UNIVERSIDADE ESTADUAL DE CAMPINAS
SISTEMA DE BIBLIOTECAS DA UNICAMP
REPOSITÓRIO DA PRODUÇÃO CIENTIFICA E INTELECTUAL DA UNICAMP
Versão do arquivo anexado / Version of attached file:
Versão do Editor / Published Version
Mais informações no site da editora / Further information on publisher's website:
https://www.sciencedirect.com/science/article/pii/S0370269318306622
DOI: 10.1016/j.physletb.2018.08.047
Direitos autorais / Publisher's copyright statement:
©2018
by Elsevier. All rights reserved.
DIRETORIA DE TRATAMENTO DA INFORMAÇÃO
Cidade Universitária Zeferino Vaz Barão Geraldo
CEP 13083-970 – Campinas SP
Fone: (19) 3521-6493
http://www.repositorio.unicamp.br
Physics Letters B 785 (2018) 419–428
Contents lists available atScienceDirect
Physics
Letters
B
www.elsevier.com/locate/physletb
Inclusive
J/
ψ
production
in
Xe–Xe
collisions
at
√
s
NN
=
5
.
44 TeV
.
ALICE
Collaboration
a
r
t
i
c
l
e
i
n
f
o
a
b
s
t
r
a
c
t
Articlehistory:
Received23May2018
Receivedinrevisedform26July2018 Accepted23August2018
Availableonline31August2018 Editor:W.-D.Schlatter
InclusiveJ/ψ productionisstudied inXe–Xe interactionsatacentre-of-massenergypernucleonpair of √sNN=5.44 TeV,using the ALICE detectorat the CERNLHC. The J/ψ meson is reconstructed via its decay into a muon pair, in the centre-of-mass rapidity interval 2.5<y<4 and down to zero transverse momentum.InthisLetter,thenuclearmodificationfactors RAAfor inclusiveJ/ψ,measured inthecentralityrange0–90%aswellasinthecentralityintervals0–20%and20–90%arepresented.The RAAvaluesarecomparedtopreviouslypublishedresultsforPb–Pb collisionsat√sNN=5.02 TeVandto thecalculationofatransportmodel.AgoodagreementisfoundbetweenXe–Xe andPb–Pb resultsas wellasbetweendataandthemodel.
©2018Organisationeuropéennepourlarecherchenucléaire.PublishedbyElsevierB.V.Thisisanopen accessarticleundertheCCBYlicense(http://creativecommons.org/licenses/by/4.0/).FundedbySCOAP3.
Thestudyoftheproductionofquarkoniumstatesplaysan im-portantroleinthecharacterizationofthepropertiesofthe Quark-Gluon Plasma (QGP) [1]. This state of matter, where quarks and gluonsarenot confinedinto hadrons, canbe produced in heavy-ion collisions at ultrarelativistic energies. Quarkonia are bound statesofheavyquark-antiquarkpairs(charmonia,cc and bottomo-nia,bb)and their productionrate issignificantly affected by the QGP. In particular, the color force responsible for the binding of heavyquarks isexpectedtobe screenedintheQGP, leading toa suppressionofquarkoniumproductionwhichcanberelatedtothe initialtemperatureofthesystem [2,3].Inaddition,atveryhigh en-ergies,suchasthoseavailableattheLHC,theabundantproduction ofcharm-anticharmpairsleadstoarecombinationprocess,which mayoccurbothintheQGPphaseorwhenthesystemcoolsdown andhadronsare formed out of the free quarksand gluons [4,5]. The study of the interplay between suppression and recombina-tionprocessesoffersthepossibilityofa quantitativeinvestigation oftheexistence of colorlessbound states ofheavy quarks inthe QGP.
An extended set of results was obtainedfor the J/
ψ
, a char-moniumstatewithquantumnumbers JPC=
1−−,atLHCenergies (√
sNN=
2.
76 and 5.02 TeV)in Pb–Pb collisions [6–12]. Compar-isonof these results to theoretical models [13–17] and to lower energydata [18,19] favorsthepicturedescribed above.The study ofthecollision ofnucleilighter than Pbmaygive additional im-portantinformationontherelativecontributionofsuppressionand recombinationmechanisms.AstepinthisdirectionisperformedinthisLetter,wherefirst resultsonJ/
ψ
productionatLHCenergiesinXe–Xe,acollisionsys- E-mailaddress:alice-publications@cern.ch.
tem ( AXe
=
129) lighter than Pb–Pb ( APb=
208), are presented. Data were collected by the ALICE Collaboration atthe centre-of-mass energy per nucleon pair√
sNN=
5.
44 TeV, during a short run carriedoutatthe endof2017.Dueto thelimitedintegrated luminosity,Lint∼
0.
34 μb−1,thestatisticaluncertaintiesare signif-icantlylargerthanthoseofthePb–Pb results [10],butnevertheless allowameaningfulcomparisonbetweenthetwosystems,interms ofthenuclearmodificationfactorRAA.Thisquantityisobtainedas theratio betweentheproductionyields innucleus–nucleus colli-sionsandthecorrespondingproton–proton(pp)crosssection, nor-malizedtothenuclearthicknessfunctionTAA[20].ValuesofRAA smaller(larger)thanunityindicatesuppression(enhancement) ef-fectsfor the particleunder study.The results shownin this Let-ter correspond to the centre-of-mass rapidity range 2.
5<
y<
4, areintegratedovertransversemomentum(pT)andwereobtained by studying the J/ψ
→
μ
+μ
− decay channel. The nuclear mod-ification factor is studied as a function of the centrality of the collision [21], expressed as a percentage of the hadronic Xe–Xe cross section. Theresults correspond toinclusive J/ψ
production, whichis thesumofa prompt component(directlyproduced J/ψ
andfeed-downfromothercharmoniumstates)andanon-prompt component,duetothedecayofparticlescontainingabquark.
ALICEistheLHCexperimentdedicatedtothestudyofnuclear collisions,andisdescribedindetailinRefs. [22,23].Themain de-tectorusedinthisanalysisisa muonspectrometer [24], covering thepseudorapidityrange
−
4<
η
<
−
2.
5.1 Itincludestrackingand trigger chambers, and reconstructs muons with pT larger than a1 IntheALICEreferenceframe,themuonspectrometercoversanegativeηrange
andconsequentlyanegativey range.Wehavechosentopresentourresultswitha positivey notation.
https://doi.org/10.1016/j.physletb.2018.08.047
0370-2693/©2018Organisationeuropéennepourlarecherchenucléaire.PublishedbyElsevierB.V.ThisisanopenaccessarticleundertheCCBYlicense (http://creativecommons.org/licenses/by/4.0/).FundedbySCOAP3.
Fig. 1. Fitstoinvariantmassdistributionsofopposite-signdimuons,for0–90%Xe–Xe collisions.Intheleftpanel,theresultofafittotherawinvariantmassspectrumis shown,whileintherightpanelthefittothesamedistributionaftersubtractionofthemixed-eventbackgroundispresented.Thefitcurvesshowninbluerepresentthesum ofthesignalandbackgroundshapes,whiletheredlinescorrespondtotheJ/ψsignalandthebluedashedonestothebackground(seetextfordetails).(Forinterpretation ofthecolorsinthefigure(s),thereaderisreferredtothewebversionofthisarticle.)
giventhreshold,whichis setatthe triggerlevel. Inaddition,the V0 [25], aset ofscintillator detectorscovering 2
.
8<
η
<
5.
1 and−
3.
7<
η
<
−
1.
7,isusedtodefinetheminimumbias(MB) inter-actiontriggervia acoincidenceofsignalsatpositive andnegativeη
values.The V0is alsousedforthe centralityestimate via afit ofthedistributionofthetotalsignalamplitudesintheframework oftheGlauber model [21].Thereconstructionoftheprimary col-lision vertexis carried out in the two layers ofthe Silicon Pixel Detector(SPD),theinnermostpartoftheInnerTrackingSystemof the experiment [26], covering|
η
|
<
2 and|
η
|
<
1.
4 respectively. Finally, rejection of non-hadronic Xe–Xe collisions is performed using the Zero Degree Calorimeters (ZDC) [27], which identifies electromagnetic interactions, while the V0 detects beam-gas col-lisionsoccurringoutsidethenominalinteractionpointregion.ThedataanalyzedinthisLetteraretakenwithatriggerformed by the coincidence of the MB trigger signal and of at least one muontriggeredinthemuonspectrometer, witha pT
=
0.
5 GeV/c threshold.Thedefinitionofthe triggerislessrestrictive thanthe oneusuallyadoptedforPb–Pb datataking(1GeV/c thresholdand twodetected muons),dueto themuch smallerinstantaneous lu-minosityforXe–Xe collisions. Standard selection criteria [10] are thenappliedtosucheventsandtothemuoncandidates.In partic-ular,it isrequired(i) that twoopposite-sign tracksreconstructed inthetrackingchambersofthemuonspectrometerarematchedto tracksegmentsinthetriggersystem,(ii)thatbothmuons belong-ingtothepair(dimuon)have−
4<
η
μ<
−
2.
5,and(iii)thattheir transverseposition Rabs attheendofthehadronabsorberofthe muonspectrometer satisfiesthecondition 17.
6<
Rabs<
89.
5 cm. Finally,thereconstructeddimuonshouldlayinthefiducial rapid-ityregionofthemuonspectrometer,2.
5<
y<
4.ThenuclearmodificationfactorRAAforthecollisionsystem un-derstudyisdefined,forthecentralityintervali,as
RiAA
=
N i J/ψ BRJ/ψ→μ+μ−NiMBAε
iTAAiσ
pp J/ψ,
(1)where NJi/ψ is the numberof detected J/
ψ
in the i-th centrality interval, BRJ/ψ→μ+μ−= (
5.
96±
0.
03)
% is the branching ratio of thedimuondecaychannel [28], NiMB isthenumberofMB events corresponding tothe analyzedtriggered eventsample, Aε
i istheproduct ofthe detector acceptancetimes the reconstruction effi-ciency,
TiAA
is the average nuclear thickness function [29], andσ
Jpp/ψ istheinclusiveJ/ψ
crosssectionforppcollisions,atthesame energy andin the same kinematic range asthe Xe–Xe data. Re-sults are given forthe centrality interval 0–90% andfor the two sub-intervals0–20%and20–90%.Exceptfor thedetermination of
σ
Jpp/ψ,the other quantitiesen-teringthedefinitionofRAA areevaluatedfollowingthesame pro-cedureusedfortheanalysisofthePb–Pb datasampleanddetailed inRef. [10].
The extraction of NJ/ψ is performed with two different
ap-proaches.Inthefirst,therawopposite-signdimuoninvariantmass distribution isfittedwitha superpositionofresonanceand back-groundshapes [30], theformerbeingtuned toMonteCarlo(MC) simulations and the latter corresponding to empirical functions. Inthe second,thebackgroundisestimatedvia amixed-event in-variant mass distribution, obtained from the collected sample of muon-triggered eventsandsubtractedfromtherawspectrum [9]. The resultingdistribution is then fitted withthe sum of a reso-nance shape and a continuum function accountingfor the small residual backgroundcomponent. Duetothe low statistical signif-icance of the present data sample, the widthof the J/
ψ
meson, which is usually kept asa free parameter in the invariant mass fits, is fixed toσ
J/ψ=
70 MeV/c2, corresponding to the value ofthis quantity obtained in previous analyses [10,31,32]. For each of the two approaches, several fits were performed varying the fit mass range, the signal and background shapes and the J/
ψ
widthby
±
1 MeV/c2.Theobtainedvalue forthecentrality inter-val0–90% isNJ/ψ=
241±
47(
stat.)
±
26(
syst.)
,wherethecentralvalue andthestatisticaluncertaintycorrespond tothe averageof the fit results and to the average of the corresponding statisti-cal uncertainties, respectively. The systematic uncertainty is ob-tained as the root mean square of the distribution of the NJ/ψ
values obtained with the various fits. The corresponding values for the 0–20% and 20–90% centrality sub-intervals are NJ/ψ
=
175
±
42(
stat.)
±
23(
syst.)
andNJ/ψ=
77±
20(
stat.)
±
7(
syst.)
,re-spectively.
Fig.1showsasanexampletheresultsoftwofitstothe0–90% Xe–Xedimuoninvariantmassdistribution,correspondingtofitting therawspectrum(leftpanel)orthemixed-eventbackground sub-tractedmassdistribution(rightpanel).
The product of the acceptance times the reconstruction effi-ciency A
ε
for J/ψ
is evaluated via a MC simulation, based on the GEANT3 transport model [33], which takes into account theALICE Collaboration / Physics Letters B 785 (2018) 419–428 421
alignmentofthemuonspectrometerdetectorsandtheirefficiency. The input pT and y distributions forthe J/
ψ
acceptance calcula-tion cannot be tuned directly to data, dueto the low integrated luminosity of the data sample. It is therefore assumed that the shapeofthey andpTdistributionsissimilarfordifferentcollision systemsincentralityintervalscorrespondingto thesameaverage number of participant nucleons, weighted by the corresponding number of nucleon–nucleon collisions, Npartw . The weighting is introducedtotakeintoaccountthattheJ/ψ
productioncross sec-tionis proportional to the numberof nucleon–nucleon collisions and that therefore the average Npart in wide centrality bins is systematicallyshifted towards highervalues.Followingthis argu-ment,thedifferentialdistributionsmeasuredinPb–Pb collisionsat√
sNN
=
5.
02 TeV[10] forthe20–40%centralityrangeareusedas input distribution for the MC calculation, since Nwpart
PbPb,20−40% isequal,within∼
2%,toNwpart
XeXe,0−90%,estimatedviaaGlauber MCcalculation.The systematicuncertaintyontheJ/ψ
acceptance value due to the choice of the J/ψ
rapidity and transverse mo-mentumdistributionsamountsto2%andisevaluatedbychoosing alternative input shapes corresponding to other Pb–Pb centrality ranges.Concerningthereconstructionefficiency,itslightlydependson thecollisioncentrality,duetothedetectoroccupancyinthemuon spectrometer. The effect was evaluated in the analysis of Pb–Pb events [10] byembeddingthesimulatedJ/
ψ
signalintorealevents corresponding to various centralities. For this analysis, starting fromthePb–Pb results,thedecreasein Aε
XeXe,0−90% withrespect toasimulationcontainingonlyJ/ψ
isestimatedtobe4.2%(values for0–20%and20–90%centralityrangesare5.5%and1.6%, respec-tively).Thesystematicuncertaintyonthereconstructionefficiency isevaluatedfollowingtheprocedureusedinRef. [10],leadingtoa 3.6%effect.Theresultingvaluefortheproductofacceptancetimes recon-structionefficiencyfor J/
ψ
productionin 0–90% Xe–Xe collisions is Aε
XeXe,0−90%=
0.
228±
0.
009(
syst.)
,withanegligiblestatistical uncertainty.The normalizationfactor NMB is evaluated by multiplying the numberof opposite-sign dimuon triggers by a factor Fnorm, cor-responding to the inverse of the probability of having a trig-geredmuon in a MB event. Thisquantity is computedfrom the eventtrigger inputinformation andthe level-0triggermask. The procedure and the evaluation of the systematic uncertainty are described in Ref. [10]. The obtained value is Fnorm
=
2.
428±
0.
001(
stat.)
±
0.
024(
syst.)
.The reference cross section for the calculation of RAA is ob-tainedstartingfromthemeasuredvalueoftheinclusiveJ/
ψ
cross sectioninppcollisionsat√
s=
5.
02 TeV [10].Thisquantityisthen correctedtoaccountforthedifferentcentre-of-massenergyofthe Xe–Xe data, using an interpolation of available ALICEpp results at√
s=
2.76, 5.02, 7, 8 and 13 TeV [32]. The obtained value isσ
Jpp/ψ=
5.
99±
0.
09(
stat.)
±
0.
30(
syst.)
μb−1,wherethesystematic uncertaintycontains asmallterm(0.4%)relatedto the interpola-tionprocedure,calculatedasthemaximumspreadbetweenresults obtainedwithvariousinterpolatingfunctions [34].Thenuclear thickness function
TAA is evaluated forthe var-ious centrality intervalsvia a Glauber model calculation, and its uncertaintyisestimatedbyvarying withinuncertainties the den-sity parameters of the Xe nucleus [29,35]. For 0–90% centrality itsvalue amountsto TAA=
3.
25±
0.
25 mb−1,while for0–20% and20–90% one obtains TAA=
9.
90±
0.
62 mb−1 and TAA=
1.
35±
0.
14 mb−1,respectively.Finally,a systematicuncertainty on the definitionof the cen-tralityintervalsisevaluatedbyvarying thevalueoftheV0signal amplitudecorresponding to90% centralityby
±
0.
5%and recalcu-latingcorrespondinglythecentralityintervals.Table 1
Summaryofsystematicuncertaintiesonthecalculationofthe nu-clearmodificationfactors.Thetrackingefficiencytermincludesa 1%contributionduetothechoiceoftheχ2cutofthematching
betweentheinformationoftrackingandtriggerdetectors.Allthe uncertaintiesarecorrelatedamongthevariouscentralityranges, exceptthoseonthesignalextraction,TAAandthedefinitionof
thecentralityintervals.
Source 0–90% 0–20% 20–90% Signal extraction 11% 13% 8% MC input 2% 2% 2% Tracking efficiency 2% 2% 2% Trigger efficiency 3% 3% 3% Fnorm 1% 1% 1% TAA 8% 6% 10% Centrality 0% 0% 1% pp reference 5% 5% 5%
Fig. 2. TheinclusiveJ/ψ nuclearmodificationfactorforXe–Xe collisionsat√sNN=
5.44 TeV.TheresultsareplottedusingascentralityvariableNw
part,obtainedby
weighting,ineachcentralityinterval,theNpartdistributionwiththe
correspond-ingdistributionofthenumberofnucleon–nucleoncollisions.Theerrorbars rep-resentthe statisticaluncertainties,theboxesaroundthe pointsthe uncorrelated systematicuncertainties.Correlateduncertaintiesareshownasafilledboxaround unity.The results arecomparedwith the samequantityfor Pb–Pb collisionsat √s
NN=5.02 TeV [10] andtotheresultsofthecalculationofatransportmodel [13, 14].ForPb–Pb,theweightingofNpartwiththenumberofnucleon–nucleon
colli-sionswasnotperformed,sinceitleadstoanegligibleeffectwhenthecentrality intervalsarenarrow.
Table 1 showsa summary of the systematicuncertainties for the RAA measurement for the three analyzed centrality ranges. Themaincontributionscomefromtheestimateof
TAAandfrom thesignal extraction.The formerisdominatedby theuncertainty onthe surfacethicknessofthe Xenucleus. Thelatter,being esti-matedinadata-drivenwayasdetailedabove,maysufferfromthe statistical limitations of the data sample. The quoted values can thereforebeconsideredtobeaconservativeestimate.The pT-integratednuclearmodificationfactorforinclusiveJ/
ψ
production in Xe–Xe collisions at
√
sNN=
5.
44 TeV, measured in 2.
5<
y<
4 and in the 0–90% centrality range, is RAA=
0.
54±
0.
11(
stat.)
±
0.
08(
syst.)
. Thisvalue can becompared with the corresponding one for Pb–Pb collisions at√
sNN=
5.
02 TeV, RPbPbAA=
0.
65±
0.
01(
stat.)
±
0.
04(
syst.)
[10].Theirratioamountsto 0.
84±
0.
16(
stat.)
±
0.
13(
syst.)
,showingthatthetwovaluesagree within about 0.8σ
.Following the approach ofRef. [9], it can be shownthattheXe–Xe nuclearmodificationfactorforpromptJ/ψ
could be up to 10% higher (lower) than the inclusive RAA if the non-promptJ/
ψ
componentfromthedecaysofhadronscontaining abquarkisnot(completely)suppressed.InFig.2the RAA values for0–20%and20–90%Xe–Xe collisionsareplotted,andcomparedwith the centrality dependence of the nuclear modification fac-tor for Pb–Pb collisions [10]. The latter shows, after a decrease up to Npart
∼
100, a saturation at RAA∼
0.65–0.7 towards more centralevents,andthetwoXe–Xe pointsarefoundtobein agree-ment,withintheirlargeruncertainties,withthePb–Pb results.The Xe–Xe andPb–Pb resultsarealsocomparedwiththecalculationof atransportmodelbyDuandRapp [13,14].Aclosesimilarityofthe predictedsuppression patternsforPb–Pb and Xe–Xe is observed, whichfairlyreproducestheexperimentalresults.In summary, we have measured inclusive J/
ψ
production in Xe–Xe collisionsat√
sNN=
5.
44 TeV.Resultsonthenuclear mod-ification factors were given for various centrality selections and comparedtocorresponding resultsforPb–Pb collisionsat√
sNN=
5.
02 TeVandtoatheoreticalmodel.Withintheexperimental un-certainties,agoodagreementisfoundbetweenthe RAAmeasured inthe two systems andwiththe calculation. Theseresults show thattherelativecontributionofsuppressionandregeneration pro-cessesissimilarforcollisionsproducingsimilar Npart valuesfrom differentcollisionsystems.Acknowledgements
The ALICE Collaboration would like to thank all its engineers andtechnicians fortheir invaluablecontributionstothe construc-tionoftheexperimentandtheCERNacceleratorteamsforthe out-standingperformanceoftheLHCcomplex.TheALICECollaboration gratefully acknowledges the resources and support provided by all Gridcentres andtheWorldwide LHCComputing Grid(WLCG) collaboration. The ALICE Collaboration acknowledges the follow-ingfundingagenciesfortheirsupportinbuildingandrunningthe ALICEdetector:A.I. AlikhanyanNationalScience Laboratory (Yere-vanPhysicsInstitute) Foundation(ANSL),State Committee of Sci-enceandWorldFederationofScientists(WFS),Armenia; Austrian AcademyofSciencesandNationalstiftungfürForschung, Technolo-gie und Entwicklung, Austria; Ministry of Communications and High Technologies, NationalNuclear Research Center, Azerbaijan; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Universidade Federal do Rio Grande do Sul (UFRGS), Fi-nanciadoradeEstudoseProjetos(Finep)andFundaçãodeAmparo à Pesquisa do Estado de São Paulo (FAPESP), Brazil; Ministry of Science & Technology of China (MSTC), National Natural Science Foundation of China (NSFC) and Ministry of Education of China (MOEC), China; Ministry of Science andEducation, Croatia; Min-istryofEducation,YouthandSportsoftheCzech Republic,Czech Republic; The Danish Council for Independent Research – Natu-ral Sciences, the Carlsberg Foundation and Danish National Re-search Foundation (DNRF), Denmark;Helsinki Institute ofPhysics (HIP),Finland;Commissariatàl’EnergieAtomique(CEA)and Insti-tut Nationalde Physique Nucléaire etde Physique desParticules (IN2P3)and Centre Nationalde laRecherche Scientifique(CNRS), France; Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie (BMBF) and GSI Helmholtzzentrum für Schw-erionenforschung GmbH, Germany; General Secretariat for Re-search andTechnology, Ministryof Education,Research and Reli-gions,Greece;NationalResearch,DevelopmentandInnovation Of-fice,Hungary;DepartmentofAtomicEnergy,GovernmentofIndia (DAE),DepartmentofScienceandTechnology,GovernmentofIndia (DST), University GrantsCommission, Governmentof India(UGC) andCouncilofScientific andIndustrial Research(CSIR),India; In-donesian Institute of Science, Indonesia; Centro Fermi – Museo StoricodellaFisicaeCentroStudieRicercheEnricoFermiand Isti-tutoNazionalediFisicaNucleare(INFN),Italy;Institutefor Innova-tiveScienceandTechnology,NagasakiInstitute ofAppliedScience (IIST),Japan SocietyforthePromotionofScience (JSPS)KAKENHI and Japanese Ministry of Education, Culture, Sports, Science and
Technology (MEXT), Japan; Consejo Nacional de Ciencia (CONA-CYT)yTecnología,throughFondodeCooperaciónInternacionalen Ciencia yTecnología(FONCICYT) andDirección Generalde Asun-tos delPersonalAcademico(DGAPA),Mexico;Nederlandse Organ-isatie voorWetenschappelijkOnderzoek (NWO),Netherlands; The ResearchCouncilofNorway,Norway;CommissiononScienceand Technology forSustainableDevelopmentintheSouth(COMSATS), Pakistan;PontificiaUniversidadCatólicadelPerú,Peru;Ministryof ScienceandHigherEducationandNationalScienceCentre,Poland; KoreaInstituteofScienceandTechnologyInformationandNational ResearchFoundationofKorea(NRF),RepublicofKorea;Ministryof Education andScientific Research,Institute ofAtomicPhysicsand RomanianNationalAgencyforScience,TechnologyandInnovation, Romania; Joint Institute for Nuclear Research (JINR), Ministry of EducationandScienceoftheRussianFederationandNational Re-search Centre Kurchatov Institute, Russia; Ministry of Education, Science, ResearchandSportof theSlovak Republic, Slovakia; Na-tionalResearchFoundationofSouthAfrica,SouthAfrica;Centrode AplicacionesTecnológicasyDesarrolloNuclear (CEADEN), Cubaen-ergía,CubaandCentrodeInvestigacionesEnergéticas, Medioambi-entales yTecnológicas(CIEMAT),Spain;SwedishResearchCouncil (VR)andKnut&AliceWallenbergFoundation(KAW),Sweden; Eu-ropean Organization for Nuclear Research, Switzerland; National Science andTechnology Development Agency (NSDTA), Suranaree University of Technology (SUT) and Office of the Higher Educa-tionCommissionunderNRUprojectofThailand,Thailand;Turkish Atomic Energy Agency (TAEK), Turkey;National Academy of Sci-encesofUkraine,Ukraine;ScienceandTechnologyFacilities Coun-cil (STFC), United Kingdom; National Science Foundation of the United States ofAmerica (NSF) andUnited StatesDepartment of Energy,OfficeofNuclearPhysics(DOENP),UnitedStatesof Amer-ica.
References
[1]E.V.Shuryak,Quark-gluonplasmaandhadronicproductionofleptons,photons andpsions,Phys.Lett.B78(1978)150,Yad.Fiz.28(1978)796.
[2]T.Matsui,H.Satz, J/ψ suppressionbyquark-gluonplasmaformation,Phys. Lett.B178(1986)416.
[3]S.Digal,P.Petreczky,H.Satz,Quarkoniumfeeddownandsequential suppres-sion,Phys.Rev.D64(2001)094015,arXiv:hep-ph/0106017 [hep-ph]. [4]P.Braun-Munzinger,J.Stachel,(Non)thermalaspectsofcharmonium
produc-tionandanewlookat J/ψsuppression,Phys.Lett.B490(2000)196–202. [5]R.L.Thews,M.Schroedter,J.Rafelski,Enhanced J/ψproductionindeconfined
quarkmatter,Phys.Rev.C63(2001)054905,arXiv:hep-ph/0007323 [hep-ph]. [6]ALICECollaboration,B.Abelev,etal., J/ψ suppressionatforwardrapidityin Pb–Pbcollisionsat√sN N=2.76 TeV,Phys.Rev.Lett.109(2012)072301,arXiv:
1202.1383 [hep-ex].
[7]CMS Collaboration, S. Chatrchyan,et al., Suppression of non-prompt J/ψ, prompt J/ψ,andY(1S)inPbPbcollisionsat√sN N=2.76 TeV,J.HighEnergy
Phys.05(2012)063,arXiv:1201.5069 [nucl-ex].
[8]ALICECollaboration,B.Abelev,etal.,Centrality,rapidityand transverse mo-mentum dependence of J/ψ suppression in Pb–Pb collisions at √sN N =
2.76 TeV,Phys.Lett.B743(2014)314–327,arXiv:1311.0214 [nucl-ex]. [9]ALICECollaboration,J.Adam,etal., DifferentialstudiesofinclusiveJ/ψ and
ψ(2S)productionatforwardrapidityinPb–Pbcollisionsat√sNN=2.76 TeV,
J.HighEnergyPhys.05(2016)179,arXiv:1506.08804 [nucl-ex].
[10]ALICECollaboration,J.Adam,etal.,J/ψsuppressionatforwardrapidityinPb– Pbcollisionsat √sNN=5.02 TeV,Phys. Lett.B766(2017)212–224, arXiv:
1606.08197 [nucl-ex].
[11]CMS Collaboration, V. Khachatryan, et al., Suppression and azimuthal anisotropyofpromptand nonprompt J/ψ production in PbPbcollisionsat √
sNN=2.76 TeV,Eur.Phys.J.C77 (4)(2017)252,arXiv:1610.00613 [nucl-ex].
[12]CMSCollaboration,A.M.Sirunyan,et al., Measurementofpromptand non-promptcharmoniumsuppressioninPbPbcollisionsat5.02TeV,arXiv:1712. 08959 [nucl-ex].
[13]X.Zhao,R.Rapp,MediummodificationsandproductionofcharmoniaatLHC, Nucl.Phys.A859(2011)114–125,arXiv:1102.2194 [hep-ph].
[14]X.Du,R.Rapp,Sequentialregenerationofcharmoniainheavy-ioncollisions, Nucl.Phys.A943(2015)147–158,arXiv:1504.00670 [hep-ph].
[15]A.Andronic,P.Braun-Munzinger,K.Redlich,J.Stachel,Thestatisticalmodelin Pb–PbcollisionsattheLHC,Nucl.Phys.A904–905(2013)535c–538c,arXiv: 1210.7724 [nucl-th].
ALICE Collaboration / Physics Letters B 785 (2018) 419–428 423
[16]E.G.Ferreiro,Excitedcharmoniumsuppressioninproton-nucleuscollisionsas aconsequenceofcomovers,Phys.Lett.B749(2015)98–103,arXiv:1411.0549 [hep-ph].
[17]K.Zhou,N.Xu,Z.Xu,P.Zhuang,Mediumeffectsoncharmoniumproduction atultrarelativisticenergiesavailableattheCERNLargeHadronCollider,Phys. Rev.C89 (5)(2014)054911,arXiv:1401.5845 [nucl-th].
[18]PHENIXCollaboration,A.Adare,etal., J/ψ suppressionatforwardrapidityin Au+Aucollisionsat √sN N=200 GeV,Phys.Rev.C84(2011)054912,arXiv:
1103.6269 [nucl-ex].
[19]STARCollaboration,B.I.Abelev,etal.,J/ψ productionathightransverse mo-mentuminp+pand Cu+Cucollisions at √sNN=200 GeV, Phys.Rev.C80
(2009)041902,arXiv:0904.0439 [nucl-ex].
[20]M.L.Miller,K.Reygers,S.J.Sanders,P.Steinberg,Glaubermodelinginhigh en-ergynuclearcollisions,Annu.Rev.Nucl.Part.Sci.57(2007)205–243,arXiv: nucl-ex/0701025 [nucl-ex].
[21]ALICECollaboration,B.Abelev,et al.,CentralitydeterminationofPb–Pb col-lisionsat √sN N=2.76 TeV withALICE,Phys. Rev.C88 (4)(2013)044909,
arXiv:1301.4361 [nucl-ex].
[22]ALICECollaboration,K.Aamodt,etal.,TheALICEexperimentattheCERNLHC, J.Instrum.3(2008)S08002.
[23]ALICECollaboration,B.Abelev,etal.,PerformanceoftheALICEexperimentat theCERNLHC,Int.J.Mod.Phys.A29(2014)1430044,arXiv:1402.4476 [nucl -ex].
[24] ALICECollaboration,K.Aamodt,etal.,Rapidityandtransversemomentum de-pendenceofinclusiveJ/ψproductioninppcollisionsat√s=7 TeV,Phys.Lett. B704(2011)442–455,http://arxiv.org/abs/1105.0380.
[25]ALICECollaboration,E.Abbas,etal.,PerformanceoftheALICEVZEROsystem, J.Instrum.8(2013)P10016,arXiv:1306.3130 [nucl-ex].
[26]ALICECollaboration,K.Aamodt,etal.,AlignmentoftheALICEinnertracking systemwithcosmic-raytracks,J.Instrum.5(2010)P03003,arXiv:1001.0502 [physics.ins-det].
[27]ALICECollaboration,B.Abelev,etal.,Measurementofthecrosssectionfor elec-tromagneticdissociationwithneutronemissioninPb–Pbcollisionsat√sN N=
2.76 TeV,Phys.Rev.Lett.109(2012)252302,arXiv:1203.2436 [nucl-ex]. [28]Particle Data Group Collaboration, C. Patrignani, et al., Review ofparticle
physics,Chin.Phys.C40 (10)(2016)100001.
[29] ALICECollaboration,CentralitydeterminationusingtheGlaubermodelinXe– Xecollisionsat√sNN=5.44 TeV,http://cds.cern.ch/record/2315401.
[30]ALICE Collaboration, Quarkonium signal extractionin ALICE, ALICE-PUBLIC-2015-006,2015.
[31]ALICECollaboration,B.Abelev,etal., J/ψ productionandnucleareffectsin p-Pbcollisions at√sNN=5.02 TeV,J. HighEnergyPhys. 1402(2014) 073,
arXiv:1308.6726 [nucl-ex].
[32]ALICECollaboration,S.Acharya,etal.,Energydependenceofforward-rapidity J/ψ andψ(2S)productioninppcollisionsattheLHC,Eur.Phys.J.C77 (6) (2017)392,arXiv:1702.00557 [hep-ex].
[33]R.Brun,F.Carminati,S.Giani,GEANTDetectorDescriptionandSimulationTool, CERNProgramLibraryLongWriteup,CERN-W5013,1994.
[34] ALICECollaboration,LHCbCollaboration,Reference pp cross-sectionsfor J/ψ studiesinproton-leadcollisionsat√sN N=5.02 TeVandcomparisonsbetween
ALICEandLHCbresults,http://cds.cern.ch/record/1639617,CONF-2013-013. [35]C.Loizides,J.Kamin,D.d’Enterria,ImprovedMonteCarloGlauberpredictions
at present andfuture nuclearcolliders,Phys. Rev.C97 (5)(2018)054910, arXiv:1710.07098 [nucl-ex].
ALICECollaboration
S. Acharya
139,
F.T.-. Acosta
22,
D. Adamová
94,
J. Adolfsson
81,
M.M. Aggarwal
98,
G. Aglieri Rinella
36,
M. Agnello
33,
N. Agrawal
49,
Z. Ahammed
139,
S.U. Ahn
77,
S. Aiola
144,
A. Akindinov
65,
M. Al-Turany
104,
S.N. Alam
139,
D.S.D. Albuquerque
120,
D. Aleksandrov
88,
B. Alessandro
59,
R. Alfaro Molina
73,
Y. Ali
16,
A. Alici
11,
54,
29,
A. Alkin
3,
J. Alme
24,
T. Alt
70,
L. Altenkamper
24,
I. Altsybeev
138,
M.N. Anaam
7,
C. Andrei
48,
D. Andreou
36,
H.A. Andrews
108,
A. Andronic
142,
104,
M. Angeletti
36,
V. Anguelov
102,
C. Anson
17,
T. Antiˇci ´c
105,
F. Antinori
57,
P. Antonioli
54,
R. Anwar
124,
N. Apadula
80,
L. Aphecetche
112,
H. Appelshäuser
70,
S. Arcelli
29,
R. Arnaldi
59,
O.W. Arnold
103,
115,
I.C. Arsene
23,
M. Arslandok
102,
B. Audurier
112,
A. Augustinus
36,
R. Averbeck
104,
M.D. Azmi
18,
A. Badalà
56,
Y.W. Baek
61,
42,
S. Bagnasco
59,
R. Bailhache
70,
R. Bala
99,
A. Baldisseri
134,
M. Ball
44,
R.C. Baral
86,
A.M. Barbano
28,
R. Barbera
30,
F. Barile
53,
L. Barioglio
28,
G.G. Barnaföldi
143,
L.S. Barnby
93,
V. Barret
131,
P. Bartalini
7,
K. Barth
36,
E. Bartsch
70,
N. Bastid
131,
S. Basu
141,
G. Batigne
112,
B. Batyunya
76,
P.C. Batzing
23,
J.L. Bazo Alba
109,
I.G. Bearden
89,
H. Beck
102,
C. Bedda
64,
N.K. Behera
61,
I. Belikov
133,
F. Bellini
36,
H. Bello Martinez
2,
R. Bellwied
124,
L.G.E. Beltran
118,
V. Belyaev
92,
G. Bencedi
143,
S. Beole
28,
A. Bercuci
48,
Y. Berdnikov
96,
D. Berenyi
143,
R.A. Bertens
127,
D. Berzano
36,
59,
L. Betev
36,
P.P. Bhaduri
139,
A. Bhasin
99,
I.R. Bhat
99,
H. Bhatt
49,
B. Bhattacharjee
43,
J. Bhom
116,
A. Bianchi
28,
L. Bianchi
124,
N. Bianchi
52,
J. Bielˇcík
39,
J. Bielˇcíková
94,
A. Bilandzic
115,
103,
G. Biro
143,
R. Biswas
4,
S. Biswas
4,
J.T. Blair
117,
D. Blau
88,
C. Blume
70,
G. Boca
136,
F. Bock
36,
A. Bogdanov
92,
L. Boldizsár
143,
M. Bombara
40,
G. Bonomi
137,
M. Bonora
36,
H. Borel
134,
A. Borissov
20,
142,
M. Borri
126,
E. Botta
28,
C. Bourjau
89,
L. Bratrud
70,
P. Braun-Munzinger
104,
M. Bregant
119,
T.A. Broker
70,
M. Broz
39,
E.J. Brucken
45,
E. Bruna
59,
G.E. Bruno
36,
35,
D. Budnikov
106,
H. Buesching
70,
S. Bufalino
33,
P. Buhler
111,
P. Buncic
36,
O. Busch
130,
i,
Z. Buthelezi
74,
J.B. Butt
16,
J.T. Buxton
19,
J. Cabala
114,
D. Caffarri
90,
H. Caines
144,
A. Caliva
104,
E. Calvo Villar
109,
R.S. Camacho
2,
P. Camerini
27,
A.A. Capon
111,
F. Carena
36,
W. Carena
36,
F. Carnesecchi
29,
11,
J. Castillo Castellanos
134,
A.J. Castro
127,
E.A.R. Casula
55,
C. Ceballos Sanchez
9,
S. Chandra
139,
B. Chang
125,
W. Chang
7,
S. Chapeland
36,
M. Chartier
126,
S. Chattopadhyay
139,
S. Chattopadhyay
107,
A. Chauvin
103,
115,
C. Cheshkov
132,
B. Cheynis
132,
V. Chibante Barroso
36,
D.D. Chinellato
120,
S. Cho
61,
P. Chochula
36,
T. Chowdhury
131,
P. Christakoglou
90,
C.H. Christensen
89,
P. Christiansen
81,
T. Chujo
130,
S.U. Chung
20,
C. Cicalo
55,
L. Cifarelli
11,
29,
F. Cindolo
54,
J. Cleymans
123,
F. Colamaria
53,
D. Colella
66,
36,
53,
A. Collu
80,
M. Colocci
29,
M. Concas
59,
ii,
G. Conesa Balbastre
79,
Z. Conesa del Valle
62,
J.G. Contreras
39,
T.M. Cormier
95,
Y. Corrales Morales
59,
P. Cortese
34,
M.R. Cosentino
121,
F. Costa
36,
S. Costanza
136,
J. Crkovská
62,
P. Crochet
131,
E. Cuautle
71,
I. Das
107,
S. Das
4,
A. Dash
86,
S. Dash
49,
S. De
50,
A. De Caro
32,
G. de Cataldo
53,
C. de Conti
119,
J. de Cuveland
41,
A. De Falco
26,
D. De Gruttola
11,
32,
N. De Marco
59,
S. De Pasquale
32,
R.D. De Souza
120,
H.F. Degenhardt
119,
A. Deisting
104,
102,
A. Deloff
85,
S. Delsanto
28,
C. Deplano
90,
P. Dhankher
49,
D. Di Bari
35,
A. Di Mauro
36,
B. Di Ruzza
57,
R.A. Diaz
9,
T. Dietel
123,
P. Dillenseger
70,
Y. Ding
7,
R. Divià
36,
Ø. Djuvsland
24,
A. Dobrin
36,
D. Domenicis Gimenez
119,
B. Dönigus
70,
O. Dordic
23,
L.V.R. Doremalen
64,
A.K. Dubey
139,
A. Dubla
104,
L. Ducroux
132,
S. Dudi
98,
A.K. Duggal
98,
M. Dukhishyam
86,
P. Dupieux
131,
R.J. Ehlers
144,
D. Elia
53,
E. Endress
109,
H. Engel
75,
E. Epple
144,
B. Erazmus
112,
F. Erhardt
97,
M.R. Ersdal
24,
B. Espagnon
62,
G. Eulisse
36,
J. Eum
20,
D. Evans
108,
S. Evdokimov
91,
L. Fabbietti
103,
115,
M. Faggin
31,
J. Faivre
79,
A. Fantoni
52,
M. Fasel
95,
L. Feldkamp
142,
A. Feliciello
59,
G. Feofilov
138,
A. Fernández Téllez
2,
A. Ferretti
28,
A. Festanti
31,
36,
V.J.G. Feuillard
102,
J. Figiel
116,
M.A.S. Figueredo
119,
S. Filchagin
106,
D. Finogeev
63,
F.M. Fionda
24,
G. Fiorenza
53,
F. Flor
124,
M. Floris
36,
S. Foertsch
74,
P. Foka
104,
S. Fokin
88,
E. Fragiacomo
60,
A. Francescon
36,
A. Francisco
112,
U. Frankenfeld
104,
G.G. Fronze
28,
U. Fuchs
36,
C. Furget
79,
A. Furs
63,
M. Fusco Girard
32,
J.J. Gaardhøje
89,
M. Gagliardi
28,
A.M. Gago
109,
K. Gajdosova
89,
M. Gallio
28,
C.D. Galvan
118,
P. Ganoti
84,
C. Garabatos
104,
E. Garcia-Solis
12,
K. Garg
30,
C. Gargiulo
36,
P. Gasik
115,
103,
E.F. Gauger
117,
M.B. Gay Ducati
72,
M. Germain
112,
J. Ghosh
107,
P. Ghosh
139,
S.K. Ghosh
4,
P. Gianotti
52,
P. Giubellino
104,
59,
P. Giubilato
31,
P. Glässel
102,
D.M. Goméz Coral
73,
A. Gomez Ramirez
75,
V. Gonzalez
104,
P. González-Zamora
2,
S. Gorbunov
41,
L. Görlich
116,
S. Gotovac
37,
V. Grabski
73,
L.K. Graczykowski
140,
K.L. Graham
108,
L. Greiner
80,
A. Grelli
64,
C. Grigoras
36,
V. Grigoriev
92,
A. Grigoryan
1,
S. Grigoryan
76,
J.M. Gronefeld
104,
F. Grosa
33,
J.F. Grosse-Oetringhaus
36,
R. Grosso
104,
R. Guernane
79,
B. Guerzoni
29,
M. Guittiere
112,
K. Gulbrandsen
89,
T. Gunji
129,
A. Gupta
99,
R. Gupta
99,
I.B. Guzman
2,
R. Haake
36,
M.K. Habib
104,
C. Hadjidakis
62,
H. Hamagaki
82,
G. Hamar
143,
M. Hamid
7,
J.C. Hamon
133,
R. Hannigan
117,
M.R. Haque
64,
J.W. Harris
144,
A. Harton
12,
H. Hassan
79,
D. Hatzifotiadou
54,
11,
S. Hayashi
129,
S.T. Heckel
70,
E. Hellbär
70,
H. Helstrup
38,
A. Herghelegiu
48,
E.G. Hernandez
2,
G. Herrera Corral
10,
F. Herrmann
142,
K.F. Hetland
38,
T.E. Hilden
45,
H. Hillemanns
36,
C. Hills
126,
B. Hippolyte
133,
B. Hohlweger
103,
D. Horak
39,
S. Hornung
104,
R. Hosokawa
130,
79,
J. Hota
67,
P. Hristov
36,
C. Huang
62,
C. Hughes
127,
P. Huhn
70,
T.J. Humanic
19,
H. Hushnud
107,
N. Hussain
43,
T. Hussain
18,
D. Hutter
41,
D.S. Hwang
21,
J.P. Iddon
126,
S.A. Iga Buitron
71,
R. Ilkaev
106,
M. Inaba
130,
M. Ippolitov
88,
M.S. Islam
107,
M. Ivanov
104,
V. Ivanov
96,
V. Izucheev
91,
B. Jacak
80,
N. Jacazio
29,
P.M. Jacobs
80,
M.B. Jadhav
49,
S. Jadlovska
114,
J. Jadlovsky
114,
S. Jaelani
64,
C. Jahnke
119,
115,
M.J. Jakubowska
140,
M.A. Janik
140,
C. Jena
86,
M. Jercic
97,
O. Jevons
108,
R.T. Jimenez Bustamante
104,
M. Jin
124,
P.G. Jones
108,
A. Jusko
108,
P. Kalinak
66,
A. Kalweit
36,
J.H. Kang
145,
V. Kaplin
92,
S. Kar
7,
A. Karasu Uysal
78,
O. Karavichev
63,
T. Karavicheva
63,
P. Karczmarczyk
36,
E. Karpechev
63,
U. Kebschull
75,
R. Keidel
47,
D.L.D. Keijdener
64,
M. Keil
36,
B. Ketzer
44,
Z. Khabanova
90,
A.M. Khan
7,
S. Khan
18,
S.A. Khan
139,
A. Khanzadeev
96,
Y. Kharlov
91,
A. Khatun
18,
A. Khuntia
50,
M.M. Kielbowicz
116,
B. Kileng
38,
B. Kim
130,
D. Kim
145,
D.J. Kim
125,
E.J. Kim
14,
H. Kim
145,
J.S. Kim
42,
J. Kim
102,
M. Kim
61,
102,
S. Kim
21,
T. Kim
145,
T. Kim
145,
S. Kirsch
41,
I. Kisel
41,
S. Kiselev
65,
A. Kisiel
140,
J.L. Klay
6,
C. Klein
70,
J. Klein
36,
59,
C. Klein-Bösing
142,
S. Klewin
102,
A. Kluge
36,
M.L. Knichel
36,
A.G. Knospe
124,
C. Kobdaj
113,
M. Kofarago
143,
M.K. Köhler
102,
T. Kollegger
104,
N. Kondratyeva
92,
E. Kondratyuk
91,
A. Konevskikh
63,
M. Konyushikhin
141,
O. Kovalenko
85,
V. Kovalenko
138,
M. Kowalski
116,
I. Králik
66,
A. Kravˇcáková
40,
L. Kreis
104,
M. Krivda
66,
108,
F. Krizek
94,
M. Krüger
70,
E. Kryshen
96,
M. Krzewicki
41,
A.M. Kubera
19,
V. Kuˇcera
94,
61,
C. Kuhn
133,
P.G. Kuijer
90,
J. Kumar
49,
L. Kumar
98,
S. Kumar
49,
S. Kundu
86,
P. Kurashvili
85,
A. Kurepin
63,
A.B. Kurepin
63,
A. Kuryakin
106,
S. Kushpil
94,
J. Kvapil
108,
M.J. Kweon
61,
Y. Kwon
145,
S.L. La Pointe
41,
P. La Rocca
30,
Y.S. Lai
80,
I. Lakomov
36,
R. Langoy
122,
K. Lapidus
144,
C. Lara
75,
A. Lardeux
23,
P. Larionov
52,
E. Laudi
36,
R. Lavicka
39,
R. Lea
27,
L. Leardini
102,
S. Lee
145,
F. Lehas
90,
S. Lehner
111,
J. Lehrbach
41,
R.C. Lemmon
93,
I. León Monzón
118,
P. Lévai
143,
X. Li
13,
X.L. Li
7,
J. Lien
122,
R. Lietava
108,
B. Lim
20,
S. Lindal
23,
V. Lindenstruth
41,
S.W. Lindsay
126,
C. Lippmann
104,
M.A. Lisa
19,
V. Litichevskyi
45,
A. Liu
80,
H.M. Ljunggren
81,
W.J. Llope
141,
D.F. Lodato
64,
V. Loginov
92,
C. Loizides
95,
80,
P. Loncar
37,
X. Lopez
131,
E. López Torres
9,
A. Lowe
143,
P. Luettig
70,
J.R. Luhder
142,
M. Lunardon
31,
G. Luparello
60,
M. Lupi
36,
A. Maevskaya
63,
M. Mager
36,
S.M. Mahmood
23,
A. Maire
133,
R.D. Majka
144,
M. Malaev
96,
Q.W. Malik
23,
L. Malinina
76,
iii,
D. Mal’Kevich
65,
P. Malzacher
104,
A. Mamonov
106,
V. Manko
88,
F. Manso
131,
V. Manzari
53,
Y. Mao
7,
M. Marchisone
128,
74,
132,
J. Mareš
68,
G.V. Margagliotti
27,
ALICE Collaboration / Physics Letters B 785 (2018) 419–428 425
