Measurement of B_s^0 meson production in pp and PbPb collisions at sqrt(s_NN)=5.02 TeV

Contents lists available atScienceDirect

Physics

Letters

B

www.elsevier.com/locate/physletb

Measurement

of

B

meson

production

in

pp

and

PbPb

collisions

at

√

s

=

5

.

02 TeV

Receivedinrevisedform27June2019 Accepted4July2019

Availableonline9July2019 Editor:M.Doser

Keywords:

Physics

Quarkgluonplasma Bmeson

Openheavy-flavor

Theproductioncrosssections ofB0s mesonsandchargeconjugatesaremeasuredinproton-proton(pp) and PbPb collisions via the exclusive decay channel B0s→J/ψφ→μ+μ−K+K− at a center-of-mass energyof5.02 TeVpernucleonpairandwithintherapidityrange_|y_| <2.4 usingtheCMSdetectorat theLHC.Theppmeasurementisperformedasafunctionoftransversemomentum(pT)oftheB0smesons intherangeof7to50 GeV/c andiscomparedtothepredictionsofperturbativeQCDcalculations.The B0

s productionyield inPbPbcollisions is measuredintwo pT intervals, 7to 15 and 15 to50 GeV/c, andcomparedtotheyieldinppcollisionsinthesamekinematicregion.Thenuclearmodificationfactor (RAA)is foundtobe1.5±0.6(stat) ±0.5(syst) for7–15 GeV/c, and 0.87±0.30(stat) ±0.17(syst) for 15–50 GeV/c, respectively. Withincurrent uncertainties,the B0

s results are consistent withmodels of strangenessenhancement,andsuppressionbypartonenergyloss,asobservedfortheB+mesons.

PublishedbyElsevierB.V.ThisisanopenaccessarticleundertheCCBYlicense (http://creativecommons.org/licenses/by/4.0/).FundedbySCOAP3_.

1. Introduction

Relativistic heavy ion collisions allow the study of quantum chromodynamics (QCD) at high energy densityand temperature. Under such extreme conditions, a state consisting of deconfined quarks and gluons, the quark-gluon plasma (QGP) [1,2], is pre-dicted by lattice QCD calculations [3]. The study of the phe-nomenoninwhichtheoutgoingpartonsinteractstronglywiththe QGPandloseenergyby means ofelasticcollisions and medium-inducedgluonradiation [4–8] canprovideinsightsintotheenergy densityanddiffusionpropertiesoftheQGP. Heavyquarks are ef-fective probes to study these properties of the medium. Charm andbeautyquarksthatareprimarilyproducedinhardscatterings atthe early stages ofthe collision are expectedto carry the full evolutionhistory oftheQGP formation [8].On theother handit isexpected [9] that,via theprocess gg→ss,an enhancement of strangenessinathermallyandchemicallyequilibratedQGPshould occurifitstemperatureisabovethestrangequarkmass. Measure-ments attheBNLRHIC oftheproduction ofstrange baryonsand mesons,usingdifferentcollisionsystemsandbeamenergies, pro-vide systematicsupport forthis expectation [10–14]. Because of theinterplaybetweenthepredictedenhancementofstrangequark production and the quenching mechanismof beauty quarks, the measurement of strange beauty particles is important for study-ing the mechanisms of beauty hadronization in heavy ion

colli- _{E-mailaddress:cms-publication-committee-chair@cern.ch.}

sions. In the presence of a medium with increased strangeness content [15,16], the relative yield of B0

s mesons withrespect to

nonstrange beauty mesons at transverse momentum (pT) below

∼15 GeV/c [8,17] canbe enhanced in nucleus-nucleus collisions compared to proton-proton (pp) interactions. This can happen if recombination is a significant factor of beauty hadronization in the QGP [18–20]. The recombination processes, which are con-sidered markers forthe presence of a deconfined medium, were mostrecently testedinthe open charmsector by theALICE Col-laboration [21].Apossiblehintforanenhancementintherelative yield of D+_s mesons withrespect tononstrange charmedmesons for pT<8 GeV/c incentralPbPbcollisionsatacenter-of-mass

en-ergyof√sNN=5.02 TeVpernucleonpairwasobserved.

The productionof B0_s mesons was previously measured atthe CERNLHCbytheCMSCollaborationinppcollisionsata center-of-massenergyof√s=7 TeV [22] andinproton-lead(pPb)collisions at√sNN=5.02 TeV [23].Inthisletter,wereportthefirst

measure-ment of exclusive B0_s meson decays ever performed in nucleus-nucleus collisions and inpp collisions at 5.02 TeV.The pp mea-surement isperformed asa function of pT andcompared to the

predictions of fixed-order plus next-to-leading order logarithmic (FONLL)perturbativeQCDcalculations [24–26].Thenuclear modi-ficationfactor(RAA)ofBs0 mesons,whichisdefinedastheratioof

the yield in PbPb collisions with respect to that in pp collisions scaled by the corresponding number of binary nucleon-nucleon (NN) collisions,isshown. Thecomparisonbetweenthe RAA ofB0s

mesonsandthatofB+mesonsmeasuredbyCMSatthesame en-ergy [27] isalsopresented.

https://doi.org/10.1016/j.physletb.2019.07.014

The B0_s meson and its charge conjugate are measured in the rapidityrange|y|<2.4 viathe reconstructionofthedecay chan-nelB0s→J/ψφ→μ+μ−K+K−,which hasthe branchingfraction

B = (3.12±0.24)×10−5 _{[28].Theppmeasurementisperformed}

as a function of the B0_s pT in three intervals, 7–15, 15–20, and

20–50 GeV/c.ThePbPbproductionyieldandthe RAAmeasurement

areperformedintwo pT intervals, 7–15and15–50 GeV/c,

inclu-sivelyforallevents(i.e.,0–100%centrality,thedegreeofoverlapof thetwo collidingnuclei).Throughout theletter, unlessotherwise specified,the y and pTvariablesgivenarethoseoftheB0s mesons.

Thisanalysisdoesnotdistinguishbetweenthechargeconjugates.

2. Experimentalapparatusanddatasample

The central feature of the CMS detector is a superconduct-ing solenoid, which provides a magnetic field of 3.8 T. Within the solenoidvolume are a silicon tracker that measures charged particles in the pseudorapidity range |η|<2.5, a lead tungstate crystal electromagnetic calorimeter, and a brass and scintillator hadroncalorimeter.Forchargedparticlesof1<pT<10 GeV/c and

|η|<1.4,thetrackresolutions aretypically1.5%in pT and25–90

(45–150) μm in the transverse (longitudinal) impact parameter [29]. Muonsare measured in the range|η|<2.4, withdetection planes made using three technologies: drift tubes, cathode strip chambers,andresistive-plate chambers. Themuon reconstruction algorithmstartsbyfindingtracksinthemuondetectors,whichare thenfittedtogetherwithtracksreconstructedinthesilicontracker to form “global muons”.Matching muons to tracks measured in the silicon tracker results in a relative pT resolution for muons

with20<pT<100 GeV/c of1.3–2.0%inthebarrel(|η|<1.2)and

better than6% inthe endcaps (1.6<|η|<2.4). Formuons with higher pT up to1 TeV/c,the pT resolutioninthe barrelisbetter

than10% [30].The hadronforward(HF)calorimeteruses steelas an absorber and quartz fibers as the sensitive material. The two halves of the HF are located 11.2 m away from the interaction point,one oneach end, providingtogether coverage intherange 3.0<|η|<5.2.Inthisanalysis,theHFinformationisusedfor per-forming an offline event selection. A detailed description of the CMSexperimentandcoordinatesystemcanbefoundinRef. [31].

Several Monte Carlo (MC) simulated event samples are used to evaluate background components, signal efficiencies, and de-tector acceptance corrections. The simulations include samples containing only the B0_s meson decay channels being measured, andsampleswithinclusive(promptandnonprompt) J/ψmesons. Proton-protoncollisionsaregeneratedwith pythia8v212 [32] tune CUETP8M1 [33] and propagated through the CMS detectorusing the Geant4 package [34]. The decay of the B0_s mesons is mod-eled with evtgen 1.3.0 [35], and final-state photon radiation in the B0

s decays is simulated with photos 2.0 [36]. For the PbPb

MCsamples,each pythia8eventisembeddedintoaPbPbcollision eventgeneratedwith hydjet 1.8 [37],whichistunedtoreproduce globaleventproperties,suchasthe charged-hadron pT spectrum

and particle multiplicity. For both samples, the signal pT shape

is reweighted to match the one from FONLL. For both p p and PbPb dataandMC samples,the dimuonand ditrack mass distri-butions/resolutionsareconsistent.

Eventswerecollectedwiththesametriggerduringtheppand PbPbdataacquisition,requiringthepresenceoftwomuon candi-dates(withnoexplicitmomentumthreshold)incoincidencewith a bunch crossing. Forthe offline analysis, events have to pass a setofselectioncriteriadesignedtorejecteventsfrombackground processes(beam-gas collisions and beamscraping events) as de-scribed inRef. [38]. Events are requiredto have atleast one re-constructed primary interaction vertex, formed by two or more tracks,withadistancefromthecenterofthenominalinteraction

region of less than 15 cm along the beam axis. In PbPb colli-sions, the shapes of the clusters in the pixel detector have to be compatiblewiththose expected fromparticles producedby a PbPbcollision [39].Inordertoselecthadroniccollisions,thePbPb events arealso requiredto have atleastthree towers in each of the HF detectors with energy deposits of more than 3 GeV per tower. The combinedefficiencyforthiseventselection, including the remaining non-hadronic contamination, is (99±2)%. Values higherthan100%are possible,reflectingthepotentialpresenceof ultra-peripheral(i.e.,non-hadronic)collisionsintheselectedevent sample. The PbPb sample corresponds to an integrated luminos-ityofapproximately351 μb−1_{.Thisvalueisindicativeonly,asthe}

PbPb yield is normalized by the total number of minimum bias eventssampled, NMB[38].Theppdatasetcorrespondstoan

inte-gratedluminosityof28.0 pb−1_{,whichisknowntoanaccuracyof}

±2.3%fromtheuncertaintyinthecalibrationbasedona vander Meer scan [40]. The average number of additional collisions per bunchcrossing isapproximately0.9forpp andlessthan0.01 for PbPb data.The presenceofmultiple collisions isfound tohavea negligibleeffectonthemeasurement.

3. Signalextraction

TheanalysisprocedureiscommonforppandPbPbdata. Kine-matic limits are imposed on the single muons so that their re-construction efficiency stays above 10%. These limits are pμ_T > 3.5 GeV/c for|ημ|<1.2, pμ_T >1.8 GeV/c for2.1≤ |ημ|<2.4,and linearlyinterpolatedinthe1.2<|ημ_{|<2.1 region.Themuonsare}

alsorequiredtomatchthemuonsthattriggeredtheeventonline, andtopass selectioncriteriaoptimized forlow pT (the so-called

soft selection [30]).Twomuonsofopposite sign(OS), withan in-variantmasswithin±150 MeV/c2_{oftheworld-averageJ/ψmeson}

mass [28] areselectedtoreconstructaJ/ψ candidate,withamass resolution of typically 18–55 MeV/c2, depending on the dimuon rapidityandpT.TheOSmuonpairsarefittedwithacommon

ver-tex constraintandare kept if thep-value ofthe χ2 _{ofthe fit is}

greater than 1%, thus lowering the background from charm and beautyhadronsemileptonicdecays.Similarly, theφmeson candi-dates are formed withacommon vertexconstraintbetweentwo OS charged-particle tracks with pT>300(150) MeV/c for PbPb

(p p) sample, both requiredto pass standard selections [38]. The invariant mass,with a resolution of ∼3.9(3.4) MeV/c2 _forPbPb

(p p)data,isrequiredtobewithin15 MeV/c2 oftheworld-average φ mesonmass [28]. TheB0

s mesoncandidatesare constructedby

combiningtheJ/ψandφcandidatesandrequiringthatthey orig-inatefromacommonvertex.Withoutusingparticleidentification, assumptions need to be made about the masses of the charged particles. Thedifference betweenthe naturalwidth(according to PDG [41])andthemeasuredwidth(reflectingdetectorresolution) ofthepeaksismuchbiggerfortheJ/ψ mesonthanfortheφ me-son. Therefore, in calculating the mass ofthe B0_s candidates, the two charged particles are always assumed to have the mass of charged kaons, andthe muon pair is assumedto have the mass ofaJ/ψmeson.

The B0_s candidates are selected according to their daughter chargedparticletrackkinematics,the χ2_{probabilityoftheirdecay}

vertex(the probability forthe muon tracks fromthe J/ψ meson decay and the other charged particle tracks to originate from a commonvertex),thedistancebetweentheprimaryanddecay ver-tices (normalized byits uncertainty), andthepointingangle(the anglebetweenthelinesegmentconnectingtheprimaryanddecay vertices andthe momentumvector ofthe B0

s meson). The

selec-tion is optimized separately for pp and PbPb results as well as each individual pT bin, using a multivariate technique that

Fig. 1. InvariantmassdistributionsofB0s candidatesinpp(left)andPbPb(right)collisionsmeasuredintherange|y|<2.4 andinthe pT rangeof7–15 GeV/c.The χ2

dividedbythenumberofdegreesoffreedom(nDOF)isalsogiven.

Fig. 2. InvariantmassdistributionsofB0

s candidatesinpp(left)andPbPb(right)collisionsmeasuredintherange|y|<2.4 andinthepTrangeof15–50 GeV/c.The χ2

dividedbythenumberofdegreesoffreedom(nDOF)isalsogiven.

maximizethe statisticalsignificanceofthe B0

s mesonsignals. The

B0_s signal samples are takenfrom simulation.The signal samples are scaled to the number of B0s candidates predicted by FONLL

calculationscorresponding totheintegratedluminosityofthe an-alyzeddatasample.Thisnormalizationisnotusedwhen perform-ingtheBDTtraining.Thebackgroundsamplesforthemultivariate training are taken from data sidebands of the B0_s meson invari-antmass(0.2<|MμμKK−MB0

s,PDG|<0.3 GeV/c

2_{),whichisabout}

5σ away fromthePDGB0_s massvalue.The optimalselection cri-terion is the working point with the highest signal significance (Ns/√(Ns+Nb), where Ns (Nb) are the expected signal

(back-ground) candidate yields from the simulated signal (data side-bands)withinthemassrange|MμμKK−MB0

s,PDG|<0.08 GeV/c

2_.

TherawyieldsofB0_s mesonsinppandPbPbcollisions are ex-tractedusinganextendedunbinnedmaximumlikelihoodfittothe invariantmassdistributionoftheB0_s candidatesinthemassrange 5–6 GeV/c2_{. The estimation ofthe statisticaluncertainties ofthe}

fittedraw yields isbased on thesecond derivativesof the nega-tivelog-likelihoodfunction.Examplesoffitstotheinvariantmass distributionsinppandPbPbcollisions areshowninFigs.1and2 forthe pT regions 7–15and15–50 GeV/c,respectively.Thesignal

shapeismodeledbytwoGaussianfunctionswithacommonmean

(which isafree parametertogetherwiththeamplitude),and dif-ferentwidthsindividuallydeterminedfromMCsimulationsforthe ppandPbPbresults.TherelativecontributionofthetwoGaussian functionstothesignalyieldisalsofixedatthevaluegivenbythe MCsample.Thebackgroundisdominatedbyrandomcombinations ofpromptandnonpromptJ/ψcandidateswithextraparticlesand it ismodeledby afirst-orderpolynomial,asdeterminedby stud-ies oftheinclusiveJ/ψ MC sample.Peakingstructuresthat could arisefromthebackgroundcontaminationofotherBmesondecays (e.g.,B0→J/ψK∗0)werefoundtobenegligibleasaconsequence ofthetightselectiononthemassoftheφcandidate.

The differential crosssection forB0

s production in|y|<2.4 is

computedineach pTintervalaccordingto

dσB0s dpT    |y|<2.4 =1 2 1 B L 1 pT N(B 0 s+B 0 s) pp (pT) αpp(pT)pp(pT)   _| y|<2.4 , (1)

forppdata,andforPbPbdataaccordingto

1 TAA dNB0s PbPb dpT    |y|<2.4

=1 2 1 BNMBTAA 1 pT × N(B0s+B 0 s) PbPb (pT) αPbPb(pT)PbPb(pT)   _| y|<2.4 . (2) The N(B0s+B 0 s)

pp,PbPb is therawsignalyield extractedineach pT interval

of width pT, (α, )pp,PbPb represents the corresponding

accep-tancetimesefficiency,andBisthebranchingfractionofthedecay chain. For the pp cross section, L represents the integrated lu-minosity, andfor the PbPb cross section, NMB is the number of

minimumbiaseventsand TAA isthenuclearoverlapfunction [43].

The TAA is equal to the number of NN binary collisions divided

by theNN total inelasticcross section, andit can be interpreted astheNN-equivalentintegratedluminosityperheavyioncollision. The TAA valueforinclusivePbPbcollisions at√sNN=5.02 TeVis

(5.6±0.2)mb−1 asestimatedfromanMCGlaubermodel [38,43]. Assumingthat, in thekinematic regionaccessible by the present measurement,theB0

s andB 0

s productioncross sectionsareequal,

thefactor 1/2accountsfor thefact that the yields are measured forparticlesandantiparticlesaddedtogether,butthecrosssection isgivenforonespeciesonly.

4. Systematicuncertainties

Thecrosssectionmeasurementsareaffectedbyseveralsources ofsystematicuncertaintiesarising fromthesignal extraction, cor-rections, B, L, NMB, and TAA determination. Unless mentioned

otherwise,thesameprocedures wereusedtoestimate the uncer-taintiesforthep pandPbPbresults.Theuncertaintyofthesignal modelingisevaluatedbyconsideringfourfitvariations:(i) increas-ing/decreasing thewidthparameters determined fromsimulation by 4% (the maximum relative statistical uncertainty ofthe fitted widthparameteramongall pT bins fromp p andPbPbdata); (ii)

usingasingle Gaussianfunction; (iii)usingasumofthree Gaus-sian functions with a common mean, and, (iv) fixing the mean of the Gaussian function to the value determined from simula-tion. The uncertainty in the modeling of the background shapes isalsoevaluated byvarying theprobability distributionfunctions usedtodescribethebackgroundtoahigher-orderpolynomialand exponential function. The maximum of the signal variations and themaximumof allthe backgroundvariations are propagated as systematicuncertainties.Forthep presults,thesystematic uncer-taintyduetotheselectionoftheB0

s mesoncandidatesisestimated

bycomparingtheBDT-obtainednominalresultwiththeresults us-inga cut-based method(arectangularcut)that uses theGenetic Algorithmtodeterminethebestcutvalueforeachparameter [42]. Thesamesignal andbackgroundshape parametrizationareused, and the same analysis parameters are optimized as in the BDT nominalmethod.The significanceis similarforthe two methods (∼8) forthe p p bins.This provides an estimate of the potential difference betweendifferentselection criteria. The full difference between the two methods is propagated as a systematic uncer-tainty.For the PbPb results,because of the small signal indata, inordertominimizetheimpactofstatisticalfluctuations,a differ-entapproachwastaken. Inthiscase, theB0_s selectionuncertainty wasestimatedusingthe ppdatasample, asthefull differencein theyield betweenthep presultswiththeBDTtrainedonthep p sample(the nominalresult)andtheresultswiththe BDTtrained onthePbPbsample(theselectionusedforthePbPbresults).

Thebin-by-binsystematicuncertaintiesassociatedwiththe ac-ceptance correction are estimated by varying the shape of the generated B0_s meson pT and y spectra. For the purpose of the

systematicstudies only, both data andMC are splitinto four pT

andy bins. Theratiobetweendataandsimulated pT spectra

(in-cludingtheirstatisticaluncertainties)isusedtogenerate pseudo-experiments (‘toys’). Each toy is fit with a polynomial, which is

Table 1

Summaryofsystematicuncertaintiesinpercentage(%)fromeachsourceinppand PbPbanalyses. Collisionsystem pp PbPb pTinterval(GeV/c) [7,15] [15,20] [20,50] [7,15] [15,50] Signalmodeling 2.5 0.7 0.7 4.2 3.5 Backgroundmodeling 3.4 1.6 1.6 8.7 0.68 B0 sselection 15 2.6 2.6 19 8.6 B0 sacceptance 1.7 1.4 1.7 1.7 1.7 B0sefficiency 6.5 0.5 0.9 7.9 3.8 MCsamplesize 0.8 0.8 0.5 4.9 2.1 Muontrigger, reconstruction,and identification 4.4 3.3 3.0 5.1 3.8

Hadrontrackingefficiency 8 8 8 12 12 Total 19 9.4 9.3 26 16 Branchingfractions 7.6

Numberofminimumbias eventsinPbPbdata – 2 TAA – +2.8/−3.4 Integratedluminosityofpp data 2.3 –

then used to reweight the MC B0

s meson pT spectra. A new

ac-ceptance value is calculated for each modified shape, for each kinematicbin.Therootmeansquare (RMS)ofallacceptances de-termined viatoys ispropagated asthe systematicuncertaintyby choosing the maximumRMS value emerging fromthe pT and y

shapevariations.Becauseofthesmallsignalavailable,forthePbPb resultsthep p ratioisusedtogeneratethetoys. Thereisalsoan uncertaintyassignedtoaccountforpotentialbiasintheefficiency calculationsfromtheFONLLsimulationsoftheB0s meson pTshape.

Thisuncertaintyiscalculatedasthedifferencebetweenthe nomi-nalresultsandthoseobtainedbygeneratingthe pythia pT shape.

An additional uncertainty comes from the finite size of the MC samples. This is determined by the statisticaluncertainty of the simulatedsignal,afterapplyingallselectioncriteria.

The uncertainty in the efficiency of the muon trigger, recon-struction, andidentification isevaluated bin-by-bin usingcontrol samples indata [44]. Arelative systematicuncertainty of4% per hadrontrackinppcollisions [29] and6%inPbPbcollisions [38] is alsoconsidered,toaccountfortheuncertaintyinthetrack recon-structionefficiency.Thisuncertaintypropagatesto8%and12%for theB0_s measurementinppandPbPb,respectively. Thesystematic uncertaintyinthecrosssection measurementiscomputedasthe suminquadratureofthedifferentcontributionsmentionedabove. TheuncertaintyintheB0_s mesondecayB is7.6% [28].The uncer-taintyfor NMB accountsfortheinefficiencyoftheeventselection

andthe triggerinselecting hadronicevents [38]. The TAA

uncer-tainty is +2.8%, −3.4% [38]. Inthe calculationsofthe systematic uncertainties oftheB0

s meson RAA andtheRAA ratiobetweenB0s

andB+,correlated uncertaintiesfromthe trackandmuon recon-structionandidentificationarepartiallycanceled.

Thevaluesforeachsystematicuncertaintysourcearelisted in Table1.

5. Results

InFig.3andinthetoppanelofFig.4,the pT-differential

pro-duction crosssectionsinpp andPbPb collisions measuredin the interval |y|<2.4 are presented. The pp results are compared to the predictions of FONLL calculations [26]. The FONLL reference cross section isobtained by multiplying the FONLL totalb quark production [24–26] by the world-average production fraction of B0s of10.3% [28]. The B0s FONLL predictionis consistentwith the

measuredB0

Fig. 3. ThepT-differentialproductioncrosssectionofB0s inppcollisionsat

√

s=

5.02 TeVinthreepTintervalsfrom7to50 GeV/c.Theverticalbars(boxes)

cor-respondtostatistical(systematic)uncertainties.Theglobalsystematicuncertainty, listedinthelegendandnotincludedinthepoint-to-pointuncertainties,comprises theuncertaintiesintheintegratedluminositymeasurementandinthebranching fractionB.TheppcrosssectioniscomparedtoFONLLcalculations [26] represented bythecoloredyellowboxeswiththeheightsindicatingthetheoreticaluncertainty.

spectrumhasasmalleruncertaintythanthatoftheFONLL calcu-lation.

The nuclear modificationfactor RAA,shown inFig. 4,is

com-putedas: RAA(pT)= 1 TAA dNB0s PbPb dpT  dσB0s pp dpT . (3) The B0

s meson RAA is 1.5±0.6(stat)±0.5(syst) for 7–15 GeV/c,

and0.87±0.30(stat)±0.17(syst)for15–50 GeV/c,respectively.In the bottompanel of Fig. 4, the RAA of B+ mesons froma

previ-ousmeasurement [27] isalsoshown.ComparedtotheB+mesons, there is an indication of an enhancement for B0_s mesons, which wouldbe the expectationinthe presenceof acontribution from beautyrecombinationwithstrangequarksinheavyioncollisions. However, the B0_s RAA values arecompatible withunity andtheir

largeuncertaintiesdonotexcludeasignificantsuppression.The pT

dependenceof RAAiscomparedtotheB0s predictionofa

perturba-tiveQCD basedmodelthat includesbothcollisionalandradiative energyloss,(CUJET3.0) [45–47],andatransportmodelbasedona Langevinequation that includescollisionalenergyloss andheavy quark diffusion in the medium, (TAMU) [17,48]. The difference betweenthe two models below pT∼15 GeV reflects the

contri-bution from recombination processes, which are included in the TAMU but not in the CUJET3.0 model.The results measured for

pT>7 GeV/c havethe powerto disentanglethetwo models,

al-beit afteran increase inprecision,which canbe achievedwitha biggerdatasample.

Tofurtherquantifythesignificanceofapossibleenhancement ofthe B0_s/B+ ratioin PbPb withrespect to pp collisions, the ra-tio betweenthe B0

s and the B+ RAA is also calculated,canceling

thesystematicuncertaintysourcesthatarecommontoboth mea-surements(acceptance,trackingefficiency,andmuon-related).The B+ RAAwithawider pTbinning(15–50 GeV/c)isobtainedbyaB+

yield weighted averageof theresults fromthree pT bins (15–20,

20–30and30–50 GeV/c)presentedinpreviouswork [27].The re-sultisshowninFig.5.The ratiois 4.0±1.8(stat)±1.3(syst) for 7–15 GeV/c, and 1.8±0.7(stat)±0.3(syst) for 15–50 GeV/c, re-spectively.AssumingaGaussiandistributionwithmeanandwidth equaltothatofthe RAAratioanditsuncertainty(including

statis-ticalandsystematiccomponentsaddedinquadrature),the

hypoth-Fig. 4. (top)ThepT-differentialproductioncrosssectionofB0s mesonsinpp

colli-sionsandthe pT-differentialcorrectedyieldofB0s mesonsscaledbyTAAinPbPb

collisionsat√sNN=5.02 TeVintwopTintervalsfrom7to50 GeV/c.Thevertical

bars(boxes)correspondtostatistical(systematic)uncertainties.Theglobal system-aticuncertaintycomprisestheuncertaintiesinTAA,NMB,andB.(bottom)The

nu-clearmodificationfactorRAAofB0smeasuredinPbPbcollisionsat√sNN=5.02 TeV

from 7to50 GeV/c.Theverticalbars(boxes) correspondto statistical (system-atic)uncertainties.TheB+ RAAmeasurement [27] isalsoshownforcomparison.

Theglobalsystematicuncertainty,representedbythegreyboxat RAA=1,

com-prisestheuncertaintiesintheintegratedluminositymeasurementand TAAvalue.

TwoB0s theoreticalcalculationsarealsoshownforcomparison:TAMU [17,48] and

CUJET3.0 [45–47].ThelinewidthofthetheoreticalcalculationfromRefs. [17,48] representsthesizeofitsstatisticaluncertainty.

esisof theratio valuesbeingconsistent withunity (no enhance-ment)istestedwitha χ2 _{test.Theresultingp-valuesare18%and}

28%for7–15and15–50 GeV/c,respectively.Thisshowsthat,with a p-value cutoffof5%,thescenarioofnoenhancementcannotbe rejected. This analysisdemonstrates the capability ofperforming a fullyreconstructedB0_s measurementinPbPbcollisions withthe CMSdetector.

6. Summary

Thefirstmeasurementofthedifferentialproductioncross sec-tion of B0_s mesons(including both charge conjugates) in bothpp andPbPbcollisionsatacenter-of-massenergyof5.02 TeVper nu-cleon pair ispresented. The B0

s and B 0

s mesons are studied with

the CMS detector at the LHC in the rapidity range |y|<2.4 via the reconstructionof oneoftheir exclusive hadronicdecay chan-nels, B0s→J/ψφ→μ+μ−K+K−. The nuclear modification factor

Fig. 5. ThenuclearmodificationfactorRAAratiobetweenB0s andB+ measuredin

PbPbcollisionsat√sNN=5.02 TeVfrom7to50 GeV/c.TwoB0s theoretical

calcula-tionsarealsoshownforcomparison:TAMU [17,48],andCUJET3.0 [45–47].

7 to 50 GeV/c,inclusively for0–100% event centrality. A hintof an enhancement of the B0

s/B+ ratio in PbPb with respect to pp

collisions is seen. More precise measurements of the B0_s andB± mesons RAA with the upcoming high-luminosity LHC heavy ion

runscould providefurtherconstraintsontherelevance of recom-bination,a markerof deconfined matter, forbeauty hadron pro-duction,and unambiguous informationabout themechanisms of beautyhadronizationinheavyioncollisions.

Acknowledgements

WecongratulateourcolleaguesintheCERNaccelerator depart-ments for the excellent performance of the LHC and thank the technicalandadministrativestaffs atCERN andatother CMS in-stitutes for their contributions to the success of the CMS effort. Inaddition,wegratefullyacknowledgethecomputingcentersand personneloftheWorldwideLHCComputingGridfordeliveringso effectivelythecomputinginfrastructure essential toour analyses. Finally, we acknowledge the enduring support for the construc-tionandoperationofthe LHCandtheCMSdetectorprovided by thefollowingfundingagencies: BMBWFandFWF(Austria);FNRS andFWO (Belgium); CNPq, CAPES, FAPERJ,FAPERGS, andFAPESP (Brazil); MES (Bulgaria); CERN; CAS, MOST, and NSFC (China); COLCIENCIAS (Colombia); MSES and CSF (Croatia); RPF (Cyprus); SENESCYT(Ecuador);MoER,ERCIUT,andERDF(Estonia);Academy ofFinland,MEC,andHIP(Finland);CEAandCNRS/IN2P3(France); BMBF, DFG, and HGF (Germany); GSRT (Greece); NKFIA (Hun-gary);DAEandDST (India);IPM(Iran);SFI(Ireland);INFN (Italy); MSIPandNRF(Republic ofKorea);MES (Latvia);LAS (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, andUASLP-FAI(Mexico);MOS(Montenegro);MBIE(NewZealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna);MON,ROSATOM,RAS,RFBR,andNRCKI(Russia);MESTD (Serbia);SEIDI,CPAN,PCTI,andFEDER(Spain);MoSTR (SriLanka); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter, IPST, STAR, and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASUand SFFR(Ukraine); STFC (United Kingdom);DOE andNSF (USA).

Individuals have received support from the Marie-Curie pro-gramme and the European Research Council and Horizon 2020 Grant, contract No. 675440 (European Union); the A.G. Leventis Foundation;theA. P. SloanFoundation;the Alexandervon Hum-boldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation à la Recherche dansl’Industrie et dans

l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the F.R.S.-FNRS and FWO (Belgium) under the “Excellence of Science - EOS” - be.h projectn.30820817; theMinistryofEducation,Youth andSports (MEYS) of the Czech Republic; the Lendület (“Momentum”) Pro-gramme and the János Bolyai Research Scholarship of the Hun-garianAcademyofSciences,theNewNationalExcellenceProgram ÚNKP,theNKFIAresearchgrants123842,123959,124845,124850 and125105 (Hungary); the Council ofScience andIndustrial Re-search, India; the HOMING PLUS programme of the Foundation forPolishScience,cofinancedfromEuropeanUnion,European Re-gional Development Fund, the Mobility Plus programme of the Ministry of Science and Higher Education, the National Science Center (Poland), contracts Harmonia 2014/14/M/ST2/00428, Opus 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, and 2015/19/B/ST2/ 02861,Sonata-bis2012/07/E/ST2/01406;theNationalPriorities Re-search Program by Qatar National Research Fund; the Programa EstataldeFomento delaInvestigación CientíficayTécnica de Ex-celencia María de Maeztu, grant MDM-2015-0509 and the Pro-grama Severo Ochoa del Principado de Asturias; the Thalis and Aristeia programmes cofinanced by EU-ESF andthe Greek NSRF; theRachadapisekSompotFundforPostdoctoralFellowship, Chula-longkornUniversityandtheChulalongkornAcademic intoIts2nd CenturyProjectAdvancement Project(Thailand);theWelch Foun-dation,contractC-1845;andtheWestonHavensFoundation(USA).

References

[1] É.V.Shuryak,Theoryofhadronicplasma,Sov.Phys.JETP47(1978)212,http:// www.jetp.ac.ru/cgi-bin/e/index/e/47/2/p212?a=list.

[2] J.C. Collins, M.J. Perry, Superdense matter: neutrons or asymptotically free quarks?Phys. Rev.Lett.34(1975) 1353,https://doi.org/10.1103/PhysRevLett. 34.1353.

[3]F.Karsch, E.Laermann,Thermodynamics and in-mediumhadronproperties fromlatticeQCD,in:R.Hwa(Ed.),Quark-GluonPlasmaIII,2003,arXiv:hep -lat/0305025.

[4] J.D. Bjorken,Energy lossofenergetic partons inquark-gluon plasma: pos-sible extinction of high pT jets in hadron-hadroncollisions, Fermilab PUB

82-059-THY,http://lss.fnal.gov/archive/1982/pub/Pub-82-059-T.pdf,1982. [5] R. Baier, D. Schiff, B.G. Zakharov, Energy loss in perturbative QCD, Annu.

Rev.Nucl.Part.Sci.50(2000)37,https://doi.org/10.1146/annurev.nucl.50.1.37, arXiv:hep-ph/0002198.

[6] CMSCollaboration,ObservationandstudiesofjetquenchinginPbPbcollisions at √sNN=2.76 TeV,Phys.Rev.C84(2011)024906,https://doi.org/10.1103/ PhysRevC.84.024906,arXiv:1102.1957.

[7] ATLASCollaboration, Observationofacentrality-dependentdijetasymmetry inlead-lead collisionsat √sNN=2.76 TeVwiththe ATLAS detector atthe

LHC,Phys.Rev.Lett.105(2010)252303,https://doi.org/10.1103/PhysRevLett. 105.252303,arXiv:1011.6182.

[8] A.Andronic,etal.,Heavy-flavourandquarkoniumproductionintheLHCera: from proton-protonto heavy-ion collisions, Eur. Phys. J. C 76 (2016) 107,

https://doi.org/10.1140/epjc/s10052-015-3819-5,arXiv:1506.03981.

[9] J.Rafelski,B.Müller,Strangenessproductioninthequark- gluonplasma,Phys. Rev.Lett. 48 (1982)1066, https://doi.org/10.1103/PhysRevLett.48.1066, Erra-tum:https://doi.org/10.1103/PhysRevLett.56.2334.

[10] G.Agakishiev,etal.,STARCollaboration,StrangenessenhancementinCu+Cu andAu+Aucollisionsat√sNN=200 GeV,Phys.Rev.Lett.108(2012)072301, https://doi.org/10.1103/PhysRevLett.108.072301,arXiv:1107.2955.

[11] B.I.Abelev,etal.,STARCollaboration,Energyandsystemsizedependenceof phimesonproductioninCu+CuandAu+Aucollisions,Phys.Lett.B673(2009) 183,https://doi.org/10.1016/j.physletb.2009.02.037,arXiv:0810.4979. [12] I.C.Arsene,etal.,BRAHMSCollaboration,Kaonandpionproductionincentral

Au+Aucollisionsat√sNN=62.4 GeV,Phys.Lett.B687(2010) 36,https:// doi.org/10.1016/j.physletb.2010.02.078,arXiv:0911.2586.

[13] L.Adamczyk,etal.,STARCollaboration,Collisionenergydependenceof mo-mentsofnet-kaonmultiplicitydistributionsatRHIC,Phys.Lett.B785(2018) 551,https://doi.org/10.1016/j.physletb.2018.07.066,arXiv:1709.00773. [14] A. Adare, et al., PHENIX Collaboration, φ meson production in the

for-ward/backwardrapidityregioninCu+Aucollisionsat√sNN=200 GeV,Phys.

Rev.C93(2016) 024904,https://doi.org/10.1103/PhysRevC.93.024904,arXiv: 1509.06337.

[15] ALICE Collaboration,Enhancedproductionofmulti-strangehadronsin high-multiplicityproton-protoncollisions,Nat.Phys.13(2017)535,https://doi.org/ 10.1038/nphys4111,arXiv:1606.07424.

[16] ALICECollaboration,K0

SandproductioninPb-Pbcollisionsat

√

sN N=2.76 TeV, Phys.Rev.Lett.111(2013)222301, https://doi.org/10.1103/PhysRevLett. 111.222301,arXiv:1307.5530.

[17] M.He, R.J. Fries, R. Rapp,Heavy flavor at the large hadron collider in a strongcouplingapproach,Phys.Lett.B735(2014)445,https://doi.org/10.1016/ j.physletb.2014.05.050,arXiv:1401.3817.

[18] D. Molnar, S.A. Voloshin, Elliptic flow at large transverse momenta from quarkcoalescence,Phys.Rev.Lett.91(2003)092301,https://doi.org/10.1103/ PhysRevLett.91.092301,arXiv:nucl-th/0302014.

[19] V.Greco,C.M.Ko,P.Levai,PartoncoalescenceatRHIC,Phys.Rev.C68(2003) 034904,https://doi.org/10.1103/PhysRevC.68.034904,arXiv:nucl-th/0305024. [20] V.Greco,C.M.Ko,R.Rapp,Quarkcoalescenceforcharmedmesonsin

ultrarel-ativisticheavyioncollisions,Phys.Lett.B595(2004)202,https://doi.org/10. 1016/j.physletb.2004.06.064,arXiv:nucl-th/0312100.

[21] ALICECollaboration,MeasurementofD0_,D+_,D∗+_andD+

s productioninPb-Pb

collisionsat √sNN=5.02 TeV,J.HighEnergy Phys.10(2018) 174,https:// doi.org/10.1007/JHEP10(2018)174,arXiv:1804.09083.

[22] CMSCollaboration,MeasurementoftheB0

sproductioncrosssectionwithB0s→

J/ψφ decaysinp pcollisionsat√s=7 TeV,Phys.Rev.D84(2011)052008,

https://doi.org/10.1103/PhysRevD.84.052008,arXiv:1106.4048.

[23] CMSCollaboration,StudyofB mesonproductioninp+Pbcollisionsat√sNN=

5.02 TeVusingexclusivehadronicdecays,Phys.Rev.Lett.116(2016)032301,

https://doi.org/10.1103/PhysRevLett.116.032301,arXiv:1508.06678.

[24] M.Cacciari,M.Greco,P.Nason,ThepTspectruminheavy-flavour

hadropro-duction, J. High Energy Phys. 05 (1998) 007, https://doi.org/10.1088/1126 -6708/1998/05/007,arXiv:hep-ph/9803400.

[25] M.Cacciari,P.Nason, Charmcrosssectionsfor theTevatron RunII,J. High Energy Phys. 09(2003)006,https://doi.org/10.1088/1126-6708/2003/09/006, arXiv:hep-ph/0306212.

[26] M.Cacciari,S.Frixione,N.Houdeau,M.L.Mangano,P.Nason,G.Ridolfi, The-oretical predictions for charm and bottom production at the LHC, J. High Energy Phys. 10(2012)137,https://doi.org/10.1007/JHEP10(2012)137, arXiv: 1205.6344.

[27] CMSCollaboration,MeasurementoftheB±mesonnuclearmodificationfactor inPb-Pbcollisionsat √sNN=5.02 TeV, Phys.Rev.Lett.119(2017)152301, https://doi.org/10.1103/PhysRevLett.119.152301,arXiv:1705.04727.

[28] C.Patrignani,etal.,ParticleDataGroup,Reviewofparticlephysics,Chin.Phys. C40(2016)100001,https://doi.org/10.1088/1674-1137/40/10/100001. [29] CMSCollaboration,Descriptionandperformanceoftrackandprimary-vertex

reconstructionwiththeCMStracker,J.Instrum.9(2014)P10009,https://doi. org/10.1088/1748-0221/9/10/P10009,arXiv:1405.6569.

[30] CMSCollaboration,PerformanceofCMSmuonreconstructioninppcollision eventsat √s=7 TeV,J. Instrum.7(2012)P10002, https://doi.org/10.1088/ 1748-0221/7/10/P10002,arXiv:1206.4071.

[31] CMSCollaboration,TheCMSexperimentattheCERNLHC,J.Instrum.3(2008) S08004,https://doi.org/10.1088/1748-0221/3/08/S08004.

[32] T.Sjöstrand, S.Ask,J.R.Christiansen,R.Corke, N.Desai,P.Ilten,S.Mrenna, S.Prestel,C.O.Rasmussen,P.Z.Skands,AnintroductiontoPYTHIA8.2,

Com-put.Phys.Commun.191(2015)159,https://doi.org/10.1016/j.cpc.2015.01.024, arXiv:1410.3012.

[33] CMSCollaboration,Eventgeneratortunesobtainedfromunderlyingeventand multipartonscatteringmeasurements,Eur.Phys.J.C76(2016),https://doi.org/ 10.1140/epjc/s10052-016-3988-x,arXiv:1512.00815.

[34] J.Allison,etal.,RecentdevelopmentsinGeant4,Nucl.Instrum.MethodsA835 (2016)186,https://doi.org/10.1016/j.nima.2016.06.125.

[35] D.J.Lange,TheEvtGenparticledecaysimulationpackage,Nucl.Instrum. Meth-odsA462(2001)152,https://doi.org/10.1016/S0168-9002(01)00089-4. [36] E.Barberio,B.vanEijk,Z.Was,PHOTOS:auniversalMonteCarloforQED

ra-diativecorrectionsindecays,Comput.Phys.Commun.66(1991)115,https:// doi.org/10.1016/0010-4655(91)90012-A.

[37] I.P.Lokhtin,A.M.Snigirev,Amodelofjetquenchinginultrarelativisticheavy ioncollisionsand high-pThadronspectraatRHIC,Eur.Phys. J.C45(2006)

211,https://doi.org/10.1140/epjc/s2005-02426-3,arXiv:hep-ph/0506189. [38] CMSCollaboration,Charged-particlenuclearmodificationfactorsinPbPband

pPbcollisionsat√sNN=5.02 TeV,J.HighEnergyPhys.04(2017)039,https:// doi.org/10.1007/JHEP04(2017)039,arXiv:1611.01664.

[39] CMSCollaboration,Transversemomentumandpseudorapiditydistributionsof chargedhadronsinppcollisionsat√s=0.9 and2.76TeV,J.HighEnergyPhys. 02(2010)041,https://doi.org/10.1007/JHEP02(2010)041,arXiv:1002.0621. [40] CMS_√ Collaboration,CMSluminositycalibrationfor theppreferencerun at

s=5.02 TeV,CMSPhysicsAnalysisSummaryCMS-PAS-LUM-16-001,2016,

https://cds.cern.ch/record/2235781.

[41] ParticleDataGroup,M.Tanabashi,etal.,Reviewofparticlephysics,Phys.Rev. D98(2018)030001,https://doi.org/10.1103/PhysRevD.98.030001.

[42] H.Voss,A.Höcker,J.Stelzer,F.Tegenfeldt,TMVA–thetoolkitformultivariate dataanalysis,in:XIthInternationalWorkshop onAdvancedComputingand AnalysisTechniquesinPhysicsResearch(ACAT),2009,p. 40,http://pos.sissa.it/ archive/conferences/050/040/ACAT_040.pdf,arXiv:physics/0703039.

[43] M.L.Miller,K. Reygers,S.J.Sanders,P.Steinberg,Glaubermodelingin high-energynuclearcollisions,Annu.Rev.Nucl.Part.Sci.57(2007)205,https:// doi.org/10.1146/annurev.nucl.57.090506.123020,arXiv:nucl-ex/0701025. [44] CMSCollaboration,MeasurementsofinclusiveWandZcrosssectionsinpp

collisionsat√s=7 TeV,J.HighEnergyPhys.01(2011)080,https://doi.org/10. 1007/JHEP01(2011)080,arXiv:1012.2466.

[45] J.Xu,J. Liao,M.Gyulassy,Bridging soft-hardtransportproperties of quark-gluonplasmaswith CUJET3.0, J.High Energy Phys. 02(2016) 169,https:// doi.org/10.1007/JHEP02(2016)169,arXiv:1508.00552.

[46] J.Xu,J.Liao, M.Gyulassy,Consistencyofperfectfluidityand jetquenching insemi-quark-gluonmonopole plasmas,Chin.Phys. Lett.32(2015)092501,

https://doi.org/10.1088/0256-307X/32/9/092501,arXiv:1411.3673.

[47] J.Xu,A.Buzzatti,M.Gyulassy,AzimuthaljetflavortomographywithCUJET2.0 ofnuclearcollisionsatRHICand LHC,J.HighEnergy Phys. 08(2014)063,

https://doi.org/10.1007/JHEP08(2014)063,arXiv:1402.2956.

[48] M.He,R.J.Fries,R.Rapp,Heavy-quarkdiffusionandhadronizationin quark-gluonplasma,Phys.Rev.C86(2012)014903,https://doi.org/10.1103/PhysRevC. 86.014903,arXiv:1106.6006.

TheCMSCollaboration

A.M. Sirunyan,A. Tumasyan

YerevanPhysicsInstitute,Yerevan,Armenia

W. Adam, F. Ambrogi, E. Asilar,T. Bergauer, J. Brandstetter, M. Dragicevic,J. Erö,A. Escalante Del Valle, M. Flechl,R. Frühwirth1, V.M. Ghete, J. Hrubec, M. Jeitler1, N. Krammer,I. Krätschmer,D. Liko,

T. Madlener, I. Mikulec,N. Rad, H. Rohringer, J. Schieck1,R. Schöfbeck, M. Spanring, D. Spitzbart,

A. Taurok,W. Waltenberger, J. Wittmann, C.-E. Wulz1, M. Zarucki

InstitutfürHochenergiephysik,Wien,Austria

V. Chekhovsky, V. Mossolov,J. Suarez Gonzalez

InstituteforNuclearProblems,Minsk,Belarus

E.A. De Wolf,D. Di Croce, X. Janssen, J. Lauwers,M. Pieters,H. Van Haevermaet, P. Van Mechelen,

N. Van Remortel

S. Abu Zeid,F. Blekman, J. D’Hondt, I. De Bruyn, J. De Clercq, K. Deroover, G. Flouris, D. Lontkovskyi,

S. Lowette,I. Marchesini, S. Moortgat, L. Moreels,Q. Python, K. Skovpen, S. Tavernier,W. Van Doninck,

P. Van Mulders,I. Van Parijs

VrijeUniversiteitBrussel,Brussel,Belgium

D. Beghin,B. Bilin, H. Brun, B. Clerbaux, G. De Lentdecker,H. Delannoy, B. Dorney, G. Fasanella,L. Favart,

R. Goldouzian, A. Grebenyuk,A.K. Kalsi,T. Lenzi, J. Luetic, N. Postiau,E. Starling, L. Thomas,

C. Vander Velde, P. Vanlaer,D. Vannerom, Q. Wang

UniversitéLibredeBruxelles,Bruxelles,Belgium

T. Cornelis,D. Dobur, A. Fagot,M. Gul, I. Khvastunov2,D. Poyraz, C. Roskas, D. Trocino, M. Tytgat,

W. Verbeke,B. Vermassen, M. Vit, N. Zaganidis

GhentUniversity,Ghent,Belgium

H. Bakhshiansohi,O. Bondu, S. Brochet,G. Bruno, C. Caputo, P. David,C. Delaere, M. Delcourt,

B. Francois,A. Giammanco, G. Krintiras,V. Lemaitre, A. Magitteri, A. Mertens, M. Musich,

K. Piotrzkowski,A. Saggio, M. Vidal Marono, S. Wertz, J. Zobec

UniversitéCatholiquedeLouvain,Louvain-la-Neuve,Belgium

F.L. Alves,G.A. Alves,M. Correa Martins Junior, G. Correia Silva,C. Hensel, A. Moraes,M.E. Pol, P. Rebello Teles

CentroBrasileirodePesquisasFisicas,RiodeJaneiro,Brazil

E. Belchior Batista Das Chagas, W. Carvalho,J. Chinellato3, E. Coelho, E.M. Da Costa, G.G. Da Silveira4,

D. De Jesus Damiao,C. De Oliveira Martins, S. Fonseca De Souza, H. Malbouisson, D. Matos Figueiredo,

M. Melo De Almeida,C. Mora Herrera,L. Mundim, H. Nogima,W.L. Prado Da Silva, L.J. Sanchez Rosas,

A. Santoro,A. Sznajder, M. Thiel, E.J. Tonelli Manganote3,F. Torres Da Silva De Araujo, A. Vilela Pereira

UniversidadedoEstadodoRiodeJaneiro,RiodeJaneiro,Brazil

S. Ahujaa,C.A. Bernardesa, L. Calligarisa,T.R. Fernandez Perez Tomeia,E.M. Gregoresb, P.G. Mercadanteb,S.F. Novaesa,Sandra Padulaa

a_{UniversidadeEstadualPaulista,SãoPaulo,Brazil} b_{UniversidadeFederaldoABC,SãoPaulo,Brazil}

A. Aleksandrov, R. Hadjiiska,P. Iaydjiev, A. Marinov, M. Misheva, M. Rodozov,M. Shopova, G. Sultanov

InstituteforNuclearResearchandNuclearEnergy,BulgarianAcademyofSciences,Sofia,Bulgaria

A. Dimitrov,L. Litov, B. Pavlov,P. Petkov

UniversityofSofia,Sofia,Bulgaria

W. Fang5, X. Gao5,L. Yuan

BeihangUniversity,Beijing,China

M. Ahmad, J.G. Bian, G.M. Chen,H.S. Chen, M. Chen, Y. Chen, C.H. Jiang, D. Leggat,H. Liao, Z. Liu,

F. Romeo,S.M. Shaheen6,A. Spiezia, J. Tao, Z. Wang, E. Yazgan, H. Zhang,S. Zhang6,J. Zhao

InstituteofHighEnergyPhysics,Beijing,China

Y. Ban, G. Chen, A. Levin,J. Li, L. Li,Q. Li, Y. Mao, S.J. Qian, D. Wang,Z. Xu

Y. Wang

TsinghuaUniversity,Beijing,China

C. Avila,A. Cabrera, C.A. Carrillo Montoya, L.F. Chaparro Sierra, C. Florez, C.F. González Hernández,

M.A. Segura Delgado

UniversidaddeLosAndes,Bogota,Colombia

B. Courbon, N. Godinovic, D. Lelas,I. Puljak, T. Sculac

UniversityofSplit,FacultyofElectricalEngineering,MechanicalEngineeringandNavalArchitecture,Split,Croatia

Z. Antunovic, M. Kovac

UniversityofSplit,FacultyofScience,Split,Croatia

V. Brigljevic,D. Ferencek, K. Kadija,B. Mesic, A. Starodumov7, T. Susa

InstituteRudjerBoskovic,Zagreb,Croatia

M.W. Ather,A. Attikis, M. Kolosova, G. Mavromanolakis,J. Mousa, C. Nicolaou, F. Ptochos, P.A. Razis,

H. Rykaczewski

UniversityofCyprus,Nicosia,Cyprus

M. Finger8, M. Finger Jr.8

CharlesUniversity,Prague,CzechRepublic

E. Ayala

EscuelaPolitecnicaNacional,Quito,Ecuador

E. Carrera Jarrin

UniversidadSanFranciscodeQuito,Quito,Ecuador

A. Ellithi Kamel9, M.A. Mahmoud10,11,Y. Mohammed10

AcademyofScientificResearchandTechnologyoftheArabRepublicofEgypt,EgyptianNetworkofHighEnergyPhysics,Cairo,Egypt

S. Bhowmik, A. Carvalho Antunes De Oliveira,R.K. Dewanjee, K. Ehataht, M. Kadastik, M. Raidal,

C. Veelken

NationalInstituteofChemicalPhysicsandBiophysics,Tallinn,Estonia

P. Eerola, H. Kirschenmann,J. Pekkanen,M. Voutilainen

DepartmentofPhysics,UniversityofHelsinki,Helsinki,Finland

J. Havukainen, J.K. Heikkilä, T. Järvinen,V. Karimäki, R. Kinnunen, T. Lampén, K. Lassila-Perini,S. Laurila,

S. Lehti, T. Lindén,P. Luukka, T. Mäenpää, H. Siikonen,E. Tuominen, J. Tuominiemi

HelsinkiInstituteofPhysics,Helsinki,Finland

T. Tuuva

LappeenrantaUniversityofTechnology,Lappeenranta,Finland

M. Besancon, F. Couderc,M. Dejardin, D. Denegri, J.L. Faure, F. Ferri, S. Ganjour, A. Givernaud, P. Gras,

G. Hamel de Monchenault, P. Jarry,C. Leloup,E. Locci, J. Malcles,G. Negro, J. Rander, A. Rosowsky,

M.Ö. Sahin,M. Titov

A. Abdulsalam12,C. Amendola, I. Antropov, F. Beaudette, P. Busson, C. Charlot, R. Granier de Cassagnac,

I. Kucher, A. Lobanov, J. Martin Blanco, C. Martin Perez,M. Nguyen, C. Ochando, G. Ortona, P. Paganini,

P. Pigard,J. Rembser, R. Salerno,J.B. Sauvan, Y. Sirois, A.G. Stahl Leiton, A. Zabi,A. Zghiche

LaboratoireLeprince-Ringuet,Ecolepolytechnique,CNRS/IN2P3,UniversitéParis-Saclay,Palaiseau,France

J.-L. Agram13,J. Andrea, D. Bloch,J.-M. Brom, E.C. Chabert,V. Cherepanov, C. Collard, E. Conte13, J.-C. Fontaine13,D. Gelé, U. Goerlach,M. Jansová, A.-C. Le Bihan, N. Tonon,P. Van Hove

UniversitédeStrasbourg,CNRS,IPHCUMR7178,Strasbourg,France

S. Gadrat

CentredeCalculdel’InstitutNationaldePhysiqueNucleaireetdePhysiquedesParticules,CNRS/IN2P3,Villeurbanne,France

S. Beauceron,C. Bernet, G. Boudoul,N. Chanon, R. Chierici,D. Contardo, P. Depasse, H. El Mamouni,

J. Fay, L. Finco,S. Gascon, M. Gouzevitch, G. Grenier, B. Ille, F. Lagarde, I.B. Laktineh,H. Lattaud, M. Lethuillier,L. Mirabito, S. Perries,A. Popov14,V. Sordini, G. Touquet, M. Vander Donckt, S. Viret

UniversitédeLyon,UniversitéClaudeBernardLyon1,CNRS-IN2P3,InstitutdePhysiqueNucléairedeLyon,Villeurbanne,France

T. Toriashvili15

GeorgianTechnicalUniversity,Tbilisi,Georgia

I. Bagaturia16

TbilisiStateUniversity,Tbilisi,Georgia

C. Autermann,L. Feld, M.K. Kiesel, K. Klein, M. Lipinski,M. Preuten, M.P. Rauch,C. Schomakers, J. Schulz,

M. Teroerde,B. Wittmer, V. Zhukov14

RWTHAachenUniversity,I.PhysikalischesInstitut,Aachen,Germany

A. Albert, D. Duchardt, M. Erdmann,S. Erdweg, T. Esch, R. Fischer,S. Ghosh, A. Güth, T. Hebbeker,

C. Heidemann,K. Hoepfner,H. Keller, L. Mastrolorenzo,M. Merschmeyer, A. Meyer,P. Millet,

S. Mukherjee,T. Pook,M. Radziej, H. Reithler, M. Rieger, A. Schmidt,D. Teyssier, S. Thüer

RWTHAachenUniversity,III.PhysikalischesInstitutA,Aachen,Germany

G. Flügge,O. Hlushchenko, T. Kress, A. Künsken, T. Müller,A. Nehrkorn, A. Nowack, C. Pistone, O. Pooth,

D. Roy, H. Sert, A. Stahl17

RWTHAachenUniversity,III.PhysikalischesInstitutB,Aachen,Germany

M. Aldaya Martin,T. Arndt, C. Asawatangtrakuldee, I. Babounikau, K. Beernaert,O. Behnke, U. Behrens,

A. Bermúdez Martínez, D. Bertsche, A.A. Bin Anuar, K. Borras18,V. Botta, A. Campbell,P. Connor,

C. Contreras-Campana, V. Danilov,A. De Wit, M.M. Defranchis, C. Diez Pardos, D. Domínguez Damiani,

G. Eckerlin,T. Eichhorn, A. Elwood, E. Eren, E. Gallo19, A. Geiser, A. Grohsjean, M. Guthoff,M. Haranko,

A. Harb,J. Hauk, H. Jung,M. Kasemann, J. Keaveney, C. Kleinwort,J. Knolle, D. Krücker, W. Lange,

A. Lelek,T. Lenz, J. Leonard, K. Lipka,W. Lohmann20, R. Mankel, I.-A. Melzer-Pellmann,A.B. Meyer,

M. Meyer,M. Missiroli, G. Mittag, J. Mnich, V. Myronenko,S.K. Pflitsch, D. Pitzl,A. Raspereza,

M. Savitskyi,P. Saxena,P. Schütze, C. Schwanenberger, R. Shevchenko, A. Singh,H. Tholen, O. Turkot,

A. Vagnerini,G.P. Van Onsem, R. Walsh, Y. Wen,K. Wichmann,C. Wissing, O. Zenaiev

DeutschesElektronen-Synchrotron,Hamburg,Germany

R. Aggleton,S. Bein, L. Benato, A. Benecke, V. Blobel, T. Dreyer, E. Garutti,D. Gonzalez, P. Gunnellini,

J. Haller, A. Hinzmann, A. Karavdina,G. Kasieczka, R. Klanner, R. Kogler,N. Kovalchuk, S. Kurz,

A. Reimers, O. Rieger,C. Scharf, P. Schleper, S. Schumann, J. Schwandt, J. Sonneveld,H. Stadie,

G. Steinbrück, F.M. Stober,M. Stöver, A. Vanhoefer, B. Vormwald, I. Zoi

UniversityofHamburg,Hamburg,Germany

M. Akbiyik, C. Barth,M. Baselga, S. Baur, E. Butz,R. Caspart, T. Chwalek, F. Colombo, W. De Boer,

A. Dierlamm, K. El Morabit,N. Faltermann, B. Freund,M. Giffels, M.A. Harrendorf,F. Hartmann17,

S.M. Heindl,U. Husemann, F. Kassel17,I. Katkov14, S. Kudella, H. Mildner, S. Mitra, M.U. Mozer, Th. Müller, M. Plagge, G. Quast, K. Rabbertz,M. Schröder, I. Shvetsov, G. Sieber,H.J. Simonis, R. Ulrich,

S. Wayand,M. Weber, T. Weiler, S. Williamson, C. Wöhrmann, R. Wolf

KarlsruherInstitutfuerTechnologie,Karlsruhe,Germany

G. Anagnostou, G. Daskalakis,T. Geralis,A. Kyriakis, D. Loukas, G. Paspalaki,I. Topsis-Giotis

InstituteofNuclearandParticlePhysics(INPP),NCSRDemokritos,AghiaParaskevi,Greece

G. Karathanasis,S. Kesisoglou, P. Kontaxakis, A. Panagiotou, I. Papavergou, N. Saoulidou, E. Tziaferi, K. Vellidis

NationalandKapodistrianUniversityofAthens,Athens,Greece

K. Kousouris,I. Papakrivopoulos, G. Tsipolitis

NationalTechnicalUniversityofAthens,Athens,Greece

I. Evangelou, C. Foudas,P. Gianneios, P. Katsoulis, P. Kokkas, S. Mallios,N. Manthos, I. Papadopoulos, E. Paradas, J. Strologas,F.A. Triantis, D. Tsitsonis

UniversityofIoánnina,Ioánnina,Greece

M. Bartók21,M. Csanad, N. Filipovic, P. Major, M.I. Nagy, G. Pasztor, O. Surányi,G.I. Veres

MTA-ELTELendületCMSParticleandNuclearPhysicsGroup,EötvösLorándUniversity,Budapest,Hungary

G. Bencze,C. Hajdu, D. Horvath22,Á. Hunyadi, F. Sikler,T.Á. Vámi, V. Veszpremi, G. Vesztergombi†

WignerResearchCentreforPhysics,Budapest,Hungary

N. Beni, S. Czellar, J. Karancsi23,A. Makovec, J. Molnar,Z. Szillasi

InstituteofNuclearResearchATOMKI,Debrecen,Hungary

P. Raics, Z.L. Trocsanyi,B. Ujvari

InstituteofPhysics,UniversityofDebrecen,Debrecen,Hungary

S. Choudhury, J.R. Komaragiri, P.C. Tiwari

IndianInstituteofScience(IISc),Bangalore,India

S. Bahinipati24, C. Kar,P. Mal, K. Mandal, A. Nayak25,D.K. Sahoo24,S.K. Swain

NationalInstituteofScienceEducationandResearch,HBNI,Bhubaneswar,India

S. Bansal, S.B. Beri,V. Bhatnagar, S. Chauhan,R. Chawla, N. Dhingra, R. Gupta, A. Kaur, M. Kaur, S. Kaur,

R. Kumar,P. Kumari, M. Lohan, A. Mehta, K. Sandeep, S. Sharma,J.B. Singh, A.K. Virdi, G. Walia

PanjabUniversity,Chandigarh,India

A. Bhardwaj,B.C. Choudhary, R.B. Garg, M. Gola,S. Keshri, Ashok Kumar, S. Malhotra,M. Naimuddin,

P. Priyanka, K. Ranjan,Aashaq Shah, R. Sharma

R. Bhardwaj26, M. Bharti26, R. Bhattacharya,S. Bhattacharya, U. Bhawandeep26, D. Bhowmik, S. Dey,

S. Dutt26,S. Dutta, S. Ghosh, K. Mondal, S. Nandan, A. Purohit,P.K. Rout, A. Roy,S. Roy Chowdhury,

G. Saha,S. Sarkar, M. Sharan, B. Singh26, S. Thakur26

SahaInstituteofNuclearPhysics,HBNI,Kolkata,India

P.K. Behera

IndianInstituteofTechnologyMadras,Madras,India

R. Chudasama, D. Dutta, V. Jha, V. Kumar, P.K. Netrakanti, L.M. Pant, P. Shukla

BhabhaAtomicResearchCentre,Mumbai,India

T. Aziz,M.A. Bhat, S. Dugad, G.B. Mohanty, N. Sur, B. Sutar, R.K. Verma

TataInstituteofFundamentalResearch-A,Mumbai,India

S. Banerjee, S. Bhattacharya, S. Chatterjee,P. Das, M. Guchait,Sa. Jain, S. Karmakar, S. Kumar,

M. Maity27,G. Majumder, K. Mazumdar, N. Sahoo,T. Sarkar27

TataInstituteofFundamentalResearch-B,Mumbai,India

S. Chauhan,S. Dube, V. Hegde, A. Kapoor, K. Kothekar, S. Pandey, A. Rane, S. Sharma

IndianInstituteofScienceEducationandResearch(IISER),Pune,India

S. Chenarani28, E. Eskandari Tadavani,S.M. Etesami28, M. Khakzad, M. Mohammadi Najafabadi,

M. Naseri, F. Rezaei Hosseinabadi, B. Safarzadeh29, M. Zeinali

InstituteforResearchinFundamentalSciences(IPM),Tehran,Iran

M. Felcini,M. Grunewald

UniversityCollegeDublin,Dublin,Ireland

M. Abbresciaa,b, C. Calabriaa,b, A. Colaleoa, D. Creanzaa,c,L. Cristellaa,b, N. De Filippisa,c,

M. De Palmaa,b, A. Di Florioa,b, F. Erricoa,b,L. Fiorea,A. Gelmia,b, G. Iasellia,c, M. Incea,b,S. Lezkia,b, G. Maggia,c, M. Maggia,G. Minielloa,b,S. Mya,b,S. Nuzzoa,b, A. Pompilia,b, G. Pugliesea,c,R. Radognaa, A. Ranieria,G. Selvaggia,b,A. Sharmaa,L. Silvestrisa, R. Vendittia,P. Verwilligena,G. Zitoa

a_{INFNSezionediBari,Bari,Italy} b_{UniversitàdiBari,Bari,Italy} c_{PolitecnicodiBari,Bari,Italy}

G. Abbiendia,C. Battilanaa,b,D. Bonacorsia,b, L. Borgonovia,b,S. Braibant-Giacomellia,b,

R. Campaninia,b,P. Capiluppia,b,A. Castroa,b, F.R. Cavalloa, S.S. Chhibraa,b,C. Cioccaa,G. Codispotia,b, M. Cuffiania,b,G.M. Dallavallea, F. Fabbria,A. Fanfania,b,E. Fontanesi, P. Giacomellia,C. Grandia, L. Guiduccia,b,S. Lo Meoa,S. Marcellinia, G. Masettia, A. Montanaria, F.L. Navarriaa,b,A. Perrottaa, F. Primaveraa,b,17_{,A.M. Rossi}a,b_{, T. Rovelli}a,b_{,G.P. Siroli}a,b_{, N. Tosi}a

a_{INFNSezionediBologna,Bologna,Italy} b_{UniversitàdiBologna,Bologna,Italy}

S. Albergoa,b, A. Di Mattiaa,R. Potenzaa,b,A. Tricomia,b,C. Tuvea,b

a_{INFNSezionediCatania,Catania,Italy} b_{UniversitàdiCatania,Catania,Italy}

G. Barbaglia,K. Chatterjeea,b,V. Ciullia,b,C. Civininia,R. D’Alessandroa,b, E. Focardia,b, G. Latino, P. Lenzia,b, M. Meschinia, S. Paolettia,L. Russoa,30, G. Sguazzonia,D. Stroma,L. Viliania

a_{INFNSezionediFirenze,Firenze,Italy} b_{UniversitàdiFirenze,Firenze,Italy}

L. Benussi, S. Bianco, F. Fabbri,D. Piccolo

INFNLaboratoriNazionalidiFrascati,Frascati,Italy

F. Ferroa, F. Raveraa,b,E. Robuttia, S. Tosia,b

a_{INFNSezionediGenova,Genova,Italy} b_{UniversitàdiGenova,Genova,Italy}

A. Benagliaa, A. Beschib, L. Brianzaa,b, F. Brivioa,b, V. Cirioloa,b,17,S. Di Guidaa,b,17, M.E. Dinardoa,b, S. Fiorendia,b,S. Gennaia,A. Ghezzia,b,P. Govonia,b,M. Malbertia,b, S. Malvezzia, A. Massironia,b, D. Menascea,F. Monti, L. Moronia,M. Paganonia,b_{, D. Pedrini}a_{,S. Ragazzi}a,b_{,T. Tabarelli de Fatis}a,b_,

D. Zuoloa,b

a_{INFNSezionediMilano-Bicocca,Milano,Italy} b_{UniversitàdiMilano-Bicocca,Milano,Italy}

S. Buontempoa, N. Cavalloa,c, A. De Iorioa,b,A. Di Crescenzoa,b, F. Fabozzia,c,F. Fiengaa, G. Galatia, A.O.M. Iorioa,b, W.A. Khana,L. Listaa, S. Meolaa,d,17, P. Paoluccia,17, C. Sciaccaa,b, E. Voevodinaa,b

a_{INFNSezionediNapoli,Napoli,Italy} b_{UniversitàdiNapoli‘FedericoII’,Napoli,Italy} c_{UniversitàdellaBasilicata,Potenza,Italy} d_{UniversitàG.Marconi,Roma,Italy}

P. Azzia,N. Bacchettaa,D. Biselloa,b,A. Bolettia,b,A. Bragagnolo,R. Carlina,b, P. Checchiaa, M. Dall’Ossoa,b,P. De Castro Manzanoa, T. Dorigoa,U. Dossellia,F. Gasparinia,b,U. Gasparinia,b, A. Gozzelinoa, S.Y. Hoh, S. Lacapraraa,P. Lujan, M. Margonia,b, A.T. Meneguzzoa,b,J. Pazzinia,b,

P. Ronchesea,b,R. Rossina,b,F. Simonettoa,b,A. Tiko, E. Torassaa,M. Zanettia,b,P. Zottoa,b,G. Zumerlea,b

a_{INFNSezionediPadova,Padova,Italy} b_{UniversitàdiPadova,Padova,Italy} c_{UniversitàdiTrento,Trento,Italy}

A. Braghieria,A. Magnania,P. Montagnaa,b, S.P. Rattia,b,V. Rea, M. Ressegottia,b, C. Riccardia,b, P. Salvinia, I. Vaia,b, P. Vituloa,b

a_{INFNSezionediPavia,Pavia,Italy} b_{UniversitàdiPavia,Pavia,Italy}

M. Biasinia,b, G.M. Bileia,C. Cecchia,b,D. Ciangottinia,b,L. Fanòa,b,P. Laricciaa,b, R. Leonardia,b, E. Manonia, G. Mantovania,b, V. Mariania,b,M. Menichellia,A. Rossia,b,A. Santocchiaa,b, D. Spigaa

a_{INFNSezionediPerugia,Perugia,Italy} b_{UniversitàdiPerugia,Perugia,Italy}

K. Androsova,P. Azzurria,G. Bagliesia,L. Bianchinia,T. Boccalia,L. Borrello, R. Castaldia, M.A. Cioccia,b, R. Dell’Orsoa,G. Fedia, F. Fioria,c, L. Gianninia,c,A. Giassia, M.T. Grippoa,F. Ligabuea,c, E. Mancaa,c, G. Mandorlia,c, A. Messineoa,b, F. Pallaa,A. Rizzia,b, P. Spagnoloa, R. Tenchinia,G. Tonellia,b,

A. Venturia, P.G. Verdinia

a_{INFNSezionediPisa,Pisa,Italy} b_{UniversitàdiPisa,Pisa,Italy}

c_{ScuolaNormaleSuperiorediPisa,Pisa,Italy}

L. Baronea,b,F. Cavallaria, M. Cipriania,b,D. Del Rea,b, E. Di Marcoa,b, M. Diemoza,S. Gellia,b,

E. Longoa,b, B. Marzocchia,b,P. Meridiania, G. Organtinia,b,F. Pandolfia, R. Paramattia,b, F. Preiatoa,b, S. Rahatloua,b,C. Rovellia,F. Santanastasioa,b

a_{INFNSezionediRoma,Rome,Italy} b_{SapienzaUniversitàdiRoma,Rome,Italy}

N. Amapanea,b_{, R. Arcidiacono}a,c_{,S. Argiro}a,b_{,M. Arneodo}a,c_{,N. Bartosik}a_{,R. Bellan}a,b_{, C. Biino}a_,

N. Cartigliaa, F. Cennaa,b,S. Comettia,M. Costaa,b, R. Covarellia,b,N. Demariaa,B. Kiania,b,C. Mariottia, S. Masellia, E. Migliorea,b,V. Monacoa,b,E. Monteila,b,M. Montenoa, M.M. Obertinoa,b,L. Pachera,b,

N. Pastronea,M. Pelliccionia,G.L. Pinna Angionia,b, A. Romeroa,b, M. Ruspaa,c,R. Sacchia,b, K. Shchelinaa,b, V. Solaa,A. Solanoa,b,D. Soldia,b,A. Staianoa

a_{INFNSezionediTorino,Torino,Italy} b_{UniversitàdiTorino,Torino,Italy}

c_{UniversitàdelPiemonteOrientale,Novara,Italy}

S. Belfortea,V. Candelisea,b, M. Casarsaa,F. Cossuttia,A. Da Rolda,b,G. Della Riccaa,b,F. Vazzolera,b, A. Zanettia

a_{INFNSezionediTrieste,Trieste,Italy} b_{UniversitàdiTrieste,Trieste,Italy}

D.H. Kim,G.N. Kim, M.S. Kim, J. Lee,S. Lee, S.W. Lee, C.S. Moon, Y.D. Oh, S.I. Pak,S. Sekmen, D.C. Son, Y.C. Yang

KyungpookNationalUniversity,Daegu,RepublicofKorea

H. Kim,D.H. Moon,G. Oh

ChonnamNationalUniversity,InstituteforUniverseandElementaryParticles,Kwangju,RepublicofKorea

J. Goh31, T.J. Kim

HanyangUniversity,Seoul,RepublicofKorea

S. Cho,S. Choi, Y. Go, D. Gyun,S. Ha,B. Hong, Y. Jo,K. Lee, K.S. Lee, S. Lee, J. Lim, S.K. Park,Y. Roh

KoreaUniversity,Seoul,RepublicofKorea

H.S. Kim

SejongUniversity,Seoul,RepublicofKorea

J. Almond,J. Kim, J.S. Kim, H. Lee,K. Lee, K. Nam,S.B. Oh, B.C. Radburn-Smith, S.h. Seo, U.K. Yang,

H.D. Yoo,G.B. Yu

SeoulNationalUniversity,Seoul,RepublicofKorea

D. Jeon, H. Kim,J.H. Kim, J.S.H. Lee, I.C. Park

UniversityofSeoul,Seoul,RepublicofKorea

Y. Choi,C. Hwang, J. Lee,I. Yu

SungkyunkwanUniversity,Suwon,RepublicofKorea

V. Dudenas, A. Juodagalvis,J. Vaitkus

VilniusUniversity,Vilnius,Lithuania

I. Ahmed,Z.A. Ibrahim, M.A.B. Md Ali32,F. Mohamad Idris33,W.A.T. Wan Abdullah, M.N. Yusli,

Z. Zolkapli

NationalCentreforParticlePhysics,UniversitiMalaya,KualaLumpur,Malaysia

J.F. Benitez, A. Castaneda Hernandez,J.A. Murillo Quijada

UniversidaddeSonora(UNISON),Hermosillo,Mexico

H. Castilla-Valdez,E. De La Cruz-Burelo, M.C. Duran-Osuna, I. Heredia-De La Cruz34,R. Lopez-Fernandez,

J. Mejia Guisao,R.I. Rabadan-Trejo,M. Ramirez-Garcia, G. Ramirez-Sanchez, R. Reyes-Almanza,

A. Sanchez-Hernandez

S. Carrillo Moreno, C. Oropeza Barrera, F. Vazquez Valencia

UniversidadIberoamericana,MexicoCity,Mexico

J. Eysermans, I. Pedraza, H.A. Salazar Ibarguen, C. Uribe Estrada

BenemeritaUniversidadAutonomadePuebla,Puebla,Mexico

A. Morelos Pineda

UniversidadAutónomadeSanLuisPotosí,SanLuisPotosí,Mexico

D. Krofcheck

UniversityofAuckland,Auckland,NewZealand

S. Bheesette,P.H. Butler

UniversityofCanterbury,Christchurch,NewZealand

A. Ahmad, M. Ahmad, M.I. Asghar,Q. Hassan, H.R. Hoorani, A. Saddique,M.A. Shah, M. Shoaib,M. Waqas

NationalCentreforPhysics,Quaid-I-AzamUniversity,Islamabad,Pakistan

H. Bialkowska, M. Bluj,B. Boimska, T. Frueboes,M. Górski, M. Kazana, M. Szleper, P. Traczyk,P. Zalewski

NationalCentreforNuclearResearch,Swierk,Poland

K. Bunkowski,A. Byszuk35, K. Doroba,A. Kalinowski, M. Konecki,J. Krolikowski, M. Misiura,

M. Olszewski, A. Pyskir,M. Walczak

InstituteofExperimentalPhysics,FacultyofPhysics,UniversityofWarsaw,Warsaw,Poland

M. Araujo, P. Bargassa,C. Beirão Da Cruz E Silva, A. Di Francesco, P. Faccioli, B. Galinhas,M. Gallinaro, J. Hollar, N. Leonardo,M.V. Nemallapudi, J. Seixas,G. Strong,O. Toldaiev, D. Vadruccio, J. Varela

LaboratóriodeInstrumentaçãoeFísicaExperimentaldePartículas,Lisboa,Portugal

S. Afanasiev,P. Bunin, M. Gavrilenko, I. Golutvin, I. Gorbunov, A. Kamenev,V. Karjavine, A. Lanev,

A. Malakhov,V. Matveev36,37,P. Moisenz, V. Palichik,V. Perelygin, S. Shmatov, S. Shulha, N. Skatchkov,

V. Smirnov, N. Voytishin, A. Zarubin

JointInstituteforNuclearResearch,Dubna,Russia

V. Golovtsov, Y. Ivanov, V. Kim38,E. Kuznetsova39, P. Levchenko,V. Murzin, V. Oreshkin,I. Smirnov,

D. Sosnov,V. Sulimov, L. Uvarov, S. Vavilov, A. Vorobyev

PetersburgNuclearPhysicsInstitute,Gatchina(St.Petersburg),Russia

Yu. Andreev,A. Dermenev, S. Gninenko, N. Golubev, A. Karneyeu,M. Kirsanov, N. Krasnikov,

A. Pashenkov,D. Tlisov, A. Toropin

InstituteforNuclearResearch,Moscow,Russia

V. Epshteyn, V. Gavrilov, N. Lychkovskaya,V. Popov, I. Pozdnyakov, G. Safronov, A. Spiridonov,

A. Stepennov, V. Stolin, M. Toms,E. Vlasov, A. Zhokin

InstituteforTheoreticalandExperimentalPhysics,Moscow,Russia

T. Aushev

MoscowInstituteofPhysicsandTechnology,Moscow,Russia

R. Chistov40,M. Danilov40,P. Parygin, D. Philippov,S. Polikarpov40,E. Tarkovskii

V. Andreev,M. Azarkin, I. Dremin37,M. Kirakosyan, S.V. Rusakov, A. Terkulov

P.N.LebedevPhysicalInstitute,Moscow,Russia

A. Baskakov,A. Belyaev, E. Boos,A. Demiyanov,A. Ershov, A. Gribushin, O. Kodolova,V. Korotkikh,

I. Lokhtin,I. Miagkov, S. Obraztsov,S. Petrushanko, V. Savrin, A. Snigirev, I. Vardanyan

SkobeltsynInstituteofNuclearPhysics,LomonosovMoscowStateUniversity,Moscow,Russia

A. Barnyakov41, V. Blinov41, T. Dimova41,L. Kardapoltsev41, Y. Skovpen41

NovosibirskStateUniversity(NSU),Novosibirsk,Russia

I. Azhgirey,I. Bayshev,S. Bitioukov, D. Elumakhov, A. Godizov, V. Kachanov, A. Kalinin, D. Konstantinov,

P. Mandrik,V. Petrov, R. Ryutin, S. Slabospitskii, A. Sobol, S. Troshin, N. Tyurin, A. Uzunian,A. Volkov

InstituteforHighEnergyPhysicsofNationalResearchCentre‘KurchatovInstitute’,Protvino,Russia

A. Babaev,S. Baidali, V. Okhotnikov

NationalResearchTomskPolytechnicUniversity,Tomsk,Russia

P. Adzic42,P. Cirkovic, D. Devetak,M. Dordevic, J. Milosevic

UniversityofBelgrade,FacultyofPhysicsandVincaInstituteofNuclearSciences,Belgrade,Serbia

J. Alcaraz Maestre,A. Álvarez Fernández, I. Bachiller,M. Barrio Luna, J.A. Brochero Cifuentes,M. Cerrada,

N. Colino, B. De La Cruz,A. Delgado Peris,C. Fernandez Bedoya, J.P. Fernández Ramos, J. Flix, M.C. Fouz,

O. Gonzalez Lopez,S. Goy Lopez, J.M. Hernandez, M.I. Josa, D. Moran, A. Pérez-Calero Yzquierdo,

J. Puerta Pelayo, I. Redondo,L. Romero, M.S. Soares,A. Triossi

CentrodeInvestigacionesEnergéticasMedioambientalesyTecnológicas(CIEMAT),Madrid,Spain

C. Albajar, J.F. de Trocóniz

UniversidadAutónomadeMadrid,Madrid,Spain

J. Cuevas,C. Erice, J. Fernandez Menendez, S. Folgueras,I. Gonzalez Caballero, J.R. González Fernández,

E. Palencia Cortezon,V. Rodríguez Bouza, S. Sanchez Cruz, P. Vischia,J.M. Vizan Garcia

UniversidaddeOviedo,Oviedo,Spain

I.J. Cabrillo, A. Calderon, B. Chazin Quero,J. Duarte Campderros, M. Fernandez,P.J. Fernández Manteca,

A. García Alonso,J. Garcia-Ferrero,G. Gomez, A. Lopez Virto, J. Marco, C. Martinez Rivero,

P. Martinez Ruiz del Arbol,F. Matorras, J. Piedra Gomez, C. Prieels, T. Rodrigo, A. Ruiz-Jimeno,

L. Scodellaro,N. Trevisani, I. Vila, R. Vilar Cortabitarte

InstitutodeFísicadeCantabria(IFCA),CSIC-UniversidaddeCantabria,Santander,Spain

N. Wickramage

UniversityofRuhuna,DepartmentofPhysics,Matara,SriLanka

D. Abbaneo, B. Akgun,E. Auffray, G. Auzinger, P. Baillon, A.H. Ball, D. Barney, J. Bendavid,M. Bianco,

A. Bocci, C. Botta,E. Brondolin, T. Camporesi, M. Cepeda, G. Cerminara, E. Chapon, Y. Chen, G. Cucciati,

D. d’Enterria, A. Dabrowski,N. Daci, V. Daponte, A. David,A. De Roeck, N. Deelen, M. Dobson,

M. Dünser,N. Dupont,A. Elliott-Peisert, P. Everaerts,F. Fallavollita43,D. Fasanella, G. Franzoni, J. Fulcher,

W. Funk, D. Gigi,A. Gilbert, K. Gill,F. Glege, M. Guilbaud, D. Gulhan, J. Hegeman, C. Heidegger,

V. Innocente, A. Jafari,P. Janot, O. Karacheban20,J. Kieseler, A. Kornmayer, M. Krammer1, C. Lange, P. Lecoq,C. Lourenço,L. Malgeri, M. Mannelli,F. Meijers, J.A. Merlin,S. Mersi, E. Meschi, P. Milenovic44, F. Moortgat,M. Mulders, J. Ngadiuba, S. Nourbakhsh,S. Orfanelli, L. Orsini,F. Pantaleo17, L. Pape, E. Perez,M. Peruzzi, A. Petrilli, G. Petrucciani,A. Pfeiffer,M. Pierini, F.M. Pitters,D. Rabady, A. Racz,