Observation of B0s →K*∓ K∓ and evidence for B0s →K* −π+ decays

PAPER • OPEN ACCESS
Obse a ion o and e idence o
decays
To ci e his a icle: The LHCb Collabo a ion1 e al 2014 New J. Phys. 16 123001
View he a icle online o upda es and enhancemen s.
Rela ed con en
CP iola ion in he B sys em
T Ge shon and V V Gligo o
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Recen cha m physics esul s om BABAR
Ryan M Whi e
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CP iola ion, UK Phenomenology
Wo kshop 2000
Tobias Hu h, Choong Sun Kim, Clai e
Shephe d-Themis ocleous e al.
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Recen ci a ions
A e ages o b-had on, c-had on, and
$$ au $$ -lep on p ope ies as o summe
2016
Y. Amhis e al
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Op ical diagnos ics o eac i e species in
a mosphe ic-p essu e non he mal plasma
Ryo Ono
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A mosphe ic p essu e plasma je s: an
o e iew o de ices and new di ec ions
J Win e e al
-
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Obse a ion o B0
s→K7K∓and e idence o
B0
s→K−
π+decays
The LHCb Collabo a ion
1
Recei ed 31 July 2014, e ised 24 Sep embe 2014
Accep ed o publica ion 10 Oc obe 2014
Published 2 Decembe 2014
New Jou nal o Physics 16 (2014) 123001
doi:10.1088/1367-2630/16/12/123001
Abs ac
Measu emen s o he b anching ac ions o →±∓
BKK
*
s
0and π→±
∓
BK
*
s
0
decays a e pe o med using a da a sample co esponding o −
1.0 b
1
o p o on-
p o on collision da a collec ed wi h he LHCb de ec o a a cen e-o -mass
ene gy o
7
Te
V
, whe e he
±
K
*
mesons a e econs uc ed in he
π
±
K
S
0final
s a e. The fi s obse a ion o he →±∓
BKK
*
s
0decay and he fi s e idence o
he π→−
+
BK
*
s
0decay a e epo ed wi h b anching ac ions

π
→=±±×
→=±±×
±∓ −
−+−
()
()
BKK
BK
*(12.7 1.9 1.9) 10 ,
*(3.3 1.1 0.5) 10 ,
s
s
06
06
whe e he fi s unce ain ies a e s a is ical and he second a e sys ema ic. In
addi ion, an uppe limi o

→<×
±∓ −
()
BKK
*0.4 (0.5) 10
06
is se a
9
0% (95%) confidence le el.
Keywo ds: fla ou physics, B physics, b anching ac ion
1. In oduc ion
The S anda d Model (SM) o pa icle physics p edic s ha all mani es a ions o CP iola ion,
i.e. iola ion o symme y unde he combined cha ge conjuga ion and pa i y ope a ion, a ise
due o he single complex phase ha appea s in he Cabibbo–Kobayashi–Maskawa (CKM)
qua k mixing ma ix [1,2]. Since his sou ce is no su ficien o accoun o he le el o he
1
Au ho s a e lis ed a he end o he pape .
Con en om his wo k may be used unde he e ms o he C ea i e Commons A ibu ion 3.0 licence.
Any u he dis ibu ion o his wo k mus main ain a ibu ion o he au ho (s) and he i le o he wo k, jou nal
ci a ion and DOI. A icle unded by SCOAP
3
.
New Jou nal o Physics 16 (2014) 123001
1367-2630/14/123001+18$33.00 © 2014 CERN
ba yon asymme y o he Uni e se [3], one o he key goals o con empo a y pa icle physics is
o sea ch o signa u es o CP iola ion ha a e no consis en wi h he CKM pa adigm.
Among he mos impo an a eas being explo ed in qua k fla ou physics is he s udy o B
meson decays o had onic final s a es ha do no con ain cha m qua ks o an iqua ks (he ea e
e e ed o as ‘cha mless’). As shown in figu e 1, such decays ha e, in gene al, ampli udes ha
con ain con ibu ions om bo h ‘ ee’and ‘loop’diag ams (see, e.g., [4]). The phase di e ences
be ween he wo ampli udes can lead o CP iola ion and, since pa icles hypo hesized in
ex ensions o he SM may a ec he loop diag ams, de ia ions om he SM p edic ions may
occu . La ge CP iola ion e ec s, i.e. asymme ies o

(10%) o mo e be ween he a es o B
¯
and Bmeson decays o CP conjuga e final s a es, ha e been seen in π→+−
BK
0[5–8],
π→−
+
BK
s
0[7,8], and ππ→
++−+
BK
,
+−+
K
KK
,πππ
+−+
and
π
+−
+
K
K
decays [9–11].
Howe e , i is ha d o be ce ain whe he hese measu emen s a e consis en wi h he SM
p edic ions due o he p esence o pa ame e s desc ibing he had onic in e ac ions ha a e
di ficul o de e mine ei he heo e ically o om da a.
An in e es ing app oach o con ol he had onic unce ain ies is o exploi ampli ude
analysis echniques. Fo example, by s udying he dis ibu ion o kinema ic configu a ions o
ππ→+−
BK
S
00decays ac oss he Dali z plo [12], he ela i e phase be ween he
π
+−
K
*
and
ρ
K
S
00ampli udes can be de e mined. This in o ma ion is no accessible in s udies ei he o wo-
body decays, o o he inclusi e p ope ies o h ee-body decays. Consequen ly, i may be
possible o make mo e sensi i e es s o he SM by s udying decays o final s a es ha ing
con ibu ions om in e media e s a es wi h one ec o and one pseudoscala meson (VP), a he
han in hose wi h wo pseudoscala s.
Se e al me hods o es he SM wi h Bmesondecays ocha mlessVP(
π
K
*
and ρ
K
) s a es
ha e been p oposed [13–18]. The expe imen al inpu s needed o hese me hods a e he
magni udes and ela i e phases o he decay ampli udes. Al hough he phases can only be ob ained
om Dali z plo analyses o Bmeson decays o final s a es con aining one kaon and wo pions, he
magni udes can be ob ained om simplified app oaches. Dali z plo analyses ha e been pe o med
o he decays ππ→
+++−
BK [19,20], ππ→+−
BK
S
00[21,22]and ππ→+−
BK
00
[23]. Decays
o Bmesons o
K
K
*
final s a es can in p inciple be s udied wi h simila me hods, bu he exis ing
expe imen al esul s a e less p ecise [24–29]. No p e ious measu emen s o
B
s
0
meson decays o
cha mless VP final s a es exis . Fi s esul s om he LHCb collabo a ion on inclusi e h ee-body
cha mless
B
s
0
decays ha e ecen ly become a ailable [30], bu no a emp has p e iously been
made o sepa a e he di e en esonan and non esonan con ibu ions o hei Dali z plo s.
In his pape , he fi s measu emen s o
B
s
0
meson decays o
π
−
+
K
*
and
±∓
K
K
*
final s a es
and o he
→
±
∓
BKK
*
0
a e a e epo ed. Th oughou he emainde o he pape he symbol
K
*is used o deno e he
K
*(892
)
esonance. Unique cha ge assignmen s o he final s a e
Figu e 1. (a) T ee and (b) loop diag ams o he decay →+−
B
KK
*
s
0.
2
New J. Phys. 16 (2014) 123001 R Aaij e al
pa icles a e specified in he exp ession π→−
+
BK
*
s
0because he ampli ude o π→+−
BK
*
s
0
is expec ed o be negligibly small; howe e , he inclusion o cha ge-conjuga e p ocesses is
implied h oughou he pape . The b anching ac ions a e measu ed ela i e o ha o he
π→+−
BK
*
0decay, which is known om p e ious measu emen s,
π→ =±×
+− −
()
BK
*(8.5 0.7) 10
06
[31]. Each o he ela i e b anching ac ions o
→±∓
BKh
*
s
0, whe e h e e s ei he o a pion o kaon, a e de e mined as

π
ϵπ
ϵπ
→
→
=
→
→
→
→
±∓
+−
+−
±∓
±∓
+−
()
()
()
()
()
()
BKh
BK
BK
BKh
NB K h
NB K
,(1)
*
*
*
*
*
*
sd
ss
s
0
0
0
0
0
0
while ha o
→
±
∓
BKK
*
0
is de e mined as

π
ϵπ
ϵπ
→
→
=
→
→
→
→
±∓
+−
+−
±∓
±∓
+−
()
()
()
()
()
()
BKK
BK
BK
BKK
NB K K
NB K
,(2)
*
*
*
*
*
*
0
0
0
0
0
0
whe e Na e signal yields ob ained om da a, ϵa e e ficiencies ob ained om simula ion and
co ec ed o known disc epancies be ween da a and simula ion, and he a io o agmen a ion
ac ions
=± 0.259 0.01
5
sd
[32–34]. Wi h his app oach, se e al po en ially la ge
sys ema ic unce ain ies cancel in he a ios. The
±
K
*
mesons a e econs uc ed in hei decays
o
π
±
K
S
0wi h ππ→+
−
K
S
0and he e o e he final s a es
π
±∓
K
h
S
0
, as well as he da a sample, a e
iden ical o hose s udied in [30].
Al hough he analysis sha es se e al common ea u es o ha o he p e ious publica ion
[30], he selec ion is op imized independen ly based on he expec ed le el o backg ound wi hin
he allowed
π
±
K
S
0mass window. The da a sample used is oo small o a de ailed Dali z plo
analysis, and he e o e only b anching ac ions a e measu ed. The fi used o dis inguish signal
om backg ound is an unbinned maximum likelihood fi in he wo dimensions o Bcandida e and
K
*
candida e in a ian masses. This app oach allows he esonan →±
∓
BKh
*decay obe
sepa a ed om o he Bmeson decays o he
π
±∓
K
h
S
0
final s a e. I does no , howe e , accoun o
in e e ence e ec s be ween he ±∓
K
h
*
componen and o he ampli udes con ibu ing o he Dali z
plo ; possible biases due o in e e ence a e conside ed as a sou ce o sys ema ic unce ain y.
2. The LHCb de ec o
The analysis is based on a da a sample co esponding o an in eg a ed luminosi y o −
1.0 b
1
o
pp collisions a a cen e-o -mass ene gy o
7
Te
V
eco ded wi h he LHCb de ec o a CERN.
The LHCb de ec o [35] is a single-a m o wa d spec ome e co e ing he pseudo apidi y ange
η<<
2
5
, designed o he s udy o pa icles con aining bo cqua 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 (VELO) [36]
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 [37] placed downs eam. The acking sys em p o ides a momen um
measu emen wi h ela i e unce ain y ha a ies om 0.4% a low momen um o 0.6% a
100 GeV/c. The minimum dis ance o a ack o a p ima y e ex, he impac pa ame e , is
measu ed wi h esolu ion o μ
2
0m
o acks wi h la ge momen um ans e se o he beamline
(
p
T
). 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 [38]. Pho on, elec on and had on candida es a e iden ified by a
3
New J. Phys. 16 (2014) 123001 R Aaij e al
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 ified by a sys em composed o
al e na ing laye s o i on and mul iwi e p opo ional chambe s [39].
The igge [40] consis s o ha dwa e and so wa e s ages. The had on igge a he
ha dwa e s age equi es ha he e is a leas one pa icle wi h ans e se ene gy
>
E
3.5Ge
V
T.
E en s con aining candida e signal decays a e equi ed o ha e been igge ed a he ha dwa e
le el in one o wo ways. E en s in he fi s ca ego y a e igge ed by pa icles om candida e
signal decays ha ha e an associa ed calo ime e ene gy deposi abo e he h eshold, while
hose in he second ca ego y a e igge ed independen ly o he pa icles associa ed wi h he
signal decay. E en s ha do no all in o ei he o hese ca ego ies a e no used in he subsequen
analysis. The so wa e igge equi es a wo-, h ee- o ou - ack seconda y e ex wi h a la ge
sum o he
p
T
o he acks and a significan displacemen om he p ima y pp in e ac ion
e ices (PVs). A mul i a ia e algo i hm [41] is used o he iden ifica ion o seconda y e ices
consis en wi h he decay o a bhad on.
Simula ed e en s a e used o s udy he de ec o esponse o signal decays and o in es iga e
po en ial sou ces o backg ound. In he simula ion, pp collisions a e gene a ed using PYTHIA
[42] wi h a specific LHCb configu a ion [43]. Decays o had onic pa icles a e desc ibed by
EVTGEN [44], in which final s a e adia ion is gene a ed using PHOTOS [45]. 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 GEANT4
oolki [46] as desc ibed in [47].
3. Selec ion equi emen s
The igge and p eselec ion equi emen s a e iden ical o hose in [30]. As in ha analysis, and
hose o o he final s a es con aining
K
S
0
mesons [48–52], candida e signal decays, i.e.
combina ions o acks ha a e consis en wi h he signal hypo hesis, a e sepa a ed in o wo
ca ego ies: ‘long’, whe e bo h acks om he ππ→+
−
K
S
0decay con ain hi s in he VELO, and
‘downs eam’, whe e nei he does. Bo h ca ego ies ha e associa ed hi s in he acking de ec o s
downs eam o he magne . Since long candida es ha e be e mass, momen um and e ex
esolu ion, di e en selec ion equi emen s a e imposed o he wo ca ego ies.
The wo acks o igina ing om he Bdecay e ex, e e ed o he ea e as ‘bachelo ’
acks, a e equi ed no o ha e associa ed hi s in he muon sys em. Backg ounds om decays
wi h cha m o cha monia in he in e media e s a e a e e oed by emo ing candida es wi h wo-
body in a ian mass unde he app op ia e final s a e hypo hesis wi hin
3
0MeV/c
o he known
masses [53]. Ve oes a e applied o
ψππ→+−
J
o
+−
K
K
,χππ→+−
c0o
+−
K
K
,π→−+
DK
0,
ππ
+−
o
+−
K
K
,
π→
+
+
DK
S
0
o +
K
K
S
0,
π→
+
+
DK
sS
0
o +
K
K
S
0and
Λ→
+
Kp
cS
0
decays.
The la ges sou ce o po en ial backg ound is om andom combina ions o final s a e
pa icles, he ea e e e ed o as combina o ial backg ound. Signal candida es a e sepa a ed om
his sou ce o backg ound wi h he ou pu o a neu al ne wo k [54] ha is ained and op imized
sepa a ely o long and downs eam candida es. In he aining, simula ed →±∓
BKK
*
s
0decays
a e used o ep esen signal, and da a om he high mass sideband o ππ
+
−
K
S
0candida es a e
used as a backg ound sample ( he sideband is ππ<−<
+−
mK m
4
0 ( ) 150 MeV/c
SB
00,whe e
m
B
0is he known alue o he B
0
mass [53]). The a iables used a e: he alues o he impac
pa ame e χ
2
,defined as he di e ence in χ
2
o he associa ed PV wi h and wi hou he
conside ed pa icle, o he bachelo acks and he
K
S
0
and Bcandida es; he e ex fi χ
2
o he
4
New J. Phys. 16 (2014) 123001 R Aaij e al

K
S
0
and Bcandida es; he angle be ween he Bcandida e fligh di ec ion and he line be ween he
associa ed PV and he decay e ex; he sepa a ion be ween he PV and he decay e ex di ided
by i s unce ain y; and he Bcandida e
p
T
. Some o hese a iables a e ans o med in o hei
loga i hms o o he o ms ha a e mo e app op ia e o nume ical handling. The consis ency o
he dis ibu ions o hese a iables be ween da a and simula ion is confi med o ππ→+−
BK
S
00
decays using he sPlo echnique [55]wi h heBcandida e mass as disc imina ing a iable.
The c i e ia on he ou pu s o he neu al ne wo k a e chosen o op imize he p obabili y o
obse e he →±∓
BKK
*
s
0decay wi h significance exceeding fi e s anda d de ia ions (σ)[56].
Fo he op imiza ion, an addi ional equi emen on he
π
±
K
S
0in a ian mass,
π−<
±±
mK m( ) 100 MeV/c
SK
0*wi h
±
mK* he known
±
K
*
mass, calcula ed wi h he Band
K
S
0
candida es cons ained o hei known masses, is imposed o selec he
±
K
*
domina ed
egion o he phase space. The equi emen s on he neu al ne wo k ou pu gi e signal
e ficiencies exceeding 90% o candida es con aining long
K
S
0
candida es and exceeding 80%
o candida es con aining downs eam
K
S
0
candida es, while app oxima ely 95% and 92% o he
backg ound is emo ed om he wo ca ego ies, espec i ely.
Requi emen s a e imposed on pa icle iden ifica ion in o ma ion, p ima ily om he ing-
imaging Che enko de ec o s [38], o sepa a e
±∓
K
K
*
and
π
±
∓
K
*
decays. The c i e ia a e
chosen based on op imiza ion o a simila figu e o me i o ha used o ob ain he equi emen
on he neu al ne wo k ou pu , and e ain abou 70% o
±∓
K
K
*
and abou 75% o
π
±
∓
K
*
decays.
Candida es wi h acks ha a e likely o be p o ons a e ejec ed. A e all selec ion equi emen s
a e applied, below
1%
o e en s con aining one candida e also con ain a second candida e; all
such candida es a e e ained.
4. De e mina ion o signal yields
Candida es wi h masses inside he fi windows o
π<<
±∓
mK h
5
000 ( ) 5500 MeV/c
S
0and
π<<
±
mK650 ( ) 1200 MeV/c
S
0a e used o pe o m ex ended unbinned maximum likelihood
fi s o de e mine he signal yields. In hese fi s, signal decays a e sepa a ed om se e al
ca ego ies o backg ound by exploi ing hei dis ibu ions in bo h
π
±∓
mK h()
S
0
and π±
mK(
)
S
0.
The mass o he
π
±∓
K
h
S
0
combina ion is calcula ed assigning ei he he kaon o pion mass o
∓
h
acco ding o he ou come o he pa icle iden ifica ion equi emen . A single simul aneous fi o
bo h long and downs eam candida es is pe o med. Sepa a e fi s a e pe o med o
±∓
K
K
*
and
π
±
∓
K
*
candida es.
In addi ion o he signal componen s and combina o ial backg ound, candida es can
o igina e om se e al o he bhad on decays. Po en ial sou ces include: decays o B0and
B
s
0
mesons o
π
±∓
K
h
S
0
final s a es wi hou an in e media e
K
*s a e ( e e ed o as ‘non esonan ’);
misiden ified
→
±∓
BKh
*
s()
0( e e ed o as ‘c oss- eed’)andΛ→−
Kp
*
b
0decays; decays o B
mesons o cha mless final s a es wi h an addi ional un econs uc ed pion; and
→
+
+
BDh
¯
0,
ππ→+−
DK
¯S
00decays whe e he addi ional pion is no econs uc ed. Whe e b anching ac ion
measu emen s exis [31,50,53], he yields o he backg ound sou ces, excep ha o
non esonan ππ→+−
BK
S
00decays, a e expec ed o be less han 10% o hose o →±∓
BKK
*.
s
0
The b anching ac ions o he o he non esonan decays ha e no been p e iously de e mined.
The fi includes componen s o bo h B0and
B
s
0
signal and non esonan componen s, and
he sou ces o backg ound lis ed abo e. The signal componen s a e pa ame ized by a C ys al
5
New J. Phys. 16 (2014) 123001 R Aaij e al
Ball (CB) unc ion [57]inBcandida e mass and a ela i is ic B ei –Wigne (RBW) unc ion in
K
*candida e mass. The peak posi ions and wid hs o he unc ions o he dominan con ibu ion
(
B
s
0
o
±∓
K
K
*
,B0 o
π
±
∓
K
*
) a e allowed o a y eely in he fi . The ela i e posi ions o he
B0and
B
s
0
peaks in he Bcandida e mass dis ibu ion a e fixed acco ding o he known B0–
B
s
0
mass di e ence [53]. The ail pa ame e s o he CB unc ion a e fixed o he alues oundinfi s o
simula ed signal e en s, as a e he ela i e wid hs o he B0and
B
s
0
shapes. C oss- eed
con ibu ions a e also desc ibed by he p oduc o CB and RBW unc ions wi h pa ame e s
de e mined om simula ion. The misiden ifica ion causes a shi and a smea ing o he B
candida e mass dis ibu ion and only small changes o he shape in he
K
*candida e mass.
The Bcandida e mass dis ibu ions o he non esonan componen s a e also pa ame ized
by a CB unc ion, wi h peak posi ions and wid hs iden ical o hose o he signal componen s,
bu wi h di e en ail pa ame e s ha a e fixed o alues ob ained om simula ion. Wi hin he
K
*mass window conside ed in he fi , he non esonan shape can be app oxima ed wi h a linea
unc ion. All linea unc ions used in he fi a e pa ame ized by hei yield and he abscissa
alue a which hey c oss ze o, and a e se o ze o beyond his h eshold, m
0
. The ela i e yields
o non esonan and signal componen s a e cons ained o ha e he same alue in he samples
wi h long and downs eam candida es, bu his a io is allowed o be di e en o B0and
B
s
0
decays.
Backg ounds om o he bhad on decays a e desc ibed nonpa ame ically by ke nel
unc ions [58] in he Bcandida e mass and ei he RBW o linea unc ions in he
K
*candida e
mass, depending on whe he o no he decay in ol es a
K
* esonance. All hese backg ound
shapes a e de e mined om simula ion. To educe he numbe o ee pa ame e s in he fi o he
±∓
K
K
*
sample, he yields o he backg ounds om cha mless had onic Bmeson decays wi h
missing pa icles a e fixed ela i e o he yield o he π→+−
BK
*
0c oss- eed componen
acco ding o expec a ion. The yield o he
→
+
+
BDh
¯
0,ππ→+−
DK
¯S
00componen is
de e mined om he fi o da a. The yield o he Λ→−
Kp
*
b
0con ibu ion is also a ee
pa ame e in he fi o
±∓
K
K
*
candida es, bu is fixed o ze o in he fi o
π
±
∓
K
*
candida es.
The combina o ial backg ound is modelled wi h linea unc ions in bo h Band
K
*
candida e mass dis ibu ions, wi h pa ame e s eely a ied in he fi o da a excep o he m
0
h eshold in Bcandida e mass, which is fixed om fi s o sideband da a. Fo all componen s, he
ac o iza ion o he wo-dimensional p obabili y densi y unc ions in o he p oduc o one-
dimensional unc ions is e ified o be a good app oxima ion using simula ion and sideband
da a. In o al he e a e 20 ee pa ame e s in he fi o he
±∓
K
K
*
sample: yields o B0and
B
s
0
signals, c oss- eed, Λ,
b
0
→BDh
and combina o ial backg ounds (all o bo h long and
downs eam ca ego ies); a ios o yields o he B0and
B
s
0
non esonan componen s; peak
posi ion and wid h pa ame e s o he signal in bo h Bcandida e and
K
*candida e mass
dis ibu ions; and pa ame e s o he linea unc ions desc ibing he combina o ial backg ound in
K
*candida e mass o bo h long and downs eam ca ego ies. The fi o he
π
±
∓
K
*
sample has
he same numbe o ee pa ame e s, wi h he
Λ
b
0
backg ound yields eplaced by cha mless
backg ound yields. The s abili y o bo h fi s is confi med using simula ed pseudoexpe imen s.
The esul s o he fi s a e shown in figu es 2and 3 o he
±∓
K
K
*
and
π
±
∓
K
*
final s a es,
espec i ely, and he signal yields a e gi en in able 1. All o he fi esul s a e consis en wi h
expec a ions.
6
New J. Phys. 16 (2014) 123001 R Aaij e al
5. Sys ema ic unce ain ies
Sys ema ic unce ain ies occu due o possible impe ec ions in he fi model used o de e mine
he signal yields, and due o impe ec knowledge o he e ficiencies used o con e he yields
o b anching ac ion esul s. A summa y o he sys ema ic unce ain ies is gi en in able 2.
The fixed pa ame e s in he unc ions desc ibing he signal and backg ound componen s
a e a ied wi hin hei unce ain ies, and he changes in he fi ed yields a e assigned as
sys ema ic unce ain ies. S udies wi h simula ed pseudoexpe imen s canno exclude biases on
Figu e 2. Resul s o he fi o ±∓
KK
*candida es p ojec ed on o (a), (b) Bcandida e
and (c), (d)
K*
candida e mass dis ibu ions, o (a), (c) long and (b), (d) downs eam
candida es. The o al fi esul (solid black line) is shown oge he wi h he da a
poin s. Componen s o he
B
0(pink dash double-do ed line) and
B
s
0
( ed dash do ed
line) signals a e shown oge he wi h he
B
s
0
non esonan componen (da k ed
alling-ha ched a ea), cha mless pa ially econs uc ed and c oss- eed backg ound
(blue long-dashed line), and combina o ial backg ound (g een long-dash do ed line)
componen s. The
→
++
B
Dh
¯
0
backg ound componen has a nega i e yield
(consis en wi h ze o) and so is no di ec ly isible bu causes he o al PDF o go
below he le el o he combina o ial backg ound on he le o he Bcandida e mass
spec um.
7
New J. Phys. 16 (2014) 123001 R Aaij e al
Figu e 3. Resul s o he fi o
π
±∓
K*
candida es p ojec ed on o (a), (b) Bcandida e and
(c), (d)
K*
candida e mass dis ibu ions, o (a), (c) long and (b), (d) downs eam
candida es. The o al fi esul (black solid line) is shown oge he wi h he da a poin s.
Componen s o he
B
0( ed dash do ed line) and
B
s
0
(pink dash double-do ed line)
signals a e shown oge he wi h
B
0(da k ed alling-ha ched a ea) and
B
s
0
(pu ple
ising-ha ched a ea) non esonan componen s, pa ially econs uc ed and c oss- eed
backg ound (blue long-dashed line), and combina o ial backg ound (g een long-dash-
do ed line) componen s.
Table 1. Yields and ela i e yields ob ained om he fi s o ±∓
KK
*and
π
±∓
K*
can-
dida es. The ela i e yields o non esonan (NR)
B
s()
0
decays a e cons ained o be
iden ical in long and downs eam ca ego ies. Only s a is ical unce ain ies a e gi en.
Yield
B
0
B
s
0
Long Downs eam Long Downs eam
±∓
N
KK(*
)
0±4 4±3 40±8 62±10
π
±∓
N
K(*
)
80±10 165±16 5±4 23±8
π±∓ ±∓
N
KK NKK(NR)(
*
)
S
00.0 ± 1.0 0.41 ± 0.16
ππ π
±∓ ±∓
N
KNK(NR)(
*
)
S
00.79 ± 0.14 0.6 ± 0.4
8
New J. Phys. 16 (2014) 123001 R Aaij e al
13
School o Physics, Uni e si y College Dublin, Dublin, I eland
14
Sezione INFN di Ba i, Ba i, I aly
15
Sezione INFN di Bologna, Bologna, I aly
16
Sezione INFN di Caglia i, Caglia i, I aly
17
Sezione INFN di Fe a a, Fe a a, I aly
18
Sezione INFN di Fi enze, Fi enze, I aly
19
Labo a o i Nazionali dell’INFN di F asca i, F asca i, I aly
20
Sezione INFN di Geno a, Geno a, I aly
21
Sezione INFN di Milano Bicocca, Milano, I aly
22
Sezione INFN di Milano, Milano, I aly
23
Sezione INFN di Pado a, Pado a, I aly
24
Sezione INFN di Pisa, Pisa, I aly
25
Sezione INFN di Roma To Ve ga a, Roma, I aly
26
Sezione INFN di Roma La Sapienza, Roma, I aly
27
Hen yk Niewodniczanski Ins i u e o Nuclea Physics Polish Academy o Sciences, K aków, Poland
28
AGH-Uni e si y o Science and Technology, Facul y o Physics and Applied Compu e Science, K aków,
Poland
29
Na ional Cen e o Nuclea Resea ch (NCBJ), Wa saw, Poland
30
Ho ia Hulubei Na ional Ins i u e o Physics and Nuclea Enginee ing, Bucha es -Magu ele, Romania
31
Pe e sbu g Nuclea Physics Ins i u e (PNPI), Ga china, Russia
32
Ins i u e o Theo e ical and Expe imen al Physics (ITEP), Moscow, Russia
33
Ins i u e o Nuclea Physics, Moscow S a e Uni e si y (SINP MSU), Moscow, Russia
34
Ins i u e o Nuclea Resea ch o he Russian Academy o Sciences (INR RAN), Moscow, Russia
35
Budke Ins i u e o Nuclea Physics (SB RAS) and No osibi sk S a e Uni e si y, No osibi sk, Russia
36
Ins i u e o High Ene gy Physics (IHEP), P o ino, Russia
37
Uni e si a de Ba celona, Ba celona, Spain
38
Uni e sidad de San iago de Compos ela, San iago de Compos ela, Spain
39
Eu opean O ganiza ion o Nuclea Resea ch (CERN), Gene a, Swi ze land
40
Ecole Poly echnique Fédé ale de Lausanne (EPFL), Lausanne, Swi ze land
41
Physik-Ins i u , Uni e si ä Zü ich, Zü ich, Swi ze land
42
Nikhe Na ional Ins i u e o Suba omic Physics, Ams e dam, The Ne he lands
43
Nikhe Na ional Ins i u e o Suba omic Physics and VU Uni e si y Ams e dam, Ams e dam, The Ne he lands
44
NSC Kha ki Ins i u e o Physics and Technology (NSC KIPT), Kha ki , Uk aine
45
Ins i u e o Nuclea Resea ch o he Na ional Academy o Sciences (KINR), Kyi , Uk aine
46
Uni e si y o Bi mingham, Bi mingham, UK
47
H. H. Wills Physics Labo a o y, Uni e si y o B is ol, B is ol, UK
48
Ca endish Labo a o y, Uni e si y o Camb idge, Camb idge, UK
49
Depa men o Physics, Uni e si y o Wa wick, Co en y, UK
50
STFC Ru he o d Apple on Labo a o y, Didco , UK
51
School o Physics and As onomy, Uni e si y o Edinbu gh, Edinbu gh, UK
52
School o Physics and As onomy, Uni e si y o Glasgow, Glasgow, UK
53
Oli e Lodge Labo a o y, Uni e si y o Li e pool, Li e pool, UK
54
Impe ial College London, London, UK
55
School o Physics and As onomy, Uni e si y o Manches e , Manches e , UK
56
Depa men o Physics, Uni e si y o Ox o d, Ox o d, UK
57
Massachuse s Ins i u e o Technology, Camb idge, MA, USA
58
Uni e si y o Cincinna i, Cincinna i, OH, USA
59
Uni e si y o Ma yland, College Pa k, MD, USA
60
Sy acuse Uni e si y, Sy acuse, NY, USA
61
Pon i ícia Uni e sidade Ca ólica do Rio de Janei o (PUC-Rio), Rio de Janei o, B azil, associa ed o
3
62
Ins i u e o Pa icle Physics, Cen al China No mal Uni e si y, Wuhan, Hubei, China, associa ed o
4
63
Ins i u ü Physik, Uni e si ä Ros ock, Ros ock, Ge many, associa ed o
12
64
Na ional Resea ch Cen e Ku cha o Ins i u e, Moscow, Russia, associa ed o
32
65
Ins i u o de Fisica Co puscula (IFIC), Uni e si a de Valencia-CSIC, Valencia, Spain, associa ed o
37
66
KVI-Uni e si y o G oningen, G oningen, The Ne he lands, associa ed o
42
67
Celal Baya Uni e si y, Manisa, Tu key, associa ed o
39
68
Uni e sidade Fede al do T iângulo Minei o (UFTM), Ube aba-MG, B azil
69
P N Lebede Physical Ins i u e, Russian Academy o Science (LPI RAS), Moscow, Russia
15
New J. Phys. 16 (2014) 123001 R Aaij e al

70
Uni e si à di Ba i, Ba i, I aly
71
Uni e si à di Bologna, Bologna, I aly
72
Uni e si à di Caglia i, Caglia i, I aly
73
Uni e si à di Fe a a, Fe a a, I aly
74
Uni e si à di Fi enze, Fi enze, I aly
75
Uni e si à di U bino, U bino, I aly
76
Uni e si à di Modena e Reggio Emilia, Modena, I aly
77
Uni e si à di Geno a, Geno a, I aly
78
Uni e si à di Milano Bicocca, Milano, I aly
79
Uni e si à di Roma To Ve ga a, Roma, I aly
80
Uni e si à di Roma La Sapienza, Roma, I aly
81
Uni e si à della Basilica a, Po enza, I aly
82
AGH-Uni e si y o Science and Technology, Facul y o Compu e Science, Elec onics and
Telecommunica ions, K aków, Poland
83
LIFAELS, La Salle, Uni e si a Ramon Llull, Ba celona, Spain
84
Hanoi Uni e si y o Science, Hanoi, Vie Nam
85
Uni e si à di Pado a, Pado a, I aly
86
Uni e si à di Pisa, Pisa, I aly
87
Scuola No male Supe io e, Pisa, I aly
88
Uni e si à degli S udi di Milano, Milano, I aly
89
Poli ecnico di Milano, Milano, I aly
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