Observation of prompt J/psi meson elliptic flow in high-multiplicity pPb collisions at √s(NN)=8.16 TeV

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Physics

Letters

B

www.elsevier.com/locate/physletb

Observation

of

prompt

J/

ψ

meson

elliptic

flow

in

high-multiplicity

pPb

collisions

at

√

s

=

8.16 TeV

Receivedinrevisedform14February2019 Accepted14February2019

Availableonline19February2019 Editor:M.Doser Keywords: CMS Heavy-ionphysics Correlation Flow pPb Heavyflavor

A measurement of the elliptic flow (v2) of prompt J/ψ mesons in high-multiplicity pPb collisions

is reported using data collectedby the CMS experiment atanucleon-nucleon center-of-mass energy

√_s

NN=8.16TeV.PromptJ/ψ mesonsdecayingintotwomuonsarereconstructedintherapidityregion

in thenucleon-nucleon center-of-mass frame( ycm), corresponding toeither−2.86<ycm<−1.86 or

0.94<ycm<1.94.Theaveragev2resultfromthetwo rapidityrangesisreportedoverthe transverse

momentum(pT)rangefrom0.2to10 GeV.Positivev2valuesare observedforthepromptJ/ψ meson,

as extracted from long-rangetwo-particle correlationswith chargedhadrons,for 2<pT<8 GeV.The

prompt J/ψ results are compared with previousCMS measurements of elliptic flow for open charm mesons (D0_{) and strange hadrons. From these measurements, constraints can be obtained on the}

collectivedynamicsofcharmquarksproducedinhigh-multiplicityeventsarisingfromsmallsystems.

©2019TheAuthor(s).PublishedbyElsevierB.V.ThisisanopenaccessarticleundertheCCBYlicense (http://creativecommons.org/licenses/by/4.0/).FundedbySCOAP3.

1. Introduction

Strongcollectivebehaviorisfoundintheazimuthalcorrelations ofparticles emitted in relativisticnucleus-nucleus (AA) collisions attheBNLRHIC[1–4] andattheCERNLHC [5–10].These correla-tions,whicharelong-rangeinpseudorapidity(η),suggestthe for-mationofastronglyinteractingquark-gluonplasma(QGP)that ex-hibitsnearlyidealhydrodynamicbehavior [11–13].Theazimuthal correlationstructureofemittedparticlesistypicallycharacterized by its Fourier components [14]. In particular, within a hydrody-namicpicture,thesecondandthirdFourieranisotropycomponents are known aselliptic (v2) andtriangular (v3) flow, respectively, andreflect the QGP medium response to the initial collision ge-ometryanditsfluctuations [15–17].Inrecentyears,similar long-rangecollectiveazimuthalcorrelationshavealsobeenobservedin eventswithhighfinal-state particlemultiplicity in proton-proton (pp) [18–21], proton-nucleus (pA) [22–30], and lighter AA colli-sions [31–33], raisingthe questionofwhethera fluid-likeQGPis createdinthesemuchsmallersystems.Whileexperimental mea-surementsinthesesmallsystemsareconsistentwiththe hydrody-namicexpansionofatinyQGPdroplet,alternativescenariosbased on gluon saturation in the initial state also claim to capturethe

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

mainfeaturesofthecorrelationdata(recentreviewsareprovided inRefs. [34,35]).

Because oftheir large masses, heavy quarks (charm and bot-tom)areprimarilyproducedviahard-scatteringprocessesatavery early stageofthecollision.Thus, theyare largelydecoupledfrom the bulk production of soft gluons and light-flavor quarks at a later stageinAA collisions, andtherebyprobethepropertiesand dynamicsoftheQGPthroughitsentireevolution [36].Astrong el-lipticflow(v2) signalhasbeenobservedforopenheavy-flavorD0 mesonsinbothAuAu collisionsatRHIC [37] andPbPb collisionsat theLHC [38–40],suggestingthatcharmquarksmaydevelopstrong collectiveflowbehavior.Furthermore,arecentmeasurementofthe ellipticflowofJ/ψ mesonsinPbPbcollisions at√sNN =5.02TeV [41] hasprovidedadditionalevidenceforthecollectivebehaviorof charmquarksintheQGP.

In the studyof collectivityin smallsystems, such asthat oc-curring in pp or pPb collisions, a key open question is whether the strong collective behavior observed for bulk constituents in high-multiplicityeventsalsoextendstocharmandbottomquarks. Long-range correlations involving inclusivemuons at high trans-verse momentum (pT) reveal a hintofheavy-flavor quark collec-tivity in pPb collisions [42]. Furthermore,the recent observation of a significant ellipticflow signal forprompt D0 mesonsin pPb collisions hasprovided evidenceforcharm quarkcollectivityin a small system [43]. The v2 signal for D0 mesons is found to be smaller thanthat oflight-flavor mesons ata given pT, indicating

https://doi.org/10.1016/j.physletb.2019.02.018

0370-2693/©2019TheAuthor(s).PublishedbyElsevierB.V.ThisisanopenaccessarticleundertheCCBYlicense(http://creativecommons.org/licenses/by/4.0/).Fundedby SCOAP3_.

thatinthesesmallsystemsthereisaweakercollectivemotionfor charmquarks,ascomparedtothatofthebulkmedium.However, astheD0 _{mesoncarriesbothalightandacharmquark, the} rela-tivecontributionofthesedifferentflavorquarkstotheobservedv2 signalisnotfullyconstrained.Withoutdetailedtheoretical model-ing,a scenario isnot excluded where the D0 meson v2 signal is entirelycarriedbythelight-flavorquark.Theobservationofan el-lipticflowsignal forJ/ψ mesonsina smallsystemcould provide moredirectevidenceofcharmquarkcollectivityandcouldimpose newconstraintsonthecollectivedynamicsofheavy-quark produc-tioninsuch collisions. Furthermore,heavy-quarkcollectivitymay alsoprovide a hintof how, in small systems, hard probes inter-actwiththeQGP [36],assumingthisisformed.Firstmeasurement ofinclusive J/ψ (combined charmonia andJ/ψ mesons from de-cayofopenbeautyhadrons) v2 inpPb collisionswasreportedin Ref. [44], wherepositive v2 coefficientswere found in therange of 3<pT<6GeV with center-of-massrapidities −4.46<ycm< −2.96 or 2.03<ycm<3.53.ArecentmodelcalculationofJ/ψ v2 in pPb collisions suggests little v2 signal arising fromfinal-state interactionsbetweencharmquarksandtheQGPmedium [45].

ThisLetterpresentsthefirst measurementofprompt J/ψ me-son elliptic flow (excluding contributions from b hadron decays) fromlong-rangetwo-particlecorrelationsinveryhighmultiplicity pPb collisionsat√sNN =8.16TeV.The v2 harmonicsforprompt J/ψ mesonsintheranges−2.86<ycm<−1.86 and0.94<ycm< 1.94 aredeterminedover awide pT rangefrom0.2to10 GeV.To estimatethepossible residualcontributionfromback-to-back jet-likecorrelations,thev2 valuesarealsopresentedaftersubtracting correlationsobtainedfromlow-multiplicitypPb events(denotedas vsub₂ ),wherejet-likecorrelationsareassumedtodominate.The re-sultsare comparedto those ofthelight strange-flavor K0

S and 

hadrons,andtheopenheavy-flavorpromptD0meson,whichwere previously reported by CMS [43] in the same pT rangebut in a differentrapidityrangeof−1.46<ycm<0.54.Inordertoexplore possiblecollectivityatthepartoniclevel,acomparisonisalso pre-sentedin terms of the transverse kinetic energy per constituent quark(K ET/nq,whereK ET=

 m2_+p2

T−m,andnqisthenumber ofconstituentquarks).

2. TheCMSdetector

The central feature of the CMS apparatus is a superconduct-ing solenoidof 6 m internal diameter,providing a magnetic field of3.8 T.Withinthesolenoidvolume,there arefourprimary sub-detectorsincludingasiliconpixelandstriptrackerdetector,alead tungstatecrystalelectromagneticcalorimeter,andabrassand scin-tillator hadron calorimeter, each composed of a barrel and two endcapsections.Iron andquartz-fiberCherenkovhadron forward (HF)calorimeterscovertherange3.0<|η|<5.2.Muonsare mea-suredintherange|η|<2.4 ingas-ionizationdetectorsembedded inthesteel flux-returnyoke outsidethesolenoid, withdetection planes made using three technologies: drift tubes, cathode strip chambers, and resistive-plate chambers. The silicon tracker mea-sures charged particles within the range |η|<2.5. For charged particleswith1<pT<10GeV and|η|<1.4,thetrackresolutions aretypically1.5%in pT and25–90(45–150)μminthetransverse (longitudinal)impactparameter [46].Adetaileddescriptionofthe CMS detector, together with a definition of the coordinate sys-tem used and the relevant kinematic variables, can be found in Ref. [47].

3. DataselectionandJ/ψmesonreconstruction

The pPb data at√sNN =8.16TeV used in thisanalysis were collected in 2016, and correspond to an integrated luminosity

of 186 nb−1. The beamenergies are 6.5 TeV for the protons and 2.56 TeV per nucleon for the lead nuclei. Because of the asym-metricbeamconditions,particlesselectedinthelaboratory rapid-ity rangeof 1.4< ylab<2.4 (−2.4<ylab<−1.4) have a corre-spondingnucleon-nucleon center-of-massframe rapidityrange of 0.94< ycm<1.94 (−2.86< ycm<−1.86), with positive rapid-ity definedin the proton beamdirection. Tominimize statistical uncertainties,the quotedJ/ψ meson v2 resultscombinethe indi-vidualvaluesobtainedfortheprotonandleadbeamdirections.

ThepPb dataareanalyzedindifferentrangesofNoffline trk ,where Noffline_trk isthenumberofprimarychargedparticletracks [46] with |η|<2.4 and pT>0.4GeV. The main results are obtained with eventsinthehigh-multiplicityrange185≤Noffline

trk <250.Toselect these events, dedicated triggers were developed, as discussed in Refs. [48,49]. Events with N_trkoffline<35 are also used to estimate the possible contribution of residual back-to-back jet-like corre-lations. These lower-multiplicity events are selected online with a hardware-based trigger requiring two muon candidates in the muon detectors with no explicit momentum or rapidity thresh-old [50].Intheofflineanalysis,hadroniccollisionsareselectedby requiringatleastoneHFcalorimetertowerwithmorethan3 GeV oftotalenergyineachofthetwoHFdetectors.Eventsmust con-tainaprimaryvertexclosetothenominalinteractionpointofthe beams,within 15 cm alongthe beamdirection, and0.2 cm inthe plane transverse to beam direction. The Noffline_trk range limits cor-respondto fractional inelasticcrosssectionsfrom100 to57% for Noffline_trk <35,andfrom0.33 to0.01% for185≤N_trkoffline<250, re-spectively.

Theofflinemuonreconstructionalgorithmstartseitherby find-ing tracks in the muon detectors, whichare then fittedtogether withtracks reconstructedin thesilicontracker (globalmuons),or by extrapolatingtracksfromthesilicontrackertomatchahiton at leastone segment of themuon detectors (trackermuons).The muon candidates are required to pass the identification criteria of theparticle-flow algorithm [51], which suppresses contamina-tionof“punch-through”hadronsmisidentifiedasmuons,basedon energydepositioninthecalorimeters.Thesoft muonselection cri-teria arealsoimposed,asdefinedinRef. [52], tofurtherimprove thepurityofmuons.

The J/ψ meson candidates are formed from pairs of oppo-sitely charged muons, originating from a common vertex. Based on the vertexprobability distributions forsignal and background candidates,theprobabilitythatthedimuonpairsharesacommon vertexis requiredto be larger than1%, loweringthe background from random combinations as well asfrom semileptonic decays of bottom and charm hadrons. Because of the long lifetime of b hadrons compared to that of J/ψ mesons, the nonprompt J/ψ

meson componentcan be reducedby placing constraints on the pseudo-properdecaylength [53].Thisisdefinedby

3D_J/ψ=Lxyz

mJ/ψ |pμμ|,

(1)

where Lxyz isthedistancebetweenthe primaryanddimuon ver-tices,mJ/ψ istheParticle Data Group[54] worldaveragevalue of theJ/ψ mesonmass(assumedforalldimuoncandidates),andpμμ isthedimuonmomentum.Theupperlimit (decreasingasa func-tion of pT) imposed on the 3DJ/ψ value is based on Monte Carlo (MC)studieswithsimulatedeventsamplesof pythia 8.209 [55,56], andfound to reject75–90% (fromlow to high pT) of nonprompt J/ψ mesons,largelyindependentofmultiplicity.Theresidual non-promptJ/ψ mesonfractioninthedataisestimatedtobe approx-imately5% acrossthefull pT range,anditseffectonthe v2 mea-surementis propagated asa systematicuncertainty, asdescribed inSection5.

Fig. 1. Example of fits to the invariant mass spectrum (left) and the v2S+B(minv)distribution (right) in the pTinterval 6.0–8.0 GeV for pPb events with 185≤Ntrkoffline<250.

4. Analysistechnique

Theazimuthal anisotropy ofJ/ψ mesonsis extractedfromthe long-range(|η|>1) two-particleazimuthal correlations, follow-ing an identical procedure to that described in Refs. [21,27,43]. A two-dimensional(2D)correlationfunctionisconstructedby pair-ing each J/ψ candidate with reference primary charged-particle trackswith0.3<pT<3 GeV and|η|<2.4 (denotedas“ref” parti-cles),andcalculating

1 NJ/ψ d2Npair dηdφ =B(0,0) S(η,φ) B(η,φ), (2)

whereηandφ are thedifferencesin η andintheazimuthal angle(φ)ofthepair.Thesame-eventpairdistribution,S(η,φ), representstheyieldofparticlepairsnormalizedbythenumberof J/ψ candidatesfrom the sameevent. The mixed-eventpair yield distribution, B(η,φ),is constructedby pairing J/ψ candidates in each eventwiththe reference primary charged-particle tracks from20differentrandomlyselectedevents,fromthesameN_trkoffline rangeandhavingaprimary vertexfallinginthe same2 cm wide rangeofreconstructedlongitudinal,z coordinate.Theanalysis pro-cedureisperformedineach pT andinvariantmass(minv)rangeof J/ψ candidates.A correction for the acceptance andefficiency of theJ/ψ mesonyieldsisapplied,butfoundtohaveanegligible ef-fectonthemeasurements.Theφ correlation functionsaveraged over|η|>1 (toremoveshort-rangecorrelations,suchasjet frag-mentation)arethenobtainedfromthe2Ddistributionsandfitted by the first three terms of a Fourierseries (including additional termshasanegligibleeffectonthefitresults):

1 NJ/ψ dNpair dφ = Nassoc 2π  1+ 3  n=1 2Vncos(nφ)  . (3)

Here, Vn are the Fourier coefficients and Nassoc represents the total number of same-event pairs per J/ψ candidate for a given invariant mass interval. By assuming that Vn is the prod-uct of single-particle anisotropies of J/ψ mesons and reference charged particles [57], Vn(J/ψ,ref)=vn(J/ψ)×vn(ref), the vn anisotropy harmonics for J/ψ candidates can be extracted as a functionofinvariantmass, vn(J/ψ)=Vn(J/ψ,ref)/

√

Vn(ref,ref). The Vn(ref,ref) represents the Fouriercoefficients extracted by correlatingtworeferencechargedparticles.Withthecurrentdata, onlythesecondorder(n=2) ellipticanisotropyharmoniccanbe measuredwithmeaningfulstatisticalprecision.

Toextractthegenuine v2 valuesoftheJ/ψ mesonsignal (v₂S), the contributionfrombackgroundcandidates(v₂B) hastobe sub-tractedfromthev2valuesofallJ/ψ mesoncandidates,asobtained inthepreviousstep.Theprocedureistofirstfitthedimuonmass spectrum with a function composed of three components: two CrystalBallfunctions [58] withdifferentwidthsbutcommonmean andtailparametersfortheJ/ψ signal(thetailparametersarefixed tothevaluesobtainedfromsimulation), S(minv),andan exponen-tial function to model the background, B(minv). Then, the signal plusbackgroundv₂S+B(minv)distributionisfittedwith:

vS₂+B(minv)=α(minv)v2S+ [1−α(minv)]vB2(minv), (4) where

α(minv)=

S(minv)

S(minv)+B(minv)

. (5)

Here, v₂B(minv) for the background J/ψ candidates is modeled as an exponentialfunction oftheinvariant mass,and α(minv) isthe J/ψ signalfractionobtainedfromthemassspectrumfit.An exam-pleoffitstothemassspectrumandv₂S+B(minv)inthe pT interval 6.0–8.0 GeV forthemultiplicityrange185≤Noffline

trk <250 isshown in Fig. 1. The residual contribution of back-to-back dijets to the measured v2resultsisestimatedfromlow-multiplicitypPb events andis removed fromthesignal afteraccountingfor thejet yield ratioofthe selectedevents,followingajet subtractionprocedure similar to that established inRefs. [21,43,57]. The Fourier coeffi-cients, Vn,extractedfromEq. (3) forNoffline_trk <35,aresubtracted fromthe Vncoefficientsobtainedinthehigh-multiplicityregion, with V_nsub_ =Vn−Vn(Nofflinetrk <35) ×Nassoc(N offline trk <35) Nassoc × Yjet Yjet(Nofflinetrk <35) . (6)

Here, Yjet represents the jet yield obtained by integrating the difference of the short-range (|η|<1) and long-range event-normalizedassociatedyields foreachmultiplicity class.Theratio, Yjet/Yjet(Noffline_trk <35),is introduced to account for theenhanced jet correlationsresulting fromtheselection ofhigher-multiplicity events.ForpT(J/ψ)<4.5GeV,thejetyieldratiocannotbedirectly estimatedfromthetwo-particleazimuthalcorrelations,astheJ/ψ

chargedparticles.Therefore,thevalue isassumedtobethesame asthatforthehigh-pTregion,wherenopTdependencehasbeen observed. It was also previously observed that the values of jet yieldratio forD0 _{and strange particlespecies show little} depen-denceonpT overthefull pTrange [43].

5. Systematicuncertainties

Sources of systematic uncertainties on the prompt J/ψ me-son v2 measurementincludethe J/ψ mesonyieldcorrection (ac-ceptance and efficiency correction derived from pythia simula-tion), the nonprompt J/ψ meson contamination, the background vB

2(minv) functional form, the signal and background invariant mass PDF, the jet subtraction procedure, the contamination of eventscontainingmorethanonepPb interaction(pileup),andthe triggerbias.In thisLetter,the quoted uncertainties in v2 are ab-solutevalues,andarefoundtohavenodependenceon pT,except those for the jet subtraction procedure. Systematic uncertainties originatingfromdifferentsources are addedinquadratureto ob-taintheoverallsystematicuncertaintyshownasboxesinthe fig-ures.

To evaluate the uncertainties arising from the efficiency cor-rection to the J/ψ meson yield, the v2 values are compared to the uncorrected ones, yielding an uncertainty of 0.008. The ef-fect on the measured v2 due to the residual contribution from nonprompt J/ψ mesons is evaluated by varying the 3D_J/ψ require-ment such that the nonprompt J/ψ meson yield is doubled. The v2 values are found not to change by more than ±0.004,which is assigned asthe systematicuncertainty dueto the J/ψ meson yieldcorrection. Possible differencesinthe rejectionefficiencyof nonpromptJ/ψ mesonsbetweendataandsimulation are investi-gatedandfoundtobenegligible.Thesystematicuncertaintiesfrom the background v2 functional form are evaluated by comparing v₂B(minv) values basedon first-,second-, and third-order polyno-mial fits to the backgrounddistribution. The resulting J/ψ signal v2 valuesare foundtovarybylessthan0.009.Systematiceffects relatedtosignal invariantmassPDFarefoundto benegligibleby releasing,one ata time, the fixed tail parameters of the Crystal Ballfunctions.Thevariationofv2,whilechangingthebackground invariant massPDF to a second- orthird-order polynomial func-tionisalsofoundtobenegligible.Inthejetsubtractionprocedure, thestatistical precision of the jet yield ratio islimited. The vsub₂ resultsare found to be consistent within ±0.002 to±0.014 (in-creasingwithpT)whenvaryingthejetyieldratiobyitsstatistical uncertainty.Thesystematicuncertaintiesfromthepotentialpileup effectandthetriggerbiasaretakentobethesameasforinclusive chargedparticlesinRef. [49],wheretheycanbeestablishedwith goodstatisticalprecision.Thepileupandtriggerbiasuncertainties arenegligiblecomparedtotheother sourcesofsystematic uncer-tainties,asthe fractionof residualpileup eventsis only a few% andthetriggerefficiencyiscloseto100%.

6. Results

Fig. 2 shows the v2 results of prompt J/ψ mesons at for-wardrapidities (−2.86<ycm<−1.86 or0.94<ycm<1.94) for high-multiplicity (185≤Noffline_trk <250) pPb collisions, covering a pT range from0.2 to10 GeV. Results obtained separately forJ/ψ meson rapidity in the Pb- and p-going direction are compared, andfound to be consistent within statistical uncertainties. Thus, as mentioned earlier, combined v2 values are presented for the best statistical precision. The v2 results for K0S and  hadrons (light,strange-flavor),andpromptD0 _{mesons(openheavy-flavor),} reported in a previous CMS publication [43] for the midrapidity region−1.46<ycm<0.54,arealsoshownforcomparison.

Fig. 2. The v2 results ofthe promptJ/ψ mesonsat forwardrapidities(−2.86<

ycm<−1.86 or0.94<ycm<1.94),asafunctionofpTinthemultiplicityrange 185≤Noffline

trk <250 for pPb collisions at

√_s

NN =8.16TeV. Datafor K0S and  hadrons,andpromptD0_{mesonsatmidrapidity(−1.46<y}

cm<0.54)fromprevious CMSmeasurements [43] arealsoshownforcomparison.Theerrorbarscorrespond tostatisticaluncertainties,whiletheshadedareasdenotethesystematic uncertain-ties.

PositivepromptJ/ψ mesonv2valuesareobservedoverawide pT range from about 2 to 8 GeV. The prompt J/ψ meson v2 re-sults show atrend offirst increasing up to pT∼4 GeV andthen decreasingtowardhigherpT.Thisobservedtrendappearstobein common with the other hadron species shown. In the pT range below 5 GeV, the v2 values for J/ψ and D0 mesons are consis-tentwitheachotherwithin theuncertainties,whileanindication of smaller v2 values for J/ψ mesons than that for D0 mesons is seen for pT>5 GeV, although the difference is not significant within currentexperimental uncertainties.Overthefull pT range, thev2 signalvaluesforbothJ/ψ andD0 hadronsaresmallerthan those for K0

S and hadrons. This observation is consistent with the earlier conclusion that charm quarks develop a weaker col-lectivedynamicsthanlight quarksinsmallsystems [43]. Because of experimental limitation, v2 values for the prompt J/ψ meson andthe other mesonspecies are not compared within the same rapidity range, possibly affecting their comparison. The rapidity dependence of v2 values for charged particles in pPb collisions hasbeenmeasured [59,60],suggestinguptoaround15%variation from|ylab|∼0 to2.4.

Tobetterstudytheellipticflowsignalcomingpurelyfrom long-range collective correlations, the J/ψ v2 results are corrected for residualjet correlations. The resulting(vsub

2 ) valuesare shownin Fig. 3 (upper) for prompt J/ψ mesons as a function of pT with 185≤Noffline

trk <250, andcompared to similarly corrected K 0 S, , andD0_{hadronresults [43].Theeffectofthecorrectionforall} par-ticlespeciesismostnoticeableatveryhigh pT,whiletheoverall pT dependenceofthev2 dataremainsunchanged.TheK0S mesons have a larger correction applied to their v2 values (possibly be-cause K0_S mesonsare morecorrelated with the bulk multiplicity, and thus are biased toward stronger jet correlations due to the selection of high multiplicities) and their vsub₂ values after the correction tend to converge to those of the prompt J/ψ and D0 mesonsathighpT.

ArecentmodelcalculationofJ/ψ v2 inminimumbiaspPb col-lisions,based onfinal-stateinteractionsbetweenproducedcharm quarksandaQGPmedium,suggestsaverysmallv2 signalofless than0.01 [45].Thiscalculationindicates thatadditional contribu-tions, e.g.,those frominitial-stateinteractions, maybe neededto accountfortheobservedv2 signalofpromptJ/ψ mesonsfor high-multiplicitypPb eventsreportedinthisLetter.

Motivated by the possible formation of a hydrodynamically expanding QGP medium in small systems, the elliptic flow sig-nals for K0

Fig. 3. Upper:thevsub

2 valuesforpromptJ/ψmesonsatforwardrapidities(−2.86<

ycm<−1.86 or0.94<ycm<1.94),aswellasforK0Sandhadrons,andprompt D0_{mesonsatmidrapidity(−1}

.46<ycm<0.54),asafunctionofpTforpPb colli-sionsat√sNN =8.16TeV with185≤Ntrkoffline<250.Lower:thenq-normalizedvsub2 results.TheK0

S,andD 0 _vsub

2 dataaretakenfromRef. [43].Theerrorbars cor-respondtostatisticaluncertainties,whiletheshadedareasdenotethesystematic uncertainties.

of transverse kinetic energy (K ET) in Fig. 3 (lower), to account for the mass difference among the four hadron species [61,62]. Here, the valuesof vsub₂ and K ET are both divided by the num-berofconstituentquarks,nq,torepresentthecollectiveflow sig-nal atthe partoniclevel in the context ofthe quark coalescence model [63–65],which postulates thatthe ellipticflowsignal ofa hadronisasumofcontributionsfromindividualconstituentquark flow values.Aswas previously reportedin pPb collisions [27,43], ascalingofnq-normalizedv2subvaluesisobservedbetweentheK0S mesonandbaryon,showninFig.3(lower).Thisscalingbetween lightbaryon andmesonspeciessystemsproducedinthecollision (known as the number-of-constituent-quarkor NCQ scaling) was firstdiscoveredinAA collidingsystems [61,62,66],indicatingthat collectivityis first developed amongthe partons,which later re-combineintofinal-statehadrons.Theellipticflowsignalperquark (vsub₂ /nq) forprompt J/ψ mesonsatlow K ET/nq rangeis consis-tent with those of K0

S, , and prompt D0 hadrons within large statisticaluncertainties forthe current data.There isa hintthat thepromptJ/ψ mesondatatendtofallonthesametrendasthose ofK0

S and baryons,allofwhich areabove theprompt D0 me-sondata.However, thedifferencebetweenthepresentpromptD0 andJ/ψ mesonresultsdeviatesfrom0withasignificanceofonly about1.2standarddeviationsatK ET/nq≈0.4 GeV.Amore defini-tiveconclusioncouldbedrawnwithfuturehighprecisiondata.For K ET/nq>1GeV,the vsub₂ /nq forprompt D0 andJ/ψ mesons are consistentlybelowthatoftheK0_S meson.Anindication ofsmaller vsub₂ /nq values for J/ψ mesons than for D0 mesons is seen for K ET/nq>1GeV.AsJ/ψ mesonscontaintwocharm quarks,while

D0 _{mesons contain a charm and a light-flavor quark, this} obser-vation would be consistent with a weaker collective behavior of heavy-flavor quarks than light quarks, possibly a consequence of the much smaller size of the collision system. Future data with improved precisionwill providecrucialinsights tofully constrain the collective behavior oflight- and heavy-flavor quarks in high-multiplicity,smallsystems.

7. Summary

In summary, the elliptic flow harmonic (v2) for prompt J/ψ mesonsinhigh-multiplicityproton-lead(pPb)collisionsat√sNN = 8.16TeV ispresentedasafunctionoftransversemomentum(pT). Positivev2valuesareobservedforpromptJ/ψ mesonsatforward rapidity(−2.86<ycm<−1.86 or0.94<ycm<1.94)overawide pT range(2<pT<8 GeV). Thisobservationprovidesevidencefor charm quark collectivityin high-multiplicity pPb collisions, sim-ilar to that first observed for light-flavor hadrons. The observed ordering of v2 among light-flavor, open and hiddenheavy-flavor hadrons at intermediate and high-pT regions (e.g., above 4 GeV) adds support to the earlier conclusion that heavy quarks exhibit weakercollectivebehaviorthanlightquarksorgluonsinsmall sys-tems.Forparticle transversekinetic energyperconstituentquark valueslessthan1 GeV,the v2ofpromptJ/ψ mesonsisconsistent withpromptD0,K0_Sandhadrons,withincurrentuncertainties.A modelcalculationbasedonfinal-stateinteractionsbetweencharm quarksandaQGPmediuminpPb collisionssignificantly underes-timates themeasuredpromptJ/ψ v2 signal.ThenewpromptJ/ψ meson results,together with previous results forlight-flavor and openheavy-flavorhadrons,providenovelinsightsintothe dynam-ics of the heavy quarks produced in small systems that lead to highfinal-statemultiplicities.

Acknowledgements

WecongratulateourcolleaguesintheCERNaccelerator depart-ments for the excellent performance of the LHC and thank the technical andadministrativestaffs atCERNand atother CMS in-stitutes for their contributions to the success of the CMS effort. Inaddition,wegratefullyacknowledgethecomputingcentresand personneloftheWorldwideLHCComputingGridfordeliveringso effectively thecomputinginfrastructure essentialto our analyses. Finally, we acknowledge the enduring support for the construc-tion andoperationofthe LHCandtheCMSdetectorprovided by the followingfundingagencies: BMBWFandFWF(Austria);FNRS and FWO (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); MSIP andNRF (Republicof Korea);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); NASU andSFFR (Ukraine); STFC (United Kingdom);DOEand NSF (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);theLeventis Foun-dation; the A.P. Sloan Foundation; the Alexander von 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 projectno.30820817;theMinistryofEducation,YouthandSports (MEYS) of the Czech Republic; the Lendület (“Momentum”) Pro-gramme and the János Bolyai Research Scholarship of the Hun-garian Academy of Sciences, the New National Excellence Pro-gram ÚNKP, the NKFIA research grants 123842, 123959, 124845, 124850 and 125105 (Hungary); the Council of Science and In-dustrial Research, India; the HOMING PLUS programme of the Foundation for Polish Science, cofinanced from European Union, RegionalDevelopment Fund, theMobilityPlus programmeofthe 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 Estatal de Fomento de la Investigación Científica y Técnica de ExcelenciaMaríade Maeztu,grantMDM-2015-0509 andthe Pro-grama Severo Ochoa del Principado de Asturias; the Thalis and Aristeia programmes cofinancedby EU-ESF and the Greek NSRF; theRachadapisekSompotFundforPostdoctoralFellowship, Chula-longkornUniversity andthe ChulalongkornAcademicintoIts 2nd CenturyProjectAdvancementProject (Thailand);theWelch Foun-dation,contractC-1845;andtheWestonHavensFoundation(USA). References

[1] B.Alver,etal., PHOBOS,Systemsizedependenceofclusterpropertiesfrom two- particleangularcorrelationsinCu+CuandAu+Aucollisionsat √sNN= 200 GeV,Phys.Rev.C81(2010)024904,https://doi.org/10.1103/PhysRevC.81. 024904,arXiv:0812.1172.

[2] J. Adams, et al., STAR, Distributions of charged hadrons associated with hightransversemomentumparticlesinpp andAu+Aucollisionsat√sNN = 200 GeV,Phys.Rev.Lett.95(2005)152301,https://doi.org/10.1103/PhysRevLett. 95.152301,arXiv:nucl-ex/0501016.

[3] B.I.Abelev,etal.,STAR,Longrangerapiditycorrelationsandjetproductionin highenergynuclearcollisions,Phys.Rev.C80(2009)064912,https://doi.org/ 10.1103/PhysRevC.80.064912,arXiv:0909.0191.

[4] B.Alver,etal.,PHOBOS,Hightransversemomentumtriggeredcorrelationsover alargepseudorapidityacceptanceinAu+Aucollisionsat√sNN=200 GeV,Phys. Rev.Lett.104(2010)062301,https://doi.org/10.1103/PhysRevLett.104.062301, arXiv:0903.2811.

[5] CMSCollaboration,Long-rangeandshort-rangedihadronangularcorrelations incentralPbPbcollisionsatanucleon-nucleoncenterofmassenergyof2.76 TeV,J.HighEnergyPhys.07(2011)076,https://doi.org/10.1007/JHEP07(2011) 076,arXiv:1105.2438.

[6] CMSCollaboration, Centrality dependence ofdihadron correlations and az-imuthalanisotropy harmonics inPbPbcollisions at √sNN = 2.76TeV, Eur. Phys. J. C 72 (2012) 2012, https://doi.org/10.1140/epjc/s10052-012-2012-3, arXiv:1201.3158.

[7] ALICECollaboration,EllipticflowofchargedparticlesinPb-Pbcollisionsat2.76 TeV,Phys. Rev.Lett.105(2010)252302, https://doi.org/10.1103/PhysRevLett. 105.252302,arXiv:1011.3914.

[8] ATLAS Collaboration, Measurementofthe azimuthal anisotropyfor charged particle productionin √sNN =2.76 TeV lead-leadcollisions withthe ATLAS detector,Phys.Rev.C86(2012)014907,https://doi.org/10.1103/PhysRevC.86. 014907,arXiv:1203.3087.

[9] CMSCollaboration,Measurementoftheelliptic anisotropyofcharged parti-clesproducedinPbPbcollisionsatnucleon-nucleoncenter-of-massenergy= 2.76TeV,Phys.Rev.C87(2013)014902,https://doi.org/10.1103/PhysRevC.87. 014902,arXiv:1204.1409.

[10] CMSCollaboration,Studiesofazimuthaldihadroncorrelationsinultra-central PbPbcollisionsat√sNN=2.76 TeV,J.HighEnergyPhys.02(2014)088,https://

doi.org/10.1007/JHEP02(2014)088,arXiv:1312.1845.

[11] J.-Y.Ollitrault,Anisotropyasasignatureoftransversecollectiveflow,Phys.Rev. D46(1992)229,https://doi.org/10.1103/PhysRevD.46.229.

[12] U.Heinz,R. Snellings,Collectiveflow andviscosity inrelativisticheavy-ion collisions, Annu.Rev.Nucl. Part.Sci.63(2013)123,https://doi.org/10.1146/ annurev-nucl-102212-170540,arXiv:1301.2826.

[13] C. Gale, S. Jeon, B. Schenke, Hydrodynamic modeling of heavy-ion col-lisions, Int. J. Mod. Phys. A 28 (2013) 1340011, https://doi.org/10.1142/ S0217751X13400113,arXiv:1301.5893.

[14] S.Voloshin,Y. Zhang,FlowstudyinrelativisticnuclearcollisionsbyFourier expansionofazimuthalparticledistributions,Z.Phys.C70(1996)665,https:// doi.org/10.1007/s002880050141,arXiv:hep-ph/9407282.

[15] B.H. Alver,C. Gombeaud, M. Luzum, J.-Y.Ollitrault, Triangular flow in hy-drodynamics and transporttheory, Phys. Rev.C82(2010) 034913, https:// doi.org/10.1103/PhysRevC.82.034913,arXiv:1007.5469.

[16] B. Schenke, S. Jeon, C. Gale,Elliptic and triangularflow in event-by-event D=3+1 viscoushydrodynamics, Phys. Rev.Lett. 106 (2011)042301, https:// doi.org/10.1103/PhysRevLett.106.042301,arXiv:1009.3244.

[17] Z.Qiu,C.Shen,U.Heinz,HydrodynamicellipticandtriangularflowinPb-Pb collisionsat√sNN=2.76 TeV,Phys.Lett.B707(2012)151,https://doi.org/10.

1016/j.physletb.2011.12.041,arXiv:1110.3033.

[18] CMSCollaboration,Observationoflong-rangenear-sideangularcorrelationsin proton-protoncollisionsattheLHC,J.HighEnergyPhys.09(2010)091,https:// doi.org/10.1007/JHEP09(2010)091,arXiv:1009.4122.

[19] ATLASCollaboration,Observationoflong-rangeellipticazimuthalanisotropies in √s=13 and 2.76 TeV pp collisions with the ATLAS detector, Phys. Rev.Lett.116(2016)172301,https://doi.org/10.1103/PhysRevLett.116.172301, arXiv:1509.04776.

[20] CMSCollaboration,Measurementoflong-rangenear-sidetwo-particleangular correlationsinppcollisionsat√s=13TeV,Phys.Rev.Lett.116(2016)172302,

https://doi.org/10.1103/PhysRevLett.116.172302,arXiv:1510.03068.

[21] CMSCollaboration,EvidenceforcollectivityinppcollisionsattheLHC,Phys. Lett. B765(2017)193,https://doi.org/10.1016/j.physletb.2016.12.009,arXiv: 1606.06198.

[22] CMSCollaboration,Observationoflong-rangenear-sideangularcorrelationsin proton-leadcollisionsattheLHC,Phys.Lett.B718(2013)795,https://doi.org/ 10.1016/j.physletb.2012.11.025,arXiv:1210.5482.

[23] ALICECollaboration,Long-rangeangularcorrelationsonthenearandawayside inpPb collisionsat√sNN=5.02 TeV,Phys.Lett.B719(2013)29,https://doi.

org/10.1016/j.physletb.2013.01.012,arXiv:1212.2001.

[24] ATLASCollaboration,Observationofassociatednear-sideandaway-side long-range correlations in √sNN = 5.02 TeV proton-lead collisions with the AT-LAS detector, Phys. Rev. Lett. 110 (2013) 182302, https://doi.org/10.1103/ PhysRevLett.110.182302,arXiv:1212.5198.

[25] LHCbCollaboration,Measurementsoflong-rangenear-sideangularcorrelations in√sNN=5 TeV proton-leadcollisionsintheforwardregion,Phys.Lett.B762 (2016)473,https://doi.org/10.1016/j.physletb.2016.09.064,arXiv:1512.00439. [26] ALICE Collaboration,Long-rangeangularcorrelations ofπ,Kandpinp–Pb

collisionsat√sNN=5.02 TeV,Phys.Lett.B726(2013)164,https://doi.org/10.

1016/j.physletb.2013.08.024,arXiv:1307.3237.

[27] CMS Collaboration, Long-rangetwo-particle correlations ofstrange hadrons with charged particles in pPb and PbPb collisions at LHC energies, Phys. Lett. B742(2015) 200,https://doi.org/10.1016/j.physletb.2015.01.034,arXiv: 1409.3392.

[28] CMS Collaboration, Evidence for collective multi-particle correlations in pPb collisions, Phys. Rev. Lett. 115 (2015) 012301, https://doi.org/10.1103/ PhysRevLett.115.012301,arXiv:1502.05382.

[29] ATLASCollaboration,Measurementofmulti-particleazimuthalcorrelationsin pp, p+Pb and low-multiplicity Pb+Pb collisions with the ATLAS detector, Eur.Phys.J.C77(2017)428,https://doi.org/10.1140/epjc/s10052-017-4988-1, arXiv:1705.04176.

[30] ATLASCollaboration,Measurementoflong-rangemultiparticleazimuthal cor-relationswiththesubeventcumulantmethodinpp andp+ P b collisionswith theATLASdetectorattheCERNLargeHadronCollider,Phys.Rev.C97(2018) 024904,https://doi.org/10.1103/PhysRevC.97.024904,arXiv:1708.03559. [31] L.Adamczyk,etal.,STAR,Long-rangepseudorapiditydihadroncorrelationsin

d+Aucollisionsat√sNN=200 GeV,Phys.Lett.B747(2015)265,https://doi.

org/10.1016/j.physletb.2015.05.075,arXiv:1502.07652.

[32] A.Adare,etal.,PHENIX,Measurementsofellipticandtriangularflowin high-multiplicity3_{He+Aucollisionsat}√_s

NN=200GeV,Phys.Rev.Lett.115(2015) 142301,https://doi.org/10.1103/PhysRevLett.115.142301,arXiv:1507.06273. [33] C.Aidala,etal.,PHENIX,Measurementsofmultiparticlecorrelationsind+Au

collisionsat200,62.4,39,and19.6GeVandp+Au collisionsat200GeVand implicationsforcollectivebehavior,Phys.Rev.Lett.120(2018)062302,https:// doi.org/10.1103/PhysRevLett.120.062302,arXiv:1707.06108.

[34] K. Dusling, W.Li, B. Schenke, Novel collective phenomena in high-energy proton–proton andproton–nucleuscollisions, Int.J. Mod.Phys. E25(2016) 1630002,https://doi.org/10.1142/S0218301316300022,arXiv:1509.07939. [35]J.L.Nagle,W.A.Zajc,Smallsystemcollectivityinrelativistichadronandnuclear

collisions,arXiv:1801.03477,2018.

[36] P.Braun-Munzinger, Quarkoniumproductioninultra-relativisticnuclear col-lisions:suppressionversusenhancement,J.Phys.G34(2007)S471,https:// doi.org/10.1088/0954-3899/34/8/S36,arXiv:nucl-th/0701093.

[37] L.Adamczyk,etal.,STAR,MeasurementofD0_{azimuthalanisotropyat} midra-pidityinAu+ Aucollisionsat √sNN=200GeV,Phys.Rev.Lett.118(2017) 212301,https://doi.org/10.1103/PhysRevLett.118.212301,arXiv:1701.06060. [38] ALICECollaboration,AzimuthalanisotropyofDmesonproductioninPb-Pb

col-lisionsat√sNN=2.76 TeV,Phys.Rev.C90(2014)034904,https://doi.org/10.

1103/PhysRevC.90.034904,arXiv:1405.2001.

[39] ALICECollaboration,D-mesonazimuthalanisotropyinmidcentralPb-Pb colli-sionsat√sNN=5.02 TeV,Phys.Rev.Lett.120(2018)102301,https://doi.org/

10.1103/PhysRevLett.120.102301,arXiv:1707.01005.

[40] CMSCollaboration,MeasurementofpromptD0_{mesonazimuthalanisotropyin} Pb-Pbcollisionsat√sNN=5.02 TeV,Phys.Rev.Lett.120(2018)202301,https://

doi.org/10.1103/PhysRevLett.120.202301,arXiv:1708.03497.

[41] ALICECollaboration,J/ψ ellipticflowinPb-Pbcollisionsat√sNN=5.02 TeV, Phys. Rev.Lett. 119 (2017) 242301, https://doi.org/10.1103/PhysRevLett.119. 242301,arXiv:1709.05260.

[42] ALICECollaboration, Forward-centraltwo-particle correlations inp-Pb colli-sionsat√sNN=5.02 TeV,Phys.Lett.B753(2016)126,https://doi.org/10.1016/

j.physletb.2015.12.010,arXiv:1506.08032.

[43] CMS Collaboration, Elliptic flow of charm and strange hadrons in high-multiplicitypPbcollisionsat√sNN=8.16TeV,Phys.Rev.Lett.(2018),https://

doi.org/10.3204/PUBDB-2018-02206,arXiv:1804.09767.

[44] ALICECollaboration, Search for collectivity with azimuthal J/ψ-hadron cor-relations in highmultiplicity p-Pbcollisions at √sNN = 5.02and 8.16 TeV, Phys.Lett.B780(2018)7,https://doi.org/10.1016/j.physletb.2018.02.039,arXiv: 1709.06807.

[45]X.Du,R.Rapp,In-mediumcharmoniumproductioninproton-nucleus colli-sions,arXiv:1808.10014,2018.

[46] CMSCollaboration,Descriptionandperformanceoftrackandprimary-vertex reconstructionwiththeCMStracker,J.Instrum.9(2014)P10009,https://doi. org/10.1088/1748-0221/9/10/P10009,arXiv:1405.6569.

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

[48] CMS Collaboration, Constraintson the chiral magneticeffectusing charge-dependent azimuthal correlations inpPb and PbPb collisions at the CERN LargeHadronCollider,Phys.Rev.C97(2018)044912,https://doi.org/10.1103/ PhysRevC.97.044912,arXiv:1708.01602.

[49] CMSCollaboration,Observationofcorrelatedazimuthalanisotropyfourier har-monicsinppandpPb collisionsattheLHC,Phys.Rev.Lett.120(2018)092301,

https://doi.org/10.1103/PhysRevLett.120.092301,arXiv:1709.09189.

[50] CMSCollaboration,EventactivitydependenceofY(nS)productionin√sNN= 5.02 TeV pPband√s =2.76 TeV ppcollisions,J.HighEnergyPhys.04(2014) 103,https://doi.org/10.1007/JHEP04(2014)103,arXiv:1312.6300.

[51] CMSCollaboration, Particle-flowreconstructionand globaleventdescription withtheCMSdetector,J.Instrum.12(2017)P10003,https://doi.org/10.1088/ 1748-0221/12/10/P10003,arXiv:1706.04965.

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

[53] D. Buskulic,et al.,ALEPH,Measurementofthe B0 _andB− _{mesonlifetimes,}

Phys.Lett.B307(1993)194,https://doi.org/10.1016/0370-2693(93)90211-Y, Erratum:https://doi.org/10.1016/0370-2693(94)90054-X.

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

[55] T. Sjöstrand,S.Mrenna,P.Skands,Abrief introductiontoPYTHIA8.1, Com-put.Phys.Commun.178(2008)852,https://doi.org/10.1016/j.cpc.2008.01.036, arXiv:0710.3820.

[56] CMSCollaboration,Eventgeneratortunesobtainedfromunderlyingeventand multipartonscatteringmeasurements,Eur.Phys.J.C76(2016)155,https:// doi.org/10.1140/epjc/s10052-016-3988-x,arXiv:1512.00815.

[57] S.Chatrchyan,etal.,CMS,Multiplicityandtransversemomentumdependence oftwo- andfour-particlecorrelationsinpPb andPbPb collisions,Phys.Lett. B724(2013)213,https://doi.org/10.1016/j.physletb.2013.06.028,arXiv:1305. 0609.

[58] M.J. Oreglia, A Study ofthe Reactions ψ→γ γψ, Ph.D. thesis, SLAC Re-portSLAC-R-236,StanfordUniversity,1980,http://www.slac.stanford.edu/pubs/ slacreports/slac-r-236.html,seeAppendixD.

[59] CMSCollaboration,Pseudorapiditydependenceoflong-rangetwo-particle cor-relationsinpPb collisionsat√sNN=5.02 TeV,Phys.Rev.C96(2017)014915,

https://doi.org/10.1103/PhysRevC.96.014915,arXiv:1604.05347.

[60]CMSCollaboration,Pseudorapidityandtransversemomentumdependenceof flowharmonicsinpPbandPbPbcollisions,arXiv:1710.07864,2017.

[61] B.I.Abelev,etal.,STAR,Mass,quark-number,and√sNNdependenceofthe sec-ondandfourthflowharmonicsinultra-relativisticnucleus-nucleuscollisions, Phys. Rev.C 75 (2007) 054906, https://doi.org/10.1103/PhysRevC.75.054906, arXiv:nucl-ex/0701010.

[62] A.Adare,etal.,PHENIX,ScalingpropertiesofazimuthalanisotropyinAu+Au andCu+Cucollisionsat√sNN=200GeV,Phys.Rev.Lett.98(2007)162301,

https://doi.org/10.1103/PhysRevLett.98.162301,arXiv:nucl-ex/0608033. [63] 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.

[64] V.Greco,C.M.Ko,P.Levai,Partoncoalescenceandanti-proton/pionanomaly atRHIC,Phys.Rev.Lett.90(2003)202302,https://doi.org/10.1103/PhysRevLett. 90.202302,arXiv:nucl-th/0301093.

[65] R.J.Fries,B.Muller,C.Nonaka,S.A.Bass,Hadronizationinheavyioncollisions: recombinationandfragmentationofpartons,Phys.Rev.Lett.90(2003)202303,

https://doi.org/10.1103/PhysRevLett.90.202303,arXiv:nucl-th/0301087. [66] J. Adams, et al., STAR, Particle type dependence of azimuthal anisotropy

and nuclear modification of particle production in Au + Au collisions at

√

sNN =200 GeV,Phys.Rev.Lett.92(2004)052302,https://doi.org/10.1103/

PhysRevLett.92.052302,arXiv:nucl-ex/0306007.

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,

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 S. 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 StateKeyLaboratoryofNuclearPhysicsandTechnology,PekingUniversity,Beijing,China

Y. Wang

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

Y. Assran9,10,S. Elgammal10, S. Khalil11

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

IRFU,CEA,UniversitéParis-Saclay,Gif-sur-Yvette,France

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

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

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, A. Ebrahimi, E. Garutti, D. Gonzalez, P. Gunnellini, J. Haller, A. Hinzmann, A. Karavdina, G. Kasieczka, R. Klanner, R. Kogler,N. Kovalchuk, S. Kurz, V. Kutzner, J. Lange,D. Marconi,J. Multhaup, M. Niedziela, C.E.N. Niemeyer,D. Nowatschin, A. Perieanu,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, 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

UniversityofDelhi,Delhi,India

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

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, Ravindra Kumar 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,F. Iemmia,b, S. Lo Meoa, S. Marcellinia, G. Masettia,A. Montanaria, F.L. Navarriaa,b, A. Perrottaa, F. Primaveraa,b,17,T. Rovellia,b, G.P. Sirolia,b,N. Tosia

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, 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. Pedrinia,S. Ragazzia,b,T. Tabarelli de Fatisa,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. Arcidiaconoa,c,S. Argiroa,b,M. Arneodoa,c,N. Bartosika,R. Bellana,b, C. Biinoa, 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 B. Francois,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

CentrodeInvestigacionydeEstudiosAvanzadosdelIPN,MexicoCity,Mexico

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

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 NationalResearchNuclearUniversity‘MoscowEngineeringPhysicsInstitute’(MEPhI),Moscow,Russia

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