6533b839fe1ef96bd12a6d5d

RESEARCH PRODUCT

Direct photon production in Pb–Pb collisions atsNN=2.76 TeV

J. AdamD. AdamováM.m. AggarwalG. Aglieri RinellaM. AgnelloN. AgrawalZ. AhammedS.u. AhnS. AiolaA. AkindinovS.n. AlamD. AleksandrovB. AlessandroD. AlexandreR. Alfaro MolinaA. AliciA. AlkinJ.r.m. AlmarazJ. AlmeT. AltS. AltinpinarI. AltsybeevC. Alves Garcia PradoC. AndreiA. AndronicV. AnguelovJ. AnielskiT. AntičićF. AntinoriP. AntonioliL. AphecetcheH. AppelshäuserS. ArcelliR. ArnaldiO.w. ArnoldI.c. ArseneM. ArslandokB. AudurierA. AugustinusR. AverbeckT.c. AwesM.d. AzmiA. BadalàY.w. BaekS. BagnascoR. BailhacheR. BalaA. BaldisseriR.c. BaralA.m. BarbanoR. BarberaF. BarileG.g. BarnaföldiL.s. BarnbyV. BarretP. BartaliniK. BarthJ. BartkeE. BartschM. BasileN. BastidS. BasuB. BathenG. BatigneA. Batista CamejoB. BatyunyaP.c. BatzingI.g. BeardenH. BeckC. BeddaN.k. BeheraI. BelikovF. BelliniH. Bello MartinezR. BellwiedR. BelmontE. Belmont-morenoV. BelyaevG. BencediS. BeoleI. BerceanuA. BercuciY. BerdnikovD. BerenyiR.a. BertensD. BerzanoL. BetevA. BhasinI.r. BhatA.k. BhatiB. BhattacharjeeJ. BhomL. BianchiN. BianchiC. BianchinJ. BielčíkJ. BielčíkováA. BilandzicR. BiswasS. BiswasS. BjelogrlicJ.t. BlairD. BlauC. BlumeF. BockA. BogdanovH. BøggildL. BoldizsárM. BombaraJ. BookH. BorelA. BorissovM. BorriF. BossúE. BottaS. BöttgerC. BourjauP. Braun-munzingerM. BregantT. BreitnerT.a. BrokerT.a. BrowningM. BrozE.j. BruckenE. BrunaG.e. BrunoD. BudnikovH. BueschingS. BufalinoP. BuncicO. BuschZ. ButheleziJ.b. ButtJ.t. BuxtonD. CaffarriX. CaiH. CainesL. Calero DiazA. CalivaE. Calvo VillarP. CameriniF. CarenaW. CarenaF. CarnesecchiJ. Castillo CastellanosA.j. CastroE.a.r. CasulaC. Ceballos SanchezJ. CepilaP. CerelloJ. CerkalaB. ChangS. ChapelandM. ChartierJ.l. CharvetS. ChattopadhyayS. ChattopadhyayV. ChelnokovM. CherneyC. CheshkovB. CheynisV. Chibante BarrosoD.d. ChinellatoS. ChoP. ChochulaK. ChoiM. ChojnackiS. ChoudhuryP. ChristakoglouC.h. ChristensenP. ChristiansenT. ChujoS.u. ChungC. CicaloL. CifarelliF. CindoloJ. CleymansF. ColamariaD. ColellaA. ColluM. ColocciG. Conesa BalbastreZ. Conesa Del ValleM.e. ConnorsJ.g. ContrerasT.m. CormierY. Corrales MoralesI. Cortés MaldonadoP. CorteseM.r. CosentinoF. CostaP. CrochetR. Cruz AlbinoE. CuautleL. CunqueiroT. DahmsA. DaineseA. DanuD. DasI. DasS. DasA. DashS. DashS. DeA. De CaroG. De CataldoC. De ContiJ. De CuvelandA. De FalcoD. De GruttolaN. De MarcoS. De PasqualeA. DeistingA. DeloffE. DénesC. DeplanoP. DhankherD. Di BariA. Di MauroP. Di NezzaM.a. Diaz CorcheroT. DietelP. DillensegerR. DiviàØ. DjuvslandA. DobrinD. Domenicis GimenezB. DönigusO. DordicT. DrozhzhovaA.k. DubeyA. DublaL. DucrouxP. DupieuxR.j. EhlersD. EliaH. EngelE. EppleB. ErazmusI. ErdemirF. ErhardtB. EspagnonM. EstienneS. EsumiJ. EumD. EvansS. EvdokimovG. EyyubovaL. FabbiettiD. FabrisJ. FaivreA. FantoniM. FaselL. FeldkampA. FelicielloG. FeofilovJ. FerenceiA. Fernández TéllezE.g. FerreiroA. FerrettiA. FestantiV.j.g. FeuillardJ. FigielM.a.s. FigueredoS. FilchaginD. FinogeevF.m. FiondaE.m. FioreM.g. FleckM. FlorisS. FoertschP. FokaS. FokinE. FragiacomoA. FrancesconU. FrankenfeldU. FuchsC. FurgetA. FursM. Fusco GirardJ.j. GaardhøjeM. GagliardiA.m. GagoM. GallioD.r. GangadharanP. GanotiC. GaoC. GarabatosE. Garcia-solisC. GargiuloP. GasikE.f. GaugerM. GermainA. GheataM. GheataP. GhoshS.k. GhoshP. GianottiP. GiubellinoP. GiubilatoE. Gladysz-dziadusP. GlässelD.m. Goméz CoralA. Gomez RamirezV. GonzalezP. González-zamoraS. GorbunovL. GörlichS. GotovacV. GrabskiO.a. GrachovL.k. GraczykowskiK.l. GrahamA. GrelliA. GrigorasC. GrigorasV. GrigorievA. GrigoryanS. GrigoryanB. GrinyovN. GrionJ.m. GronefeldJ.f. Grosse-oetringhausJ.-y. GrossiordR. GrossoF. GuberR. GuernaneB. GuerzoniK. GulbrandsenT. GunjiA. GuptaR. GuptaR. HaakeØ. HaalandC. HadjidakisM. HaiducH. HamagakiG. HamarJ.w. HarrisA. HartonD. HatzifotiadouS. HayashiS.t. HeckelM. HeideH. HelstrupA. HerghelegiuG. Herrera CorralB.a. HessK.f. HetlandH. HillemannsB. HippolyteR. HosokawaP. HristovM. HuangT.j. HumanicN. HussainT. HussainD. HutterD.s. HwangR. IlkaevM. InabaM. IppolitovM. IrfanM. IvanovV. IvanovV. IzucheevP.m. JacobsM.b. JadhavS. JadlovskaJ. JadlovskyC. JahnkeM.j. JakubowskaH.j. JangM.a. JanikP.h.s.y. JayarathnaC. JenaS. JenaR.t. Jimenez BustamanteP.g. JonesH. JungA. JuskoP. KalinakA. KalweitJ. KaminJ.h. KangV. KaplinS. KarA. Karasu UysalO. KaravichevT. KaravichevaL. KarayanE. KarpechevU. KebschullR. KeidelD.l.d. KeijdenerM. KeilM. Mohisin KhanP. KhanS.a. KhanA. KhanzadeevY. KharlovB. KilengD.w. KimD.j. KimD. KimH. KimJ.s. KimM. KimM. KimS. KimT. KimS. KirschI. KiselS. KiselevA. KisielG. KissJ.l. KlayC. KleinJ. KleinC. Klein-bösingS. KlewinA. KlugeM.l. KnichelA.g. KnospeT. KobayashiC. KobdajM. KofaragoT. KolleggerA. KolojvariV. KondratievN. KondratyevaE. KondratyukA. KonevskikhM. KopcikM. KourC. KouzinopoulosO. KovalenkoV. KovalenkoM. KowalskiG. Koyithatta MeethaleveeduI. KrálikA. KravčákováM. KretzM. KrivdaF. KrizekE. KryshenM. KrzewickiA.m. KuberaV. KučeraC. KuhnP.g. KuijerA. KumarJ. KumarL. KumarS. KumarP. KurashviliA. KurepinA.b. KurepinA. KuryakinM.j. KweonY. KwonS.l. La PointeP. La RoccaP. Ladron De GuevaraC. Lagana FernandesI. LakomovR. LangoyC. LaraA. LardeuxA. LattucaE. LaudiR. LeaL. LeardiniG.r. LeeS. LeeF. LehasR.c. LemmonV. LentiE. LeograndeI. León MonzónH. León VargasM. LeoncinoP. LévaiS. LiX. LiJ. LienR. LietavaS. LindalV. LindenstruthC. LippmannM.a. LisaH.m. LjunggrenD.f. LodatoP.i. LoenneV. LoginovC. LoizidesX. LopezE. López TorresA. LoweP. LuettigM. LunardonG. LuparelloA. MaevskayaM. MagerS. MahajanS.m. MahmoodA. MaireR.d. MajkaM. MalaevI. Maldonado CervantesL. MalininaD. Mal'kevichP. MalzacherA. MamonovV. MankoF. MansoV. ManzariM. MarchisoneJ. MarešG.v. MargagliottiA. MargottiJ. MarguttiA. MarínC. MarkertM. MarquardN.a. MartinJ. Martin BlancoP. MartinengoM.i. MartínezG. Martínez GarcíaM. Martinez PedreiraA. MasS. MasciocchiM. MaseraA. MasoniL. MassacrierA. MastroserioA. MatyjaC. MayerJ. MazerM.a. MazzoniD. McdonaldF. MeddiY. MelikyanA. Menchaca-rochaE. MeninnoJ. Mercado PérezM. MeresY. MiakeM.m. MieskolainenK. MikhaylovL. MilanoJ. MilosevicL.m. MinerviniA. MischkeA.n. MishraD. MiśkowiecJ. MitraC.m. MituN. MohammadiB. MohantyL. MolnarL. Montaño ZetinaE. MontesD.a. Moreira De GodoyL.a.p. MorenoS. MorettoA. MorrealeA. MorschV. MucciforaE. MudnicD. MühlheimS. MuhuriM. MukherjeeJ.d. MulliganM.g. MunhozR.h. MunzerS. MurrayL. MusaJ. MusinskyB. NaikR. NairB.k. NandiR. NaniaE. NappiM.u. NaruH. Natal Da LuzC. NattrassK. NayakT.k. NayakS. NazarenkoA. NedosekinL. NellenF. NgM. NicassioM. NiculescuJ. NiedzielaB.s. NielsenS. NikolaevS. NikulinV. NikulinF. NoferiniP. NomokonovG. NoorenJ.c.c. NorisJ. NormanA. NyaninJ. NystrandH. OeschlerS. OhS.k. OhA. OhlsonA. OkatanT. OkuboL. OlahJ. OleniaczA.c. Oliveira Da SilvaM.h. OliverJ. OnderwaaterC. OppedisanoR. OravaA. Ortiz VelasquezA. OskarssonJ. OtwinowskiK. OyamaM. OzdemirY. PachmayerP. PaganoG. PaićS.k. PalJ. PanA.k. PandeyP. PapcunV. PapikyanG.s. PappalardoP. PareekW.j. ParkS. ParmarA. PassfeldV. PaticchioR.n. PatraB. PaulT. PeitzmannH. Pereira Da CostaE. Pereira De Oliveira FilhoD. PeresunkoC.e. Pérez LaraE. Perez LezamaV. PeskovY. PestovV. PetráčekV. PetrovM. PetroviciC. PettaS. PianoM. PiknaP. PillotO. PinazzaL. PinskyD.b. PiyarathnaM. PłoskońM. PlaninicJ. PlutaS. PochybovaP.l.m. Podesta-lermaM.g. PoghosyanB. PolichtchoukN. PoljakW. PoonsawatA. PopS. Porteboeuf-houssaisJ. PorterJ. PospisilS.k. PrasadR. PreghenellaF. PrinoC.a. PruneauI. PshenichnovM. PuccioG. PudduP. PujahariV. PuninJ. PutschkeH. QvigstadA. RachevskiS. RahaS. RajputJ. RakA. RakotozafindrabeL. RamelloF. RamiR. RaniwalaS. RaniwalaS.s. RäsänenB.t. RascanuD. RatheeK.f. ReadK. RedlichR.j. ReedA. RehmanP. ReicheltF. ReidtX. RenR. RenfordtA.r. ReolonA. ReshetinJ.-p. RevolK. ReygersV. RiabovR.a. RicciT. RichertM. RichterP. RiedlerW. RieglerF. RiggiC. RisteaE. RoccoM. Rodríguez CahuantziA. Rodriguez MansoK. RøedE. RogochayaD. RohrD. RöhrichR. RomitaF. RonchettiL. RonfletteP. RosnetA. RossiF. RoukoutakisA. RoyC. RoyP. RoyA. J. Rubio Montero10R. RuiR. RussoE. RyabinkinY. RyabovA. RybickiS. SadovskyK. ŠAfaříkB. SahlmullerP. SahooR. SahooS. SahooP.k. SahuJ. SainiS. SakaiM.a. SalehJ. SalzwedelS. SambyalV. SamsonovL. ŠáNdorA. SandovalM. SanoD. SarkarE. ScapparoneF. ScarlassaraC. SchiauaR. SchickerC. SchmidtH.r. SchmidtS. SchuchmannJ. SchukraftM. SchulcT. SchusterY. SchutzK. SchwarzK. SchwedaG. ScioliE. ScomparinR. ScottM. ŠEfčíkJ.e. SegerY. SekiguchiD. SekihataI. SelyuzhenkovK. SenosiS. SenyukovE. SerradillaA. SevcencoA. ShabanovA. ShabetaiO. ShaduraR. ShahoyanA. ShangaraevA. SharmaM. SharmaM. SharmaN. SharmaK. ShigakiK. ShtejerY. SibiriakS. SiddhantaK.m. SielewiczT. SiemiarczukD. SilvermyrC. SilvestreG. SimatovicG. SimonettiR. SingarajuR. SinghS. SinghaV. SinghalB.c. SinhaT. SinhaB. SitarM. SittaT.b. SkaaliM. SlupeckiN. SmirnovR.j.m. SnellingsT.w. SnellmanC. SøgaardJ. SongM. SongZ. SongF. SoramelS. SorensenF. SozziM. SpacekE. SpiritiI. SputowskaM. Spyropoulou-stassinakiJ. StachelI. StanG. StefanekE. StenlundG. SteynJ.h. StillerD. StoccoP. StrmenA.a.p. SuaideT. SugitateC. SuireM. SuleymanovM. SuljicR. SultanovM. ŠUmberaA. SzaboA. Szanto De ToledoI. SzarkaA. SzczepankiewiczM. SzymanskiU. TabassamJ. TakahashiG.j. TambaveN. TanakaM.a. TangaroM. TarhiniM. TariqM.g. TarzilaA. TauroG. Tejeda MuñozA. TelescaK. TerasakiC. TerrevoliB. TeyssierJ. ThäderD. ThomasR. TieulentA.r. TimminsA. ToiaS. TrogoloG. TrombettaV. TrubnikovW.h. TrzaskaT. TsujiA. TumkinR. TurrisiT.s. TveterK. UllalandA. UrasG.l. UsaiA. UtrobicicM. VajzerM. ValaL. Valencia PalomoS. ValleroJ. Van Der MaarelJ.w. Van HoorneM. Van LeeuwenT. VanatP. Vande VyvreD. VargaA. VargasM. VargyasR. VarmaM. VasileiouA. VasilievA. VauthierV. VecherninA.m. VeenM. VeldhoenA. VelureM. VenaruzzoE. VercellinS. Vergara LimónR. VernetM. VerweijL. VickovicG. ViestiJ. ViinikainenZ. VilakaziO. Villalobos BaillieA. Villatoro TelloA. VinogradovL. VinogradovY. VinogradovT. VirgiliV. VislaviciusY.p. ViyogiA. VodopyanovM.a. VölklK. VoloshinS.a. VoloshinG. VolpeB. Von HallerI. VorobyevD. VranicJ. VrlákováB. VulpescuA. VyushinB. WagnerJ. WagnerH. WangM. WangD. WatanabeY. WatanabeM. WeberS.g. WeberD.f. WeiserJ.p. WesselsU. WesterhoffA.m. WhiteheadJ. WiechulaJ. WikneM. WildeG. WilkJ. WilkinsonM.c.s. WilliamsB. WindelbandM. WinnC.g. YaldoH. YangP. YangS. YanoC. YasarZ. YinH. YokoyamaI.-k. YooJ.h. YoonV. YurchenkoI. YushmanovA. ZaborowskaV. ZaccoloA. ZamanC. ZampolliH.j.c. ZanoliS. ZaporozhetsN. ZardoshtiA. ZarochentsevP. ZávadaN. ZaviyalovH. ZbroszczykI.s. ZguraM. ZhalovH. ZhangX. ZhangY. ZhangC. ZhangZ. ZhangC. ZhaoN. ZhigarevaD. ZhouY. ZhouZ. ZhouH. ZhuJ. ZhuA. ZichichiA. ZimmermannM.b. ZimmermannG. ZinovjevM. Zyzak

subject

Quantum chromodynamicsPhysicsNuclear and High Energy PhysicsParticle physicsPhoton010308 nuclear & particles physicsHadronBremsstrahlungPerturbative QCD01 natural sciencesParticle identificationNuclear physics0103 physical sciencesRapidityNuclear Experiment010306 general physicsGlauber

description

Direct photon production at mid-rapidity in Pb–Pb collisions at √sNN = 2.76 TeV was studied in the transverse momentum range 0.9<pT<14 GeV/c. Photons were detected with the highly segmented electromagnetic calorimeter PHOS and via conversions in the ALICE detector material with the e+e− pair reconstructed in the central tracking system. The results of the two methods were combined and direct photon spectra were measured for the 0–20%, 20–40%, and 40–80% centrality classes. For all three classes, agreement was found with perturbative QCD calculations for pT≳5 GeV/c. Direct photon spectra down to pT≈1 GeV/c could be extracted for the 20–40% and 0–20% centrality classes. The significance of the direct photon signal for 0.9<pT<2.1 GeV/c is 2.6σ for the 0–20% class. The spectrum in this pT range and centrality class can be described by an exponential with an inverse slope parameter of (297±12stat±41syst) MeV. State-of-the-art models for photon production in heavy-ion collisions agree with the data within uncertainties.

https://doi.org/10.1016/j.physletb.2016.01.020