-
ion in he es ima ion o e iciencies, due o e ec s no conside ed abo e. This is s udied
using a high-yield low-backg ound sample o Λ0
b→J/ψpK−decays, by a ying he selec ion
c i e ia in anges ha lead o as much as ±20% di e ences in he measu ed signal yields.
The esul ing a ia ions in he e iciency-co ec ed yields do no exceed 1% o all inspec ed
selec ion c i e ia. The alue o 1% is aken as a co esponding sys ema ic unce ain y.
Finally, he 0.5% ela i e unce ain y in he a io o e iciencies om eq. (4.2) is assigned
as a sys ema ic unce ain y due o he ini e size o he simula ed samples.
– 6 –
JHEP08(2018)131
Sou ce Unce ain y [%]
Fi model 0.7
T ack econs uc ion and had on iden i ica ion 0.2
T igge 1.1
Selec ion c i e ia 1.0
Size o he simula ion samples 0.5
To al 1.7
Table 1. Rela i e sys ema ic unce ain ies o he a io o b anching ac ions. The o al unce -
ain y is he quad a ic sum o he indi idual con ibu ions.
6 Resul s and summa y
The Cabibbo-supp essed decay Λ0
b→ψ(2S)pπ−is obse ed using a da a sample collec ed
by he LHCb expe imen in p o on-p o on collisions co esponding o 1.0, 2.0 and 1.9 b−1
o in eg a ed luminosi y a cen e-o -mass ene gies o 7, 8 and 13 TeV, espec i ely. The ob-
se ed yield o Λ0
b→ψ(2S)pπ−decays is 121 ±13. Using he Λ0
b→ψ(2S)pK−decay as
a no maliza ion channel, he a io o he b anching ac ions is measu ed o be
Rπ/K=BΛ0
b→ψ(2S)pπ−
BΛ0
b→ψ(2S)pK−= (11.4±1.3±0.2)% ,
whe e he i s unce ain y is s a is ical and he second is sys ema ic. Neglec ing he eso-
nance s uc u es in he Λ0
b→ψ(2S)pπ−and Λ0
b→ψ(2S)pK−decays, he calcula ed alue
o he a io Rπ/Kis
R h
π/K≈Φ3Λ0
b→ψ(2S)pπ−
Φ3Λ0
b→ψ(2S)pK−× an2θC≃11% ,
whe e Φ3deno es he ull h ee-body phase-space and θCis he Cabibbo angle [60].
The measu ed alue is in a good ag eemen wi h his es ima e.
The b anching ac ion BΛ0
b→ψ(2S)pπ−is calcula ed using he alue o
BΛ0
b→ψ(2S)pK−=6.29 ±0.23 ±0.14+1.14
−0.90×10−5[16] as
BΛ0
b→ψ(2S)pπ−=7.17 ±0.82 ±0.33+1.30
−1.03×10−6,
whe e he i s unce ain y is s a is ical, he second sys ema ic (including he s a is ical and
sys ema ic unce ain ies om BΛ0
b→ψ(2S)pK−) and he hi d a ises om he unce -
ain ies in he b anching ac ions o he Λ0
b→J/ψpK−,ψ(2S) →J/ψπ+π−,ψ(2S) →e+e−
and J/ψ→e+e−decays [48].
The ψ(2S)p and ψ(2S)π−mass spec a a e in es iga ed and no e idence o con ibu-
ions om exo ic s a es is ound. Wi h a la ge da a sample a de ailed ampli ude analysis
o his decay could be pe o med, making i possible o sea ch o small con ibu ions om
exo ic s a es.
– 7 –
JHEP08(2018)131
Acknowledgmen s
We exp ess ou g a i ude o ou colleagues in he CERN accele a o depa men s o he
excellen pe o mance o he LHC. We hank he echnical and adminis a i e s a a he
LHCb ins i u es. We acknowledge suppo om CERN and om he na ional agencies:
CAPES, CNPq, FAPERJ and FINEP (B azil); MOST and NSFC (China); CNRS/IN2P3
(F ance); BMBF, DFG and MPG (Ge many); INFN (I aly); NWO (Ne he lands); MNiSW
and NCN (Poland); MEN/IFA (Romania); MinES and FASO (Russia); MinECo (Spain);
SNSF and SER (Swi ze land); NASU (Uk aine); STFC (Uni ed Kingdom); NSF (U.S.A.).
We acknowledge he compu ing esou ces ha a e p o ided by CERN, IN2P3 (F ance),
KIT and DESY (Ge many), INFN (I aly), SURF (Ne he lands), PIC (Spain), G idPP
(Uni ed Kingdom), RRCKI and Yandex LLC (Russia), CSCS (Swi ze land), IFIN-HH
(Romania), CBPF (B azil), PL-GRID (Poland) and OSC (U.S.A.). We a e indeb ed o
he communi ies behind he mul iple open-sou ce so wa e packages on which we depend.
Indi idual g oups o membe s ha e ecei ed suppo om A H Founda ion (Ge many),
EPLANET, Ma ie Sk lodowska-Cu ie Ac ions and ERC (Eu opean Union), ANR, Labex
P2IO and OCEVU, and R´egion Au e gne-Rhˆone-Alpes (F ance), Key Resea ch P og am o
F on ie Sciences o CAS, CAS PIFI, and he Thousand Talen s P og am (China), RFBR,
RSF and Yandex LLC (Russia), GVA, Xun aGal and GENCAT (Spain), He chel Smi h
Fund, he Royal Socie y, he English-Speaking Union and he Le e hulme T us (Uni ed
Kingdom).
Open Access. This a icle is dis ibu ed unde he e ms o he C ea i e Commons
A ibu ion License (CC-BY 4.0), which pe mi s any use, dis ibu ion and ep oduc ion in
any medium, p o ided he o iginal au ho (s) and sou ce a e c edi ed.
Re e ences
[1] LHCb collabo a ion, Measu emen o σ(pp →bbX) a √s= 7 TeV in he o wa d egion,
Phys. Le . B 694 (2010) 209 [a Xi :1009.2731] [INSPIRE].
[2] LHCb collabo a ion, Measu emen o J/ψp oduc ion in pp collisions a √s= 7 TeV ,Eu .
Phys. J. C 71 (2011) 1645 [a Xi :1103.0423] [INSPIRE].
[3] LHCb collabo a ion, P oduc ion o J/ψand Υmesons in pp collisions a √s= 8 TeV ,
JHEP 06 (2013) 064 [a Xi :1304.6977] [INSPIRE].
[4] LHCb collabo a ion, Measu emen o o wa d J/ψp oduc ion c oss-sec ions in pp collisions
a √s= 13 TeV ,JHEP 10 (2015) 172 [E a um ibid. 05 (2017) 063] [a Xi :1509.00771]
[INSPIRE].
[5] LHCb collabo a ion, Measu emen o he b-qua k p oduc ion c oss-sec ion in
7and 13 TeV pp collisions,Phys. Re . Le . 118 (2017) 052002 [E a um ibid. 119 (2017)
169901] [a Xi :1612.05140] [INSPIRE].
[6] LHCb collabo a ion, Measu emen s o he b anching ac ions o B(s) →D(s)πππ and
Λ0
b→Λ+
cπππ,Phys. Re . D 84 (2011) 092001 [E a um ibid. D 85 (2012) 039904]
[a Xi :1109.6831] [INSPIRE].
– 8 –
JHEP08(2018)131
6Aix Ma seille Uni , CNRS/IN2P3, CPPM, Ma seille, F ance
7LAL, Uni . Pa is-Sud, CNRS/IN2P3, Uni e si ´e Pa is-Saclay, O say, F ance
8LPNHE, So bonne Uni e si ´e, Pa is Dide o So bonne Pa is Ci ´e, CNRS/IN2P3, Pa is, F ance
9I. Physikalisches Ins i u , RWTH Aachen Uni e si y, Aachen, Ge many
10 Fakul ¨a Physik, Technische Uni e si ¨a Do mund, Do mund, Ge many
11 Max-Planck-Ins i u ¨u Ke nphysik (MPIK), Heidelbe g, Ge many
12 Physikalisches Ins i u , Rup ech -Ka ls-Uni e si ¨a Heidelbe g, Heidelbe g, Ge many
13 School o Physics, Uni e si y College Dublin, Dublin, I eland
14 INFN Sezione di Ba i, Ba i, I aly
15 INFN Sezione di Bologna, Bologna, I aly
16 INFN Sezione di Fe a a, Fe a a, I aly
17 INFN Sezione di Fi enze, Fi enze, I aly
18 INFN Labo a o i Nazionali di F asca i, F asca i, I aly
19 INFN Sezione di Geno a, Geno a, I aly
20 INFN Sezione di Milano-Bicocca, Milano, I aly
21 INFN Sezione di Milano, Milano, I aly
22 INFN Sezione di Caglia i, Monse a o, I aly
23 INFN Sezione di Pado a, Pado a, I aly
24 INFN Sezione di Pisa, Pisa, I aly
25 INFN Sezione di Roma To Ve ga a, Roma, I aly
26 INFN Sezione di Roma La Sapienza, Roma, I aly
27 Nikhe Na ional Ins i u e o Suba omic Physics, Ams e dam, Ne he lands
28 Nikhe Na ional Ins i u e o Suba omic Physics and VU Uni e si y Ams e dam, Ams e dam,
Ne he lands
29 Hen yk Niewodniczanski Ins i u e o Nuclea Physics Polish Academy o Sciences, K ak´ow, Poland
30 AGH - Uni e si y o Science and Technology, Facul y o Physics and Applied Compu e Science,
K ak´ow, Poland
31 Na ional Cen e o Nuclea Resea ch (NCBJ), Wa saw, Poland
32 Ho ia Hulubei Na ional Ins i u e o Physics and Nuclea Enginee ing, Bucha es -Magu ele,
Romania
33 Pe e sbu g Nuclea Physics Ins i u e (PNPI), Ga china, Russia
34 Ins i u e o Theo e ical and Expe imen al Physics (ITEP), Moscow, Russia
35 Ins i u e o Nuclea Physics, Moscow S a e Uni e si y (SINP MSU), Moscow, Russia
36 Ins i u e o Nuclea Resea ch o he Russian Academy o Sciences (INR RAS), Moscow, Russia
37 Yandex School o Da a Analysis, Moscow, Russia
38 Budke Ins i u e o Nuclea Physics (SB RAS), No osibi sk, Russia
39 Ins i u e o High Ene gy Physics (IHEP), P o ino, Russia
40 ICCUB, Uni e si a de Ba celona, Ba celona, Spain
41 Ins i u o Galego de F´ısica de Al as Ene x´ıas (IGFAE), Uni e sidade de San iago de Compos ela,
San iago de Compos ela, Spain
42 Eu opean O ganiza ion o Nuclea Resea ch (CERN), Gene a, Swi ze land
43 Ins i u e o Physics, Ecole Poly echnique F´ed´e ale de Lausanne (EPFL), Lausanne, Swi ze land
44 Physik-Ins i u , Uni e si ¨a Z¨u ich, Z¨u ich, Swi ze land
45 NSC Kha ki Ins i u e o Physics and Technology (NSC KIPT), Kha ki , Uk aine
46 Ins i u e o Nuclea Resea ch o he Na ional Academy o Sciences (KINR), Kyi , Uk aine
47 Uni e si y o Bi mingham, Bi mingham, Uni ed Kingdom
48 H.H. Wills Physics Labo a o y, Uni e si y o B is ol, B is ol, Uni ed Kingdom
49 Ca endish Labo a o y, Uni e si y o Camb idge, Camb idge, Uni ed Kingdom
50 Depa men o Physics, Uni e si y o Wa wick, Co en y, Uni ed Kingdom
51 STFC Ru he o d Apple on Labo a o y, Didco , Uni ed Kingdom
52 School o Physics and As onomy, Uni e si y o Edinbu gh, Edinbu gh, Uni ed Kingdom
53 School o Physics and As onomy, Uni e si y o Glasgow, Glasgow, Uni ed Kingdom
– 15 –

JHEP08(2018)131
54 Oli e Lodge Labo a o y, Uni e si y o Li e pool, Li e pool, Uni ed Kingdom
55 Impe ial College London, London, Uni ed Kingdom
56 School o Physics and As onomy, Uni e si y o Manches e , Manches e , Uni ed Kingdom
57 Depa men o Physics, Uni e si y o Ox o d, Ox o d, Uni ed Kingdom
58 Massachuse s Ins i u e o Technology, Camb idge, MA, Uni ed S a es
59 Uni e si y o Cincinna i, Cincinna i, OH, Uni ed S a es
60 Uni e si y o Ma yland, College Pa k, MD, Uni ed S a es
61 Sy acuse Uni e si y, Sy acuse, NY, Uni ed S a es
62 Pon i ´ıcia Uni e sidade Ca ´olica do Rio de Janei o (PUC-Rio), Rio de Janei o, B azil,
associa ed o 2
63 Uni e si y o Chinese Academy o Sciences, Beijing, China, associa ed o 3
64 School o Physics and Technology, Wuhan Uni e si y, Wuhan, China, associa ed o 3
65 Ins i u e o Pa icle Physics, Cen al China No mal Uni e si y, Wuhan, Hubei, China,
associa ed o 3
66 Depa amen o de Fisica, Uni e sidad Nacional de Colombia, Bogo a, Colombia, associa ed o 8
67 Ins i u ¨u Physik, Uni e si ¨a Ros ock, Ros ock, Ge many, associa ed o 12
68 Van Swinde en Ins i u e, Uni e si y o G oningen, G oningen, Ne he lands, associa ed o 27
69 Na ional Resea ch Cen e Ku cha o Ins i u e, Moscow, Russia, associa ed o 34
70 Na ional Uni e si y o Science and Technology “MISIS”, Moscow, Russia, associa ed o 34
71 Na ional Resea ch Tomsk Poly echnic Uni e si y, Tomsk, Russia, associa ed o 34
72 Ins i u o de Fisica Co puscula , Cen o Mix o Uni e sidad de Valencia - CSIC, Valencia, Spain,
associa ed o 40
73 Uni e si y o Michigan, Ann A bo , Uni ed S a es, associa ed o 61
74 Los Alamos Na ional Labo a o y (LANL), Los Alamos, Uni ed S a es, associa ed o 61
aUni e sidade Fede al do T iˆangulo Minei o (UFTM), Ube aba-MG, B azil
bLabo a oi e Lep ince-Ringue , Palaiseau, F ance
cP.N. Lebede Physical Ins i u e, Russian Academy o Science (LPI RAS), Moscow, Russia
dUni e si `a di Ba i, Ba i, I aly
eUni e si `a di Bologna, Bologna, I aly
Uni e si `a di Caglia i, Caglia i, I aly
gUni e si `a di Fe a a, Fe a a, I aly
hUni e si `a di Geno a, Geno a, I aly
iUni e si `a di Milano Bicocca, Milano, I aly
jUni e si `a di Roma To Ve ga a, Roma, I aly
kUni e si `a di Roma La Sapienza, Roma, I aly
lAGH - Uni e si y o Science and Technology, Facul y o Compu e Science, Elec onics and
Telecommunica ions, K ak´ow, Poland
mLIFAELS, La Salle, Uni e si a Ramon Llull, Ba celona, Spain
nHanoi Uni e si y o Science, Hanoi, Vie nam
oUni e si `a di Pado a, Pado a, I aly
pUni e si `a di Pisa, Pisa, I aly
qUni e si `a degli S udi di Milano, Milano, I aly
Uni e si `a di U bino, U bino, I aly
sUni e si `a della Basilica a, Po enza, I aly
Scuola No male Supe io e, Pisa, I aly
uUni e si `a di Modena e Reggio Emilia, Modena, I aly
MSU - Iligan Ins i u e o Technology (MSU-IIT), Iligan, Philippines
wNo osibi sk S a e Uni e si y, No osibi sk, Russia
xNa ional Resea ch Uni e si y Highe School o Economics, Moscow, Russia
ySezione INFN di T ies e, T ies e, I aly
zEscuela Ag ´ıcola Paname icana, San An onio de O ien e, Hondu as
– 16 –
JHEP08(2018)131
aa School o Physics and In o ma ion Technology, Shaanxi No mal Uni e si y (SNNU), Xi’an, China
ab Physics and Mic o Elec onic College, Hunan Uni e si y, Changsha Ci y, China
†Deceased
– 17 –