J/ ψ elliptic and triangular flow in Pb-Pb collisions at s NN − − − √ = 5.02 TeV
EEUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH
CERN-EP-2020-09428 May 2020c (cid:13) J/ ψ elliptic and triangular flow in Pb–Pb collisions at √ s NN = . TeV
ALICE Collaboration ∗ Abstract
The inclusive J/ ψ elliptic ( v ) and triangular ( v ) flow coefficients measured at forward rapidity (2.5 < y <
4) and the v measured at midrapidity ( | y | < √ s NN = .
02 TeVusing the ALICE detector at the LHC are reported. The entire Pb–Pb data sample collected duringRun 2 is employed, amounting to an integrated luminosity of 750 µ b − at forward rapidity and 93 µ b − at midrapidity. The results are obtained using the scalar product method and are reported asa function of transverse momentum p T and collision centrality. At midrapidity, the J/ ψ v is inagreement with the forward rapidity measurement. The centrality averaged results indicate a positiveJ/ ψ v with a significance of more than 5 σ at forward rapidity in the p T range 2 < p T < c .The forward rapidity v , v , and v / v results at low and intermediate p T ( p T (cid:46) c ) exhibit amass hierarchy when compared to pions and D mesons, while converging into a species-independentcurve at higher p T . At low and intermediate p T , the results could be interpreted in terms of a laterthermalization of charm quarks compared to light quarks, while at high p T , path-length dependenteffects seem to dominate. The J/ ψ v measurements are further compared to a microscopic transportmodel calculation. Using a simplified extension of the quark scaling approach involving both lightand charm quark flow components, it is shown that the D-meson v n measurements can be describedbased on those for charged pions and J/ ψ flow. ∗ See Appendix A for the list of collaboration members a r X i v : . [ nu c l - e x ] M a y / ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration
Ultra-relativistic heavy-ion collisions are the means to create under laboratory conditions the decon-fined state of strongly-interacting matter called quark–gluon plasma (QGP). This state behaves like anideal fluid with a shear viscosity to entropy ratio approaching the conjectured lowest possible value of (cid:125) / ( π k B ) [1–3]. One of the most important observables for studying the properties of the QGP is theazimuthal dependence of particle production, also called anisotropic flow, quantified in terms of a Fourierexpansion with respect to the azimuthal angle of the initial state symmetry plane for the n -th harmonic Ψ n as d N d ϕ ∝ + + ∞ ∑ n = v n cos [ n ( ϕ − Ψ n )] , (1)where v n is the n -th order harmonic coefficient and ϕ is the azimuthal angle of the particles. The initialstate spatial anisotropy of the collision overlap region is transformed into a momentum anisotropy of theproduced final state particles [4–7]. The medium response to the initial state anisotropy ( ε n ), which istransformed into the v n coefficients, strongly depends on the macroscopic properties of the fireball, likethe temperature dependent equation of state and the shear and bulk viscosity.The dominant source of anisotropy is the ellipsoidal shape of the overlap region in non-central collisionsthat have a non-zero finite impact parameter (transverse distance separating the centers of the two nuclei),which gives rise to a large second order harmonic coefficient, v , also known as elliptic flow. Fluctuationsin the initial energy-density profile within the overlap region are thought to be the origin of the triangularflow, v [8–10]. Higher order harmonics are strongly damped, do not depend linearly on the initialanisotropy, and have significant contributions from the interplay of lower order harmonics [11–15]. TheALICE Collaboration published extensive studies of anisotropic flow measurements for identified lightand strange particles [16, 17]. Flow coefficients for all particles show, in the low p T range, an increasingtrend with p T mainly attributed to the radial hydrodynamic expansion of the QGP, reach a maximum inthe p T range 3–5 GeV/ c depending on the particle mass and species, and finally drop towards higher p T .The behavior in the high p T region is commonly attributed to path-length dependent effects like energyloss [18–20]. At both RHIC and LHC energies, an approximate scaling of the flow coefficients withthe number of valence quarks is observed for light and strange particles [16, 17, 21–23]. In the low tomoderate p T range (approximately 3 < p T < c ), this scaling is hypothesized to be the consequenceof the hadronization process via quark coalescence and of a common underlying partonic flow during thehydrodynamic stage of the collision [24–28].The production of charmonia, and especially of J/ ψ , is one of the first proposed probes of the QGPproperties, in particular the deconfinement [29]. Since charm quarks are produced during the early hardpartonic collisions, they experience the entire evolution of the fireball. At the same time, their initialproduction cross section can be calculated in perturbative quantum chromodynamics (QCD). The sup-pression of the production of bound charmonium states by the free color charges of the dense deconfinedmedium is sensitive to both the medium bulk characteristics [30, 31] and to the microscopic ones, like thecharm-quark diffusion coefficient [32, 33]. Measurements of the J/ ψ nuclear modification factor R AA atRHIC in Au–Au collisions at √ s NN =
200 GeV [34] indicated a strong nuclear suppression especially forthe most central collisions. At the LHC, in Pb–Pb collisions at √ s NN = .
76 and 5.02 TeV, the ALICECollaboration reported a much larger R AA compared to the one observed at RHIC [35–37], despite thehigher energy density present in the system. This effect is concentrated in the low- p T region, which isconsistent with charmonium regeneration by recombination of charm quarks, either at the QGP phaseboundary via statistical hadronization [38] or continuously throughout the fireball evolution [39–41].Within the statistical hadronization scenario, charm quarks thermalize in the QGP and all of the charmedbound hadrons are created at the phase boundary assuming chemical equilibration [38, 42], except asmall fraction created in the fireball corona that escape the medium. In transport model approaches,where charm quarks reach only a partial thermalization, roughly 50% of the produced J/ ψ originate2/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaborationfrom the recombination process, while the rest comes from primordial production [39–41]. In bothphenomenological approaches, it is expected that charm quarks will inherit some of the medium radialand anisotropic flow. Indeed, a significant D-meson [43–45] and J/ ψ elliptic flow [46–49] was alreadyobserved at the LHC, indicating a hierarchy between the flow of charged particles, D and J/ ψ mesons,with the J/ ψ flow being the smallest. A positive J/ ψ v observed also at high p T , typically underestimatedby transport model calculations, might suggest the presence of important path length dependent effectslike energy loss and the survival probability in the medium [50, 51]. In addition to v , the ALICECollaboration also published in Ref. [48] an evidence of a positive J/ ψ v with a statistical significanceof 3.7 σ .In this paper, the measurements of inclusive J/ ψ v and v at forward rapidity (2.5 < y <
4) and v atmidrapidity ( | y | < √ s NN = .
02 TeV are discussed. Inclusive J/ ψ mesonsinclude both a prompt component from direct J/ ψ production and decays of excited charmonium statesand a non-prompt component from weak decays of beauty hadrons. The results are presented as afunction of p T in several collision centrality classes, expressed in percentages of the total hadronic crosssection, and are compared with calculations from a microscopic transport model. The analyzed datainclude the full LHC Run 2 Pb–Pb data set, which improves the statistical precision with respect to theprevious results by approximately a factor of two at forward rapidity [48], and a factor of nine(four) incentral(semi-central) collisions at midrapidity [47] allowing the experimental evidence of a statisticallysignificant non-zero J/ ψ v at midrapidity. A detailed description of the ALICE apparatus and its performance can be found in Refs. [52, 53]. Atforward rapidity, J/ ψ are reconstructed in the µ + µ − decay channel with the muon spectrometer whichcovers the pseudorapidity range − < η < − .
5. The spectrometer includes five tracking stations, eachcomposed of two planes of cathode pad chambers. The third station is placed inside a dipole magnetwith a 3 Tm field integral. Two trigger stations, containing two planes of resistive plate chambers each,provide single and dimuon triggers with a programmable single-muon p T threshold. A front absorber,made of carbon, concrete, and steel, is placed in between the primary interaction point (IP) and thefirst tracking station to remove primary hadrons from the collision. A second absorber, made of iron, isplaced in front of the trigger chambers to further reject secondary hadrons escaping the front absorberand low- p T muons, mainly from pion and kaon decays. An additional conical absorber surrounds thebeam pipe to protect the muon spectrometer against secondary particles produced by the interaction oflarge- η particles with the beam pipe.At midrapidity, J/ ψ mesons are reconstructed in the e + e − decay channel using the Inner Tracking Sys-tem (ITS) [54] and the Time Projection Chamber (TPC) [55] in the rapidity range | y | < .
9. The ITSis a cylindrical-shaped detector, consisting of 6 layers of silicon detectors used for precision tracking,reconstruction of the primary vertex of the event and event selection. The innermost two layers consistsof pixels (SPD), the middle two are drift (SDD), while the two outermost layers are equipped with stripdetectors (SSD). The tracklets, track segments reconstructed as pairs of hits in the SPD layers pointing tothe primary vertex, are used for the determination of the event flow vector. The TPC is the main detectorused for tracking and particle identification and consists of a cylindrical-shaped gas-filled active volumeplaced around the ITS. Radially, it extends between an inner radius of 0.85 m and an outer radius of 2.5m, with a total length of 5 m along the beam axis. Particle identification in the TPC is performed via themeasurement of the specific energy loss, d E / d x .Besides the muon spectrometer and the central barrel detectors, a set of detectors for global event char-acterization are also used. Two arrays of 32 scintillator counters each, covering 2 . < η < . − . < η < − . ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaborationthe determination of the collision centrality. The 32 channels are arranged in four concentric rings withfull azimuthal coverage allowing for the calculation of the event flow vector. The centrality of the events,expressed in fractions of the total inelastic hadronic cross section, is determined via a Glauber fit to theV0 amplitude as described in Refs. [57, 58]. In addition, two neutron Zero Degree Calorimeters [59],installed at ± . √ s NN = .
02 TeV using different trigger strategies for the forward muon spectrometer and the midra-pidity detectors.At forward rapidity, data were collected requiring the coincidence of the minimum bias (MB) and unlike-sign dimuon triggers. The former is defined by the coincidence of signals in the V0A and V0C arrayswhile the latter requires at least a pair of opposite-sign track segments in the muon trigger stations. Theprogrammable threshold of the muon trigger algorithm was set so that the trigger efficiency for muontracks with p T = c is 50% and reaches a plateau value of about 98% at p T ≈ c . Inorder to study the background, additional samples of single muon and like-sign dimuon events were alsocollected by requiring, in addition to the MB condition and the low p T threshold, at least one or a pair ofsame-sign track segments in the trigger system, respectively.At midrapidity, data were collected using the MB trigger during the 2015 data taking period, and theMB, central, and semi-central triggers in the 2018 period. The central and semi-central triggers requirethe MB trigger to be fired but, in addition, a condition on the total signal amplitude in the V0 detectors,corresponding to collision centralities of 0–10% and 30–50%, respectively, was applied.Both forward and midrapidity analyses require to have a primary vertex position within ±
10 cm fromthe nominal IP along the beam axis. Events containing more than one collision (pile-up) are removedby exploiting the correlations between the number of clusters in the SPD, the number of reconstructedSPD tracklets, and the total signal in the V0A and V0C detectors. At midrapidity, events with pile-upoccurring during the drift time of the TPC are rejected in the offline analysis based on the correlationbetween the number of SDD and SSD clusters and the total number of clusters in the TPC. The beam-induced background is filtered out offline by applying a selection based on the V0 and the ZDC timinginformation [60].The integrated luminosity of the analyzed data samples is about 750 µ b − for the dimuon analysis. Forthe measurements at midrapidity, the total luminosity recorded depends on the centrality range due tothe centrality triggers, and amounts to 93 µ b − , 41 µ b − , and 20 µ b − for the central, semi-central, andMB triggers, respectively. The v n coefficients are obtained using the scalar product (SP) method [2, 61]. This is a two-particlecorrelation technique based on the scalar product between the unit flow vector for a given harmonic n , u n = e in ϕ , of the particle of interest (here a dilepton) and the complex conjugate of the event flow vectorin a subdetector A, Q A ∗ n . The flow coefficients are thus defined as v n { SP } = (cid:42) u n Q A ∗ n (cid:44)(cid:115) (cid:104) Q An Q B ∗ n (cid:105)(cid:104) Q An Q C ∗ n (cid:105)(cid:104) Q Bn Q C ∗ n (cid:105) (cid:43) (cid:96)(cid:96) , (2)where Q Bn and Q Cn are the n -th harmonic event flow vectors measured in two additional subdetectors, Band C, respectively, which are used to correct the event flow vector via the three sub-event technique [62].The star ( ∗ ) represents the complex conjugate and the bracket (cid:104) ... (cid:105) (cid:96)(cid:96) indicates the average over dileptons4/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaborationfrom all events in a given p T range, dilepton invariant mass ( m (cid:96)(cid:96) ), and centrality interval. The brackets (cid:104) ... (cid:105) in the denominator denote the average over all events in a narrow centrality interval containing theevent under consideration. The V0A and V0C detectors are used in the analysis at both rapidities, whilethe analysis at forward rapidity uses the SPD as the third subdetector, and the analysis at midrapidityuses the TPC. As detector A, the SPD is chosen for the forward analysis and the V0C for the midrapidityone. The V0A and V0C event flow vectors are calculated using the energy deposition measured in theindividual channels. For the SPD and TPC event flow vectors, the reconstructed tracklets and the tracksare used, respectively. Table 1:
Summary of the details concerning the dimuon and dielectron analyses, corresponding to the forward andmidrapidity region, respectively. The detectors cited in this table are described in Sec. 2, and the details concerningthe three sub-event technique is presented in Sec. 3.
Dilepton analysis Three sub-event technique, detectors used Corresponding gap betweenJ/ ψ → l + l − A B C u n and Q An µ + µ − . < y µµ < | ∆ η | > + e − | y ee | < . | ∆ η | > ∆ η between the sub-events used for flow vector determination and dilepton reconstruction. Thepseudorapidity gap between u n and Q An , corresponding to | ∆ η | > . | ∆ η | > . ψ candidates are formed by combining pairs of opposite-sign tracks recon-structed in the geometrical acceptance of the muon spectrometer using the tracking algorithm describedin Ref. [64]. The same single-muon and dimuon selection criteria used in previous analyses [48, 65] areapplied. Namely, each muon track candidate should have − < η µ < − .
5, a radial transverse positionat the end of the front absorber in the range 17 . < R abs < . c p T threshold. The rapidity of the muon pair should bewithin the acceptance of the muon spectrometer (2 . < y < . ψ mesons are reconstructed in the dielectron decay channel. Electron candidates arerequired to be good quality tracks matched in both the ITS and the TPC, and to have a p T > c and | η | < .
9. Tracks are selected to have at least 70 space points in the TPC, out of a maximum of 159,and a χ / N dof < E /d x , by selecting aband of ± σ around the expectation value, with σ being the d E /d x measurement resolution. To reducefurther the hadronic contamination, candidate tracks compatible within ± . σ with the pion or protonhypothesis are rejected.The flow coefficients are extracted from sequential fits to the dilepton invariant mass distribution, m (cid:96)(cid:96) , andthe v n as a function of m (cid:96)(cid:96) , which include the superposition of a J/ ψ signal and a background contribution,using the function v n ( m (cid:96)(cid:96) ) = α ( m (cid:96)(cid:96) ) v J / ψ n + [ − α ( m (cid:96)(cid:96) )] v bkgn ( m (cid:96)(cid:96) ) . (3)Here, v J / ψ n denotes the J/ ψ v or v and α ( m (cid:96)(cid:96) ) is the signal fraction defined as S / ( S + B ) . The latter is5/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaborationextracted from fits to the dilepton invariant mass distribution as described below. The v bkgn ( m (cid:96)(cid:96) ) corre-sponds to the dilepton background v or v . In the dimuon analysis, the J/ ψ signal is parameterized usingan extended Crystal Ball (CB2) function and the background with a Variable Width Gaussian (VWG)function [66]. In the fit, the J/ ψ peak position and width are left free, while the CB2 tail parameters arefixed to the values reported in Ref. [67]. The signal of the ψ ( S ) is not included in the fit of the v n coeffi-cients due to its marginal significance. At midrapidity, the signal fraction is obtained from the dielectroninvariant mass distribution in two steps. First, the combinatorial background is estimated using an event c (GeV/ mm m c C oun t s / M e V / = 5.02 TeV NN s Pb - ALICE Pb 50% - (a1) c (GeV/ mm m - | > . } h D { SP , | v < 4.0 y (a2) c < 3 GeV/ T p c (GeV/ mm m c C oun t s / M e V / - (c1) ) c (GeV/ mm m - | > . } h D { SP , | v < 4.0 y c < 5 GeV/ T p (c2) c (GeV/ ee m c C oun t s / M e V / - (b1) c (GeV/ ee m c C oun t s / M e V / ) c (GeV/ ee m - | > . } h D { SP , | v (b2) | < 0.9 y | c < 4 GeV/ T p Opposite-sign pairsSame-eventMixed-eventMixed-event background subtracted Residual backgroundTotal after mixed-eventbackground substraction SignalBackgroundTotal
Figure 1: (Color online) Invariant mass distribution (top panels a1 , b1 ) and v ( m (cid:96)(cid:96) ) (bottom panels a2 , b2 ) fordimuons in the ranges 2 < p T < c (top left) and for dielectrons in 0 < p T < c (top right), for the30–50% centrality interval. Fit functions of the invariant mass distributions and v ( m µµ ) , as discussed in Sec. 3,are also shown. Bottom panel, invariant mass ( c1 ) and v ( m µµ ) ( c2 ) distributions for dimuons in the p T range2 < p T < c for the 0–50% centrality interval. The v n ( m µµ ) and v ( m ee ) distributions are plotted with thebackground flow obtained from the event-mixing procedure and the fit function, as discussed in the text. Onlystatistical uncertainties are shown. ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaborationmixing technique, where pairs are built from different events with similar collision centrality, flow-vectororientation, and longitudinal position of the event vertex, and then subtracted from the same-event di-electron invariant mass distribution. The combinatorial background normalization is obtained from theratio of the number of same-event to mixed-event like-sign pairs. Second, the remaining distribution isfitted using a component for the signal and one for the residual background. For the J/ ψ signal shape,the dielectron invariant mass distribution obtained from Monte Carlo simulations is used. The residualbackground, originating mainly from semileptonic decays of cc and bb pairs (correlated background)and imperfect matching between the same-event and mixed-event distributions, is parameterized usingeither a third order polynomial function at low p T or an exponential function at high p T .The v n extraction method employed in this work is the same as the one described in detail in Ref. [48],where the v bkgn ( m (cid:96)(cid:96) ) distribution is obtained using an event mixing technique. There, it was first demon-strated that the flow coefficients of the background can be obtained from the flow coefficients of thesingle leptons used to form the background dileptons as v bkgn ( m (cid:96)(cid:96) ) = (cid:104) v ( ) n cos [ n ( ϕ ( ) − ϕ )] + v ( ) n cos [ n ( ϕ ( ) − ϕ )] (cid:105) m (cid:96)(cid:96) (cid:104) + ∞ ∑ m = v ( ) m v ( ) m cos [ m ( ϕ ( ) − ϕ ( ) ] (cid:105) m (cid:96)(cid:96) , (4)where v ( ) n ( ϕ ( ) ) and v ( ) n ( ϕ ( ) ) are the flow coefficients (azimuthal angles) of the two leptons, respec-tively, and ϕ is the dilepton azimuthal angle. The brackets (cid:104)· · · (cid:105) m (cid:96)(cid:96) denote an average over all dileptonsbelonging to the given m (cid:96)(cid:96) interval. Here, it is worth to note that the denominator in Eq. 4 representsthe modification of the dilepton yields induced by the flow of single leptons. Then, when backgrounddileptons are built using the event mixing technique, the numerator in Eq. 4 is given by (cid:68) (cid:104) u n ( ) Q n ( ) , A ∗ (cid:105) R ( ) n cos [ n ( ϕ ( ) − ϕ )] + (cid:104) u n ( ) Q n ( ) , A ∗ (cid:105) R ( ) n cos [ n ( ϕ ( ) − ϕ )] (cid:69) m (cid:96)(cid:96) . (5)Here, u ( ) n and u ( ) n are the unit vector of the two leptons, Q ( ) , An and Q ( ) , An are the event flow vectors,reconstructed in detector A, of the events containing the two leptons, and R ( ) n and R ( ) n their respectiveevent flow factors (corresponding to the denominator of Eq. 2). Since the event flow vectors of the mixedevents are not correlated, the mixed-event dilepton yield is not modified by the flow of the single leptons.Examples of fits to the invariant mass distribution (top panels corresponding to a1 , b1 , c1 ) and to v n ( m (cid:96)(cid:96) ) (bottom panels related to a2 for v ( m µµ ), b2 for v ( m ee ), and c2 for v ( m µµ )) are shown in Fig. 1 for thedimuon and dielectron analyses. The background, which is mostly combinatorial, especially in centralevents, is well reproduced with the event mixing technique. In the absence of correlated background,the background flow v bkgn is directly given by the mixed-event flow. At forward rapidity, the effect ofthe unknown flow contribution of the correlated background and residual mismatches between the same-event and mixed-event background flow, is considered as a systematic uncertainty and is discussed inSec. 4. In the default approach, the flow of the correlated background is assumed to be negligible, andthus the denominator of Eq. 4 is given by the ratio N bkg + − / N mix + − between the number of background unlike-sign dileptons N bkg + − and the number of unlike-sign dileptons from mixed events N mix + − , which is obtainedafter a proper normalization involving like-sign dileptons as described in Ref. [48]. At midrapidity, dueto the smaller signal-to-background ratio, the difference between mixed and same event background flowis taken into account by considering in the fit function an additional term which accounts for the flow ofthe correlated background and imperfections of the mixed event procedure. This term is parameterizedusing a second order polynomial and acts as a correction to the background flow obtained from the mixedevent procedure. 7/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration
The systematic uncertainties related to the v n extraction procedure, the track and event selection criteria,residual detector effects, and non-flow contributions are evaluated as described below and summarizedin Tab.2. A quadratic sum of the systematic uncertainties from the independent sources is used as finalsystematic uncertainty on the measurements.In the dimuon analysis, the signal fraction α ( m µµ ) is estimated by fitting the invariant mass distributionwith standard signal and background functions. The systematic uncertainty on the determination of α ( m µµ ) is estimated by varying the signal and background functions, as well as the mass fit range. Forthe signal, in addition to a CB2, a pseudo-Gaussian with a mass-dependent width [66] is also used. Thetail parameters were fixed to the values obtained in Monte Carlo simulations or in other analyses withbetter signal significance [37, 67]. For the background, the VWG function was changed to a fourthorder Chebyshev polynomial. The invariant mass fit range is varied from the standard 2 − c to2 . − . c in steps of 200 MeV/ c . The corresponding systematic uncertainty for each p T bin,evaluated as the RMS of the results of the various tests, does not exceed 0.003 for v and 0.002 for v . Inthe dielectron analysis, the fit ranges of the residual background fit are varied. No significant changes ofthe extracted elliptic flow are observed and no uncertainty due to the J/ ψ signal extraction is assigned.The non-uniformity in the detector acceptance could lead to a residual effect in the calibration of the eventflow vector Q n . The cross-term products of the event flow vector, (cid:104) Q x , A × Q y , B (cid:105) , are evaluated to verifythat values are negligible compared to the linear products. In addition, possible impacts on the v n arechecked by calculating the cross-term products between the components of the Q n vector and the unitaryvector u n of the J/ ψ candidates. No clear p T or centrality dependence is found for this contribution,and the corresponding systematic uncertainty is estimated to be less than 1%. Additional uncertaintiesrelated to the calculation of the reference flow vector are evaluated as the difference between the eventflow factor R n obtained using MB events or dimuon-triggered events. For the dimuon analysis it amountsto 1% for R and up to 3% for R .The variation of the J/ ψ reconstruction efficiency with the local occupancy of the detector could biasthe measured v n . At forward rapidity, this effect is evaluated using azimuthally isotropic simulatedJ/ ψ → µ + µ − decays embedded into real Pb–Pb events. A maximum effect of 0.002 for v and 0.001for v is observed in non-central collisions with no clear p T dependence. At midrapidity, the strongestdependence of reconstruction performance on the local detector occupancy is caused by the TPC particleidentification (PID). A data driven study, using a clean electron sample from photon conversions, showsthat the largest variation of the TPC electron PID response between the region along the event flow vectorand the region orthogonal to it is approximately 2% of the d E /d x resolution. This leads to a decrease ofthe observed v by less than 1% and is thus neglected.The presence of a correlated background and its unknown flow contribution can affect the v n extraction.The contribution of the correlated background to the flow of the background can be introduced in Eq. 4 byreplacing the denominator N bkg + − / N mix + − by N bkg + − / ( N mix + − + β ( N bkg + − − N mix + − )) , where β represents the relativestrength of the correlated background flow with respect to the combinatorial background flow. Thesystematic uncertainty is defined as the difference between the default fit, equivalent to β =
0, and themodified fit with β left as a free parameter. This uncertainty is, as expected, negligible for centralcollisions and low p T but becomes significant for peripheral collisions and high- p T . The estimatedsystematic uncertainty for the v and v extraction reaches a maximum of about 0.01 for peripheralcollisions and at high- p T .In the dielectron analysis, the signal-to-background ratio can vary significantly depending on the TPCelectron identification selection and centrality, which may impact the J/ ψ v fits. Thus the v was ex-tracted for a set of nine electron PID cuts where both the electron selection and the hadron rejection werevaried such that the J/ ψ efficiency is changed by approximately 50%. The RMS of the v obtained from8/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration
Table 2:
Summary of absolute and relative (in % of v n ) systematic uncertainties of the J/ ψ v and v coefficients,for the dimuon and dielectron analyses. The uncertainties vary within the indicated ranges depending on the p T bin, or centrality interval. µ + µ − e + e − Sources v ( p T ) v ( p T ) v (Centrality) v (Centrality) v ( p T )Extraction method 0–0.003 0–0.002 0.001–0.004 0.001–0.006 neglCentrality- R n determination 1% 3% 2% 3% neglNon-flow estimation <
1% negl <
1% neglReconstruction efficiency 0.001–0.002 0–0.001 0–0.002 0–0.001 neglCorrelated background shape 0–0.009 0–0.015 0–0.010 0–0.011TPC electron 0.010identification selection to 0.023all of these selections is assigned as a systematic uncertainty, which ranges between 0.010 and 0.023depending on the centrality and p T interval, while the average value is taken as central value. In addition,the fit range of the v ( m ee ) is varied by either making it narrower or wider, but no significant systematiceffects are observed. The J/ ψ elliptic flow coefficient measured by ALICE in Pb–Pb collisions at √ s NN = .
02 TeV at forwardand central rapidity is shown in Fig. 2 as a function of p T , for the centrality intervals 0–10%, 10–30%,30–50% and 0–50%. Systematic uncertainties, obtained as described in the previous section, are shownas boxes around the data points, while the statistical uncertainties are shown as error bars. Here, and inall figures as a function of p T , the J/ ψ data points are located at the average p T of the reconstructed J/ ψ .These results are compared with the midrapidity v measurements for charged pions by ALICE [17] andprompt D mesons by ALICE [68] and CMS [43]. At forward rapidity and for all centrality intervals,the J/ ψ v values increase with p T , possibly reaching a maximum at intermediate values of p T , anddecreasing or saturating towards high p T . Also, the J/ ψ v values increase when decreasing centralityfrom the 0–10% to 10–30%, then to 30–50%. This behavior is qualitatively similar to the one for lighthadrons and D mesons. The J/ ψ v measurement at midrapidity is statistically compatible to the one atforward rapidity in both centrality intervals within uncertainties. Considering all the midrapidity datapoints as statistically independent measurements, it was found that the J/ ψ v is larger than zero with asignificance of approximately 2.5 standard deviations in both centrality intervals.As also noted previously [48], a clear mass hierarchy of the v values is seen in the low- p T region( p T < c ) for the light hadrons and D mesons measured at midrapidity and inclusive J/ ψ , with theJ/ ψ exhibiting the lowest elliptic flow. Here, it is important to note that in the considered η range, the η dependence of the v at a given p T is expected to be negligible, as shown by the CMS measurementfor charged particles [69], albeit in a somewhat narrower η range. At high- p T ( p T > c ), the v coefficients from all species converge into a single curve suggesting that, in this kinematic range,the anisotropy for all particles arises dominantly from path-length dependent energy-loss effects [70].However, in the case of the much heavier J/ ψ , one may also consider that the hydrodynamic flow, whicharises from a common velocity field, still contributes significantly even at high p T , as can be expectedfrom the particle mass dependence of the p T range where the flow reaches its maximum.In Fig. 3, the p T -dependent inclusive J/ ψ triangular flow coefficient measured at forward rapidity isshown in each of the considered centrality intervals. For most of the centrality and p T intervals, themeasured inclusive J/ ψ v is positive and with no significant centrality dependence. In the 0–50% cen-trality range, the triangular flow coefficient is larger than zero (0.0250 ± ± ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration ) c (GeV/ T p - v ALICE 10% - y Inclusive J/ < 4 y y |Syst. uncertainty (uncorrelated)2 4 6 8 10 12 14 16 ) c (GeV/ T p - v |<0.8 y average, | *+ , D + , D Prompt DSyst. uncertainty from dataSyst. uncertainty feed-down - ) c (GeV/ T p - v = 5.02 TeV NN s Pb - Pb 30% - |<0.5 y , | – p ) c (GeV/ T p - v - |<1, CMS y , | Prompt DSyst. uncertainty non-prompt
Figure 2: (Color online) Inclusive J/ ψ v as function of p T in different centrality intervals (0–10%, 10–30%,30–50% and 0–50%) in Pb–Pb collisions at √ s NN = .
02 TeV. Both midrapidity and forward rapidity J/ ψ v measurements are shown. The results are compared with the v coefficients at midrapidity for charged pions [17]and prompt D mesons [43, 68]. The statistical and systematic uncertainties are shown as bars and boxes, re-spectively. The shaded cyan boxes represent the systematic uncertainties from the contribution of non-prompt D mesons. < p T < c ) corresponding to a significance of 5.1 σ , calculated adding quadratically the statisticaland systematic uncertainties. The positive v indicates that the initial state energy-density fluctuations,the dominant source of v , are reflected also in the anisotropic flow of charm quarks. Also shown inFig. 3 are similar measurements for charged pions [17] and D mesons [43, 68] obtained at midrapidity.The mass hierarchy observed for v holds also in the case of v . Together with the J/ ψ v , these obser-vations provide a strong support for the hypothesis of charm quark being, at least partially, kineticallyequilibrated in the dense and deconfined QGP medium.The ratio of the triangular to elliptic flow coefficients, v / v , as a function of p T is shown in the leftpanel of Fig. 4 for the inclusive J/ ψ at forward rapidity, D mesons and charged pions at midrapidity.In this ratio, the statistical uncertainties are considered to be uncorrelated due to the weak correlationbetween the orientation of the Q and Q flow vectors [71], while the systematic uncertainties related to α ( m µµ ) and to the reconstruction efficiency discussed in Sec. 4, cancel in the ratio. The same hierarchyobserved for the individual v and v measurements is also observed in the v / v ratio, which suggeststhat higher harmonics are damped faster for heavy quarks than for the light ones. At RHIC [72, 73]and LHC [74, 75], it was observed that the flow coefficients of light particles from different harmonicsfollow a power-law scaling as v / nn ∝ v / mm up to about 6 GeV/ c , for most centrality ranges, but the 0–5%,independently of the harmonics n and m. The ratio v / v / in the right panel of Fig. 4 illustrates such a10/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration ) c (GeV/ T p - v < 4 y , 2.5 < y Inclusive J/Syst. uncertainty (uncorrelated)
ALICE 10% - ) c (GeV/ T p - v |<0.8 y average, | *+ , D + , D Prompt DSyst. uncertainty from dataSyst. uncertainty feed-down - ) c (GeV/ T p - v |<0.5 y , | – p = 5.02 TeV NN s Pb - Pb 30% - ) c (GeV/ T p - v - |<1, CMS y , | Prompt DSyst. uncertainty non-prompt
Figure 3: (Color online) Inclusive J/ ψ v at forward rapidity as function of p T in different centrality intervals(0–10%, 10–30%, 30–50% and 0–50%) in Pb–Pb collisions at √ s NN = .
02 TeV. The results are compared to the v coefficients at midrapidity for charged pions [17] and prompt D mesons [43, 68]. The statistical and systematicuncertainties are shown as bars and boxes, respectively. The shaded bands represent the systematic uncertaintiesfrom the contribution of non-prompt D mesons. scaling. Furthermore, the v / v / for pions, D and J/ ψ mesons tend to converge, although the J/ ψ valuesare systematically lower than the ones of pions.In Fig. 5, the inclusive J/ ψ v as a function of p T in the 20–40% centrality interval is compared withthe microscopic transport calculations by Du et al. [39–41]. In this model, the J/ ψ are created bothfrom the primordial hard partonic interactions but also from the recombination of thermalized charmquarks in the medium, which accounts for roughly 50% of all J/ ψ at low p T . Non-prompt J/ ψ mesons,created in the weak decays of beauty hadrons, are also included in the model. The amplitude of theinclusive J/ ψ v in the calculations is in good agreement with the experimental measurements for p T < c . However, the overall trend of the model calculation does not describe the data well, especiallyin the intermediate p T range, 4 < p T <
10 GeV/ c , where the J/ ψ flow is largely underestimated. Theprimordial J/ ψ component, which is sensitive mainly to path length dependent effects, like survivalprobability, exhibits a monotonically increasing trend from low towards high p T , with this mechanismbecoming the dominant source of the anisotropic flow for p T larger than 8 GeV/ c . Path length dependentenergy loss, widely seen as a major source of anisotropy at large p T , is not implemented for J/ ψ mesonsin this calculation. It is worth noting that this model provides a qualitative good description of thecentrality and transverse momentum of the J/ ψ nuclear modification factor [37, 76].Figure 6 shows the centrality dependence of the inclusive J/ ψ v (top panels) and v (bottom panels)for a low- p T interval (0 < p T < c ) on the left, and a high- p T one (5 < p T <
20 GeV/ c ) on the11/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration ) c (GeV/ T p v / v - ALICE 0 = 5.02 TeV NN s Pb - Pb < 4 y , 2.5 < y Inclusive J/|<0.5 y , | – p Syst. uncertainty (uncorrelated) ) c (GeV/ T p / v / v |<1, CMS y , | Prompt DSyst. uncertainty non-prompt
Figure 4: (Color online) Ratio of v to v of inclusive J/ ψ (left panel) and v / v / (right panel) at forward rapidityas a function of p T for the 0–50% centrality interval in Pb–Pb collisions at √ s NN = .
02 TeV. The resultsare compared with the flow coefficients of charged pions [17] and prompt D mesons at midrapidity [43]. Thestatistical and systematic uncertainties are shown as bars and boxes. The shaded bands represent the systematicuncertainties from the contribution of non-prompt D mesons. right. Here, due to the large integrated p T range, the v n coefficients are corrected for the J/ ψ acceptanceand efficiency A × ε . Each dimuon pair is weighted using the inverse of the p T and y dependent A × ε factor before filling the invariant mass and v n ( m µµ ) distributions. The J/ ψ results are compared with theflow coefficients of charged pions for a p T value similar to the corrected J/ ψ (cid:104) p T (cid:105) , published by ALICEin Ref. [17]. In addition, the ratio v π / v J / ψ is computed and shown in the bottom sub-panels. Both atlow p T (1 . < p T < c ) and high p T (6 < p T < c ), the v of π ± increases from central tosemi-central collisions, reaching a maximum at 40–50% centrality, and then decreases towards periph-eral collisions. For the J/ ψ at low p T , while the centrality trend is qualitatively similar, the maximum (oreven saturation) of v seems to be reached for more central collisions than for the pions. This is moreclearly emphasized by the increasing trend of the ratio v π / v J / ψ , from central to peripheral collisions,which deviates from unity by a significance of 8.5 σ . In the framework of transport models, this could beunderstood by the increasing fraction of regenerated J/ ψ at low p T when moving from peripheral to cen-tral collisions. Alternatively, and independently of the regeneration scenario, the increase of the v π / v J / ψ from central to peripheral collisions, could also be understood in terms of partial or later thermalizationof the charm quarks compared to light quarks. The decrease in energy density and lifetime of the systemis counterbalanced by the increase of the initial spatial anisotropy towards peripheral collisions. The v of the J/ ψ will therefore reach its maximum at more central collisions compared to light particles becausecharm quarks require larger energy densities to develop flow [33, 77–79]. At high p T , J/ ψ mesons andcharged pions seem to exhibit the same centrality dependence, although the v coefficients are systemat-ically lower for the J/ ψ mesons than for the pions. Such a similar centrality dependence could indicate asimilar mechanism at the origin of the flow for both J/ ψ mesons and pions at high p T .The centrality dependence of the v coefficient at low p T is less pronounced than that of the v for bothpions and J/ ψ , as expected since initial state fluctuations only weakly depend on centrality. Also, the J/ ψ v is smaller relative to the one of charged pions, in both the p T intervals considered.The flow of light and strange particles was shown to approximately scale with the number of constituentquarks (NCQ scaling) at both RHIC and LHC energies [80, 81]. This was typically interpreted to arise12/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration ) c (GeV/ T p - v = 5.02 TeV NN s Pb -
40% Pb - ALICE 20 < 4 y , 2.5 < y Inclusive J/| > 1.1} hD {SP, | v Syst. (uncorrelated)TAMU (X. Du et al.) y Inclusive J/ y Primordial J/
Figure 5: (Color online) Inclusive J/ ψ v as function of p T at forward rapidity for semi-central (20â ˘A ¸S40%)Pbâ ˘A ¸SPb collisions at √ s NN = .
02 TeV. Calculations from a transport model [39, 40] are also shown. naturally in hadronization scenarios based on quark coalescence in which the flow of bound mesons andbaryons depends solely on the collective flow of light and strange quarks (assumed to be identical) andthe number of valence quarks [24, 28]. In the case of charmed hadrons, the NCQ scaling assuming aflavor independent flow would obviously not work due to the large observed differences between the flowof light-flavor particles, D and J/ ψ mesons. However, one can extend this scaling by assuming that themuch heavier charm quark has a different flow magnitude [25] and that it can be derived from the flowof the J/ ψ via the usual NCQ formula, v J / ψ n ( p J / ψ T ) = · v cn ( p J / ψ T / ) . Then it is straightforward to showthat the flow of the D meson can be constructed as the sum of the flow coefficients for light and charmquarks as v Dn ( p DT ) = v qn ( p qT ) + v cn ( p cT ) , (6)where p qT and p cT are the p T of the light and charm quarks, respectively, corresponding to the D-meson p T , p DT . The light quark flow is obtained by interpolating the measured charged pions flow using v π n ( p π T ) = · v qn ( p π T / ) . Figure 7 shows a comparison of the D-meson v and v as a function of p T , derived assumingthe above described procedure, to the measured D-meson v n [43].The red dashed curves show fits to the J/ ψ v n employing an ad-hoc function, a third order polynomial atlow- p T and a linear function at high- p T , used to extract the flow of charm quarks needed to obtain thescaled D-meson flow according to Eq. 6. The scaled D-meson flow is found to be very sensitive to thefraction of p T carried by each of the constituent quarks. In coalescence-like models, constituent quarksmust have equal velocities which leads to a sharing of the D-meson p T proportional to the effective quarkmasses. This implies that by far the largest fraction of p T should be carried by the charm quark. Based onthe simplistic and naive approach described here, a p T sharing between light and charm quarks [25, 82]where the ratio p qT / p DT = . p T (dark blue and greencurves). The best agreement with the D-meson CMS data is obtained when the light-quark p T fractionhas a value of p qT / p DT = 0.4 (dark blue curve), but a rather good description of the data is observed alsowhen assuming that the light and charm quarks share equally the D-meson p T (green curve). Within13/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration
10 20 30 40 50 60 70 80
Centrality (%) v ALICE
10 20 30 40 50 60 70 80
Centrality (%) y J / v / –p v
10 20 30 40 50 60 70 80
Centrality (%) v y Inclusive J/ c < 5 GeV/ T p c > 5 GeV/ T p | > 1.1} hD {SP, | n v < 4, y y , T p ( e · A (weighted candidate pairs)
10 20 30 40 50 60 70 80
Centrality (%) v = 5.02 TeV NN s Pb - Pb
10 20 30 40 50 60 70 80
Centrality (%) y J / v / –p v
10 20 30 40 50 60 70 80
Centrality (%) v – p c < 2 GeV/ T p c < 7 GeV/ T p hD {2, | n v |<0.5, y | Figure 6:
The inclusive J/ ψ v and v as function of the centrality of the collision, at forward rapidity, for thelow- p T range 0 < p T < c (left panel) and high- p T range 5 < p T <
20 GeV/ c (right panel). The results arecompared to the v n coefficients of midrapidity π ± [17] at low and high- p T corresponding to 1 . < p T < c and 6 < p T < c , respectively. The ratio of midrapidity π ± v to inclusive J/ ψ v is also shown. uncertainties, the scaling seems to work well for both v and v over the entire covered p T range and inall centrality intervals. In summary, the inclusive J/ ψ v at forward and midrapidity and the J/ ψ v at forward rapidity weremeasured in Pb–Pb collisions at √ s NN = .
02 TeV using the scalar product method. In non-centralcollisions, the J/ ψ v values are found to be positive up to the last interval corresponding to 12 < p T <
20 GeV/ c and reach a maximum of approximately 0.1 around a p T of 5 GeV/ c . The J/ ψ v values atforward rapidity reach 0.04 around a p T of 4 GeV/ c and are positive in the 0–50% centrality interval for2 < p T < c with a significance of 5.1 σ . The mass hierarchy observed for v , v , π > v , D > v , J / ψ ,14/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration ) c (GeV/ T p - v y Inclusive J/ |<0.5 y , | – p < 4 y y | ALICE 10% - ) c (GeV/ T p - v = 0.5 DT p / qT p = 0.4 DT p / qT p , c Best = 0.2 DT p / qT p - ) c (GeV/ T p - v - ) c (GeV/ T p - v - v cn v + qn v = Dn v Scaled y J/n v Fitted = 5.02 TeV NN s Pb - Pb ) c (GeV/ T p - v - v |<1, CMS y , | Prompt DSyst. uncertainty from dataSyst. uncertainty non-prompt ) c (GeV/ T p - v - v Figure 7: (Color online) Elliptic (left panels) and triangular (right panels) flow of inclusive J/ ψ , D-mesons andcharged pions as a function of p T for the centrality intervals 0–10% (top), 10–30% (middle) and 30–50% (bottom).The continuous curves show the calculated D-meson flow based on different values of the p T fraction carried bythe light quark (see text). The red dashed curves show the fits to the J/ ψ v n using ad-hoc functions (see text). seems to also hold in the case of v and will be the subject of more detailed studies with the Run 3 andRun 4 data. At high p T , the v for all particles converge to similar values, suggesting that path-lengthdependent effects become dominant there. The measured J/ ψ v / v ratios exhibits the same hierarchyindicating that higher harmonics are damped faster for charmonia compared to lighter particles. The p T -integrated v coefficient in a low and a high- p T region is in both cases dependent on centrality andreaches a maximum value of about 0.1, while the v has no clear centrality dependence. Both J/ ψ p T -integrated v and v coefficients, either at low- p T or at high- p T are found to be lower than the ones ofcharged pions at a p T similar to the J/ ψ average p T . At low p T , the ratio of the charged pions v to thoseof p T -integrated J/ ψ increase from central to peripheral collisions, compatible with a scenario in whichcharm quarks thermalize later than the light ones. At high p T , this ratio is compatible with unity withoutany statistically significant centrality dependence.Using an extension of the well known number of constituent quark scaling, the measured charged pion15/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaborationand J/ ψ v n can be used as proxies in order to derive the D-meson v and v as a combination of the flowof light and charm quarks. Within this procedure, it is surprising to observe that the measured D meson v and v can be described if one considers that the light and charm quarks share similar fractions of theD-meson p T , which is counterintuitive in a coalescence approach. The fact that such a simple scalingworks suggests that the flow of charmonia and open charm mesons can be effectively explained assuminga common underlying charm quark flow in addition to the flow of light quarks. Acknowledgements
The ALICE Collaboration would like to thank all its engineers and technicians for their invaluable con-tributions to the construction of the experiment and the CERN accelerator teams for the outstandingperformance of the LHC complex. The ALICE Collaboration gratefully acknowledges the resources andsupport provided by all Grid centres and the Worldwide LHC Computing Grid (WLCG) collaboration.The ALICE Collaboration acknowledges the following funding agencies for their support in buildingand running the ALICE detector: A. I. Alikhanyan National Science Laboratory (Yerevan Physics In-stitute) Foundation (ANSL), State Committee of Science and World Federation of Scientists (WFS),Armenia; Austrian Academy of Sciences, Austrian Science Fund (FWF): [M 2467-N36] and National-stiftung für Forschung, Technologie und Entwicklung, Austria; Ministry of Communications and HighTechnologies, National Nuclear Research Center, Azerbaijan; Conselho Nacional de DesenvolvimentoCientífico e Tecnológico (CNPq), Financiadora de Estudos e Projetos (Finep), Fundação de Amparo àPesquisa do Estado de São Paulo (FAPESP) and Universidade Federal do Rio Grande do Sul (UFRGS),Brazil; Ministry of Education of China (MOEC) , Ministry of Science & Technology of China (MSTC)and National Natural Science Foundation of China (NSFC), China; Ministry of Science and Educationand Croatian Science Foundation, Croatia; Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear(CEADEN), Cubaenergía, Cuba; Ministry of Education, Youth and Sports of the Czech Republic, CzechRepublic; The Danish Council for Independent Research | Natural Sciences, the VILLUM FONDEN andDanish National Research Foundation (DNRF), Denmark; Helsinki Institute of Physics (HIP), Finland;Commissariat à l’Energie Atomique (CEA) and Institut National de Physique Nucléaire et de Physiquedes Particules (IN2P3) and Centre National de la Recherche Scientifique (CNRS), France; Bundesmin-isterium für Bildung und Forschung (BMBF) and GSI Helmholtzzentrum für SchwerionenforschungGmbH, Germany; General Secretariat for Research and Technology, Ministry of Education, Researchand Religions, Greece; National Research, Development and Innovation Office, Hungary; Departmentof Atomic Energy Government of India (DAE), Department of Science and Technology, Governmentof India (DST), University Grants Commission, Government of India (UGC) and Council of Scientificand Industrial Research (CSIR), India; Indonesian Institute of Science, Indonesia; Centro Fermi - MuseoStorico della Fisica e Centro Studi e Ricerche Enrico Fermi and Istituto Nazionale di Fisica Nucleare(INFN), Italy; Institute for Innovative Science and Technology , Nagasaki Institute of Applied Science(IIST), Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) and Japan So-ciety for the Promotion of Science (JSPS) KAKENHI, Japan; Consejo Nacional de Ciencia (CONACYT)y Tecnología, through Fondo de Cooperación Internacional en Ciencia y Tecnología (FONCICYT) andDirección General de Asuntos del Personal Academico (DGAPA), Mexico; Nederlandse Organisatievoor Wetenschappelijk Onderzoek (NWO), Netherlands; The Research Council of Norway, Norway;Commission on Science and Technology for Sustainable Development in the South (COMSATS), Pak-istan; Pontificia Universidad Católica del Perú, Peru; Ministry of Science and Higher Education, NationalScience Centre and WUT ID-UB, Poland; Korea Institute of Science and Technology Information andNational Research Foundation of Korea (NRF), Republic of Korea; Ministry of Education and ScientificResearch, Institute of Atomic Physics and Ministry of Research and Innovation and Institute of AtomicPhysics, Romania; Joint Institute for Nuclear Research (JINR), Ministry of Education and Science ofthe Russian Federation, National Research Centre Kurchatov Institute, Russian Science Foundation andRussian Foundation for Basic Research, Russia; Ministry of Education, Science, Research and Sport of16/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaborationthe Slovak Republic, Slovakia; National Research Foundation of South Africa, South Africa; SwedishResearch Council (VR) and Knut & Alice Wallenberg Foundation (KAW), Sweden; European Organi-zation for Nuclear Research, Switzerland; Suranaree University of Technology (SUT), National Scienceand Technology Development Agency (NSDTA) and Office of the Higher Education Commission underNRU project of Thailand, Thailand; Turkish Atomic Energy Agency (TAEK), Turkey; National Academyof Sciences of Ukraine, Ukraine; Science and Technology Facilities Council (STFC), United Kingdom;National Science Foundation of the United States of America (NSF) and United States Department ofEnergy, Office of Nuclear Physics (DOE NP), United States of America.
References [1] P. Kovtun, D. T. Son, and A. O. Starinets, “Viscosity in strongly interacting quantum field theoriesfrom black hole physics”,
Phys. Rev. Lett. (2005) 111601, arXiv:hep-th/0405231[hep-th] .[2] S. A. Voloshin, A. M. Poskanzer, and R. Snellings, “Collective phenomena in non-central nuclearcollisions”, Landolt-Bornstein (2010) 293–333, arXiv:0809.2949 [nucl-ex] .[3] P. Romatschke, “New Developments in Relativistic Viscous Hydrodynamics”, Int. J. Mod. Phys.
E19 (2010) 1–53, arXiv:0902.3663 [hep-ph] .[4] J.-Y. Ollitrault, “Anisotropy as a signature of transverse collective flow”,
Phys. Rev.
D46 (1992)229–245.[5] S. Voloshin and Y. Zhang, “Flow study in relativistic nuclear collisions by Fourier expansion ofAzimuthal particle distributions”,
Z. Phys.
C70 (1996) 665–672, arXiv:hep-ph/9407282[hep-ph] .[6] Z. Qiu and U. W. Heinz, “Event-by-event shape and flow fluctuations of relativistic heavy-ioncollision fireballs”,
Phys. Rev.
C84 (2011) 024911, arXiv:1104.0650 [nucl-th] .[7] D. A. Teaney, “Viscous Hydrodynamics and the Quark Gluon Plasma”, in
Quark-gluon plasma 4 ,R. C. Hwa and X.-N. Wang, eds., pp. 207–266. QGP4, 2010. arXiv:0905.2433 [nucl-th] .[8] M. Luzum and P. Romatschke, “Conformal Relativistic Viscous Hydrodynamics: Applications toRHIC results at √ s NN = GeV”,
Phys. Rev.
C78 (2008) 034915, arXiv:0804.4015[nucl-th] . [Erratum: Phys. Rev.C79,039903(2009)].[9] B. Alver and G. Roland, “Collision geometry fluctuations and triangular flow in heavy-ioncollisions”,
Phys. Rev.
C81 (2010) 054905, arXiv:1003.0194 [nucl-th] . [Erratum: Phys.Rev.C82,039903(2010)].[10] D. Teaney and L. Yan, “Triangularity and Dipole Asymmetry in Heavy Ion Collisions”,
Phys. Rev.
C83 (2011) 064904, arXiv:1010.1876 [nucl-th] .[11] H. Niemi, G. S. Denicol, H. Holopainen, and P. Huovinen, “Event-by-event distributions ofazimuthal asymmetries in ultrarelativistic heavy-ion collisions”,
Phys. Rev.
C87 no. 5, (2013)054901, arXiv:1212.1008 [nucl-th] .[12] F. G. Gardim, F. Grassi, M. Luzum, and J.-Y. Ollitrault, “Mapping the hydrodynamic response tothe initial geometry in heavy-ion collisions”,
Phys. Rev.
C85 (2012) 024908, arXiv:1111.6538[nucl-th] . 17/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration[13] F. G. Gardim, J. Noronha-Hostler, M. Luzum, and F. Grassi, “Effects of viscosity on the mappingof initial to final state in heavy ion collisions”,
Phys. Rev.
C91 no. 3, (2015) 034902, arXiv:1411.2574 [nucl-th] .[14]
ALICE
Collaboration, S. Acharya et al. , “Linear and non-linear flow modes in Pb-Pb collisions at √ s NN = Phys. Lett. B (2017) 68–80, arXiv:1705.04377 [nucl-ex] .[15]
ALICE
Collaboration, S. Acharya et al. , “Linear and non-linear flow modes of charged hadrons inPb-Pb collisions at √ s NN = 5.02 TeV”, arXiv:2002.00633 [nucl-ex] .[16] ALICE
Collaboration, B. Abelev et al. , “Elliptic flow of identified hadrons in Pb-Pb collisions at √ s NN = .
76 TeV”,
JHEP (2015) 190, arXiv:1405.4632 [nucl-ex] .[17] ALICE
Collaboration, S. Acharya et al. , “Anisotropic flow of identified particles in Pb-Pbcollisions at √ s NN = .
02 TeV”,
JHEP (2018) 006, arXiv:1805.04390 [nucl-ex] .[18] B. Betz, M. Gyulassy, M. Luzum, J. Noronha, J. Noronha-Hostler, I. Portillo, and C. Ratti,“Cumulants and nonlinear response of high p T harmonic flow at √ s NN = .
02 TeV”,
Phys. Rev.
C95 no. 4, (2017) 044901, arXiv:1609.05171 [nucl-th] .[19]
CMS
Collaboration, S. Chatrchyan et al. , “Study of high-pT charged particle suppression in PbPbcompared to pp collisions at √ s NN = .
76 TeV”,
Eur. Phys. J.
C72 (2012) 1945, arXiv:1202.2554 [nucl-ex] .[20] N. Armesto, A. Dainese, C. A. Salgado, and U. A. Wiedemann, “Testing the color charge andmass dependence of parton energy loss with heavy-to-light ratios at RHIC and CERN LHC”,
Phys. Rev.
D71 (2005) 054027, arXiv:hep-ph/0501225 [hep-ph] .[21]
STAR
Collaboration, J. Adams et al. , “Particle type dependence of azimuthal anisotropy andnuclear modification of particle production in Au + Au collisions at √ s NN =
200 GeV”,
Phys. Rev.Lett. (2004) 052302, arXiv:nucl-ex/0306007 [nucl-ex] .[22] PHENIX
Collaboration, S. Afanasiev et al. , “Elliptic flow for phi mesons and (anti)deuterons inAu + Au collisions at √ s NN =
200 GeV”,
Phys. Rev. Lett. (2007) 052301, arXiv:nucl-ex/0703024 [NUCL-EX] .[23] STAR
Collaboration, L. Adamczyk et al. , “Centrality dependence of identified particle ellipticflow in relativistic heavy ion collisions at √ s NN =7.7-62.4 GeV”, Phys. Rev.
C93 no. 1, (2016)014907, arXiv:1509.08397 [nucl-ex] .[24] D. Molnar and S. A. Voloshin, “Elliptic flow at large transverse momenta from quarkcoalescence”,
Phys. Rev. Lett. (2003) 092301, arXiv:nucl-th/0302014 [nucl-th] .[25] Z.-W. Lin and D. Molnar, “Quark coalescence and elliptic flow of charm hadrons”, Phys. Rev.
C68 (2003) 044901, arXiv:nucl-th/0304045 [nucl-th] .[26]
STAR
Collaboration, J. Adams et al. , “Multi-strange baryon elliptic flow in Au + Au collisions at √ s NN =
200 GeV”,
Phys. Rev. Lett. (2005) 122301, arXiv:nucl-ex/0504022 [nucl-ex] .[27] R. J. Fries, V. Greco, and P. Sorensen, “Coalescence Models For Hadron Formation From QuarkGluon Plasma”, Ann. Rev. Nucl. Part. Sci. (2008) 177–205, arXiv:0807.4939 [nucl-th] .[28] STAR
Collaboration, J. Adams et al. , “Azimuthal anisotropy in Au+Au collisions at √ s NN = Phys. Rev.
C72 (2005) 014904, arXiv:nucl-ex/0409033 [nucl-ex] .18/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration[29] T. Matsui and H. Satz, “ J / ψ Suppression by Quark-Gluon Plasma Formation”,
Phys. Lett.
B178 (1986) 416–422.[30] S. Digal, P. Petreczky, and H. Satz, “Quarkonium feed down and sequential suppression”,
Phys.Rev.
D64 (2001) 094015, arXiv:hep-ph/0106017 [hep-ph] .[31] A. Rothkopf, “Heavy Quarkonium in Extreme Conditions”,
Phys. Rept. (2020) 1–117, arXiv:1912.02253 [hep-ph] .[32] F. Riek and R. Rapp, “Quarkonia and Heavy-Quark Relaxation Times in the Quark-GluonPlasma”,
Phys. Rev.
C82 (2010) 035201, arXiv:1005.0769 [hep-ph] .[33] F. Scardina, S. K. Das, V. Minissale, S. Plumari, and V. Greco, “Estimating the charm quarkdiffusion coefficient and thermalization time from D meson spectra at energies available at theBNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider”,
Phys. Rev.
C96 no. 4, (2017) 044905, arXiv:1707.05452 [nucl-th] .[34]
PHENIX
Collaboration, A. Adare et al. , “ J / ψ Production vs Centrality, Transverse Momentum,and Rapidity in Au+Au Collisions at √ s NN =
200 GeV”,
Phys. Rev. Lett. (2007) 232301, arXiv:nucl-ex/0611020 [nucl-ex] .[35] ALICE
Collaboration, B. Abelev et al. , “ J / ψ suppression at forward rapidity in Pb-Pb collisionsat √ s NN = .
76 TeV”,
Phys. Rev. Lett. (2012) 072301, arXiv:1202.1383 [hep-ex] .[36]
ALICE
Collaboration, B. Abelev et al. , “Centrality, rapidity and transverse momentumdependence of J / ψ suppression in Pb-Pb collisions at √ s NN =2.76 TeV”, Phys. Lett.
B734 (2014)314–327, arXiv:1311.0214 [nucl-ex] .[37]
ALICE
Collaboration, J. Adam et al. , “J/ ψ suppression at forward rapidity in Pb-Pb collisions at √ s NN = .
02 TeV”,
Phys. Lett.
B766 (2017) 212–224, arXiv:1606.08197 [nucl-ex] .[38] P. Braun-Munzinger and J. Stachel, “(Non)thermal aspects of charmonium production and a newlook at J/ ψ suppression”, Phys. Lett.
B490 (2000) 196–202, arXiv:nucl-th/0007059[nucl-th] .[39] X. Du and R. Rapp, “Sequential Regeneration of Charmonia in Heavy-Ion Collisions”,
Nucl.Phys.
A943 (2015) 147–158, arXiv:1504.00670 [hep-ph] .[40] X. Du, R. Rapp, and M. He, “Color Screening and Regeneration of Bottomonia in High-EnergyHeavy-Ion Collisions”,
Phys. Rev.
C96 no. 5, (2017) 054901, arXiv:1706.08670 [hep-ph] .[41] K. Zhou, N. Xu, Z. Xu, and P. Zhuang, “Medium effects on charmonium production atultrarelativistic energies available at the CERN Large Hadron Collider”,
Phys. Rev.
C89 no. 5,(2014) 054911, arXiv:1401.5845 [nucl-th] .[42] A. Andronic, P. Braun-Munzinger, M. K. Köhler, K. Redlich, and J. Stachel, “Transversemomentum distributions of charmonium states with the statistical hadronization model”,
Phys.Lett.
B797 (2019) 134836, arXiv:1901.09200 [nucl-th] .[43]
CMS
Collaboration, A. M. Sirunyan et al. , “Measurement of prompt D meson azimuthalanisotropy in Pb-Pb collisions at √ s NN = 5.02 TeV”, Phys. Rev. Lett. no. 20, (2018) 202301, arXiv:1708.03497 [nucl-ex] .[44]
ALICE
Collaboration, S. Acharya et al. , “Event-shape engineering for the D-meson elliptic flowin mid-central Pb-Pb collisions at √ s NN = .
02 TeV”,
JHEP (2019) 150, arXiv:1809.09371[nucl-ex] . 19/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration[45]
ALICE
Collaboration, S. Acharya et al. , “D-meson azimuthal anisotropy in midcentral Pb-Pbcollisions at √ s NN = .
02 TeV”,
Phys. Rev. Lett. no. 10, (2018) 102301, arXiv:1707.01005[nucl-ex] .[46]
CMS
Collaboration, V. Khachatryan et al. , “Suppression and azimuthal anisotropy of prompt andnonprompt J / ψ production in PbPb collisions at √ s NN = .
76 TeV”,
Eur. Phys. J. C no. 4,(2017) 252, arXiv:1610.00613 [nucl-ex] .[47] ALICE
Collaboration, S. Acharya et al. , “J/ ψ elliptic flow in Pb-Pb collisions at √ s NN = . Phys. Rev. Lett. no. 24, (2017) 242301, arXiv:1709.05260 [nucl-ex] .[48]
ALICE
Collaboration, S. Acharya et al. , “Study of J/ ψ azimuthal anisotropy at forward rapidityin Pb-Pb collisions at √ s NN = .
02 TeV”,
JHEP (2019) 012, arXiv:1811.12727 [nucl-ex] .[49] ATLAS
Collaboration, M. Aaboud et al. , “Prompt and non-prompt J / ψ elliptic flow in Pb+Pbcollisions at √ s NN = .
02 Tev with the ATLAS detector”,
Eur. Phys. J. C no. 9, (2018) 784, arXiv:1807.05198 [nucl-ex] .[50] F. Arleo, “Quenching of Hadron Spectra in Heavy Ion Collisions at the LHC”, Phys. Rev. Lett. no. 6, (2017) 062302, arXiv:1703.10852 [hep-ph] .[51] M. Spousta, “On similarity of jet quenching and charmonia suppression”,
Phys. Lett. B (2017)10–15, arXiv:1606.00903 [hep-ph] .[52]
ALICE
Collaboration, K. Aamodt et al. , “The ALICE experiment at the CERN LHC”,
JINST (2008) S08002.[53] ALICE
Collaboration, B. Abelev et al. , “Performance of the ALICE Experiment at the CERNLHC”,
Int. J. Mod. Phys.
A29 (2014) 1430044, arXiv:1402.4476 [nucl-ex] .[54]
ALICE
Collaboration, K. Aamodt et al. , “Alignment of the ALICE Inner Tracking System withcosmic-ray tracks”,
JINST (2010) P03003, arXiv:1001.0502 [physics.ins-det] .[55] J. Alme et al. , “The ALICE TPC, a large 3-dimensional tracking device with fast readout forultra-high multiplicity events”, Nucl. Instrum. Meth.
A622 (2010) 316–367, arXiv:1001.1950[physics.ins-det] .[56]
ALICE
Collaboration, E. Abbas et al. , “Performance of the ALICE VZERO system”,
JINST (2013) P10016, arXiv:1306.3130 [nucl-ex] .[57] ALICE
Collaboration, B. Abelev et al. , “Centrality determination of Pb-Pb collisions at √ s NN =2.76 TeV with ALICE”, Phys. Rev.
C88 no. 4, (2013) 044909, arXiv:1301.4361 [nucl-ex] .[58]
ALICE
Collaboration, “Centrality determination in heavy ion collisions”,
ALICE-PUBLIC-2018-011 (2018) . http://cds.cern.ch/record/2636623 .[59]
ALICE
Collaboration, B. Abelev et al. , “Measurement of the Cross Section for ElectromagneticDissociation with Neutron Emission in Pb-Pb Collisions at √ s NN = .
76 TeV”,
Phys.Rev.Lett. (2012) 252302, arXiv:1203.2436 [nucl-ex] .[60]
ALICE
Collaboration, B. Abelev et al. , “Centrality determination of Pb-Pb collisions at √ s NN =2.76 TeV with ALICE”, Phys. Rev.
C88 no. 4, (2013) 044909, arXiv:1301.4361 [nucl-ex] .[61]
STAR
Collaboration, C. Adler et al. , “Elliptic flow from two and four particle correlations inAu+Au collisions at √ s NN = 130 GeV”, Phys. Rev.
C66 (2002) 034904, arXiv:nucl-ex/0206001 [nucl-ex] . 20/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration[62] M. Luzum and J.-Y. Ollitrault, “Eliminating experimental bias in anisotropic-flow measurementsof high-energy nuclear collisions”,
Phys. Rev. C no. 4, (2013) 044907, arXiv:1209.2323[nucl-ex] .[63] I. Selyuzhenkov and S. Voloshin, “Effects of non-uniform acceptance in anisotropic flowmeasurement”, Phys. Rev.
C77 (2008) 034904, arXiv:0707.4672 [nucl-th] .[64]
ALICE
Collaboration, K. Aamodt et al. , “Rapidity and transverse momentum dependence ofinclusive J / ψ production in pp collisions at √ s = Phys. Lett.
B704 (2011) 442–455, arXiv:1105.0380 [hep-ex] . [Erratum: Phys. Lett.B718,692(2012)].[65]
ALICE
Collaboration, J. Adam et al. , “Differential studies of inclusive J/ ψ and ψ ( S ) productionat forward rapidity in Pb-Pb collisions at √ s NN = .
76 TeV”,
JHEP (2016) 179, arXiv:1506.08804 [nucl-ex] .[66] ALICE
Collaboration, J. Adam et al. , “Quarkonium signal extraction in ALICE”, tech. rep.,CERN, 2015. http://cds.cern.ch/record/2060096 .[67]
ALICE
Collaboration, S. Acharya et al. , “Energy dependence of forward-rapidity J / ψ and ψ ( ) production in pp collisions at the LHC”, Eur. Phys. J.
C77 no. 6, (2017) 392, arXiv:1702.00557[hep-ex] .[68]
ALICE
Collaboration, S. Acharya et al. , “Transverse-momentum and event-shape dependence ofD-meson flow harmonics in Pb-Pb collisions at √ s NN = .
02 TeV”, arXiv:2005.0xxxx[nucl-ex] .[69]
CMS
Collaboration, A. M. Sirunyan et al. , “Pseudorapidity and transverse momentumdependence of flow harmonics in pPb and PbPb collisions”,
Phys. Rev.
C98 no. 4, (2018) 044902, arXiv:1710.07864 [nucl-ex] .[70]
ALICE
Collaboration, B. Abelev et al. , “Anisotropic flow of charged hadrons, pions and(anti-)protons measured at high transverse momentum in Pb-Pb collisions at √ s NN =2.76 TeV”, Phys. Lett.
B719 (2013) 18–28, arXiv:1205.5761 [nucl-ex] .[71]
ATLAS
Collaboration, G. Aad et al. , “Measurement of event-plane correlations in √ s NN = . Phys. Rev.
C90 no. 2, (2014) 024905, arXiv:1403.0489 [hep-ex] .[72]
STAR
Collaboration, J. Adams et al. , “Azimuthal anisotropy at RHIC: The First and fourthharmonics”,
Phys. Rev. Lett. (2004) 062301, arXiv:nucl-ex/0310029 [nucl-ex] .[73] PHENIX
Collaboration, A. Adare et al. , “Elliptic and hexadecapole flow of charged hadrons inAu+Au collisions at √ s NN =
200 GeV”,
Phys. Rev. Lett. (2010) 062301, arXiv:1003.5586[nucl-ex] .[74]
ATLAS
Collaboration, G. Aad et al. , “Measurement of the azimuthal anisotropy for chargedparticle production in √ s NN = .
76 TeV lead-lead collisions with the ATLAS detector”,
Phys. Rev.
C86 (2012) 014907, arXiv:1203.3087 [hep-ex] .[75]
ALICE
Collaboration, S. Acharya et al. , “Energy dependence and fluctuations of anisotropic flowin Pb-Pb collisions at √ s NN = .
02 and 2.76 TeV”,
JHEP (2018) 103, arXiv:1804.02944[nucl-ex] .[76] ALICE
Collaboration, S. Acharya et al. , “Studies of J/ ψ production at forward rapidity in Pb-Pbcollisions at √ s NN = 5.02 TeV”, JHEP (2020) 041, arXiv:1909.03158 [nucl-ex] .21/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration[77] A. Beraudo et al. , “Extraction of Heavy-Flavor Transport Coefficients in QCD Matter”,
Nucl.Phys. A (2018) 21–86, arXiv:1803.03824 [nucl-th] .[78] T. Song, H. Berrehrah, D. Cabrera, J. M. Torres-Rincon, L. Tolos, W. Cassing, andE. Bratkovskaya, “Tomography of the Quark-Gluon-Plasma by Charm Quarks”,
Phys. Rev. C no. 1, (2015) 014910, arXiv:1503.03039 [nucl-th] .[79] S. Cao and S. A. Bass, “Thermalization of charm quarks in infinite and finite QGP matter”, Phys.Rev. C (2011) 064902, arXiv:1108.5101 [nucl-th] .[80] L. Zheng, H. Li, H. Qin, Q.-Y. Shou, and Z.-B. Yin, “Investigating the NCQ scaling of ellipticflow at LHC with a multiphase transport model”, Eur. Phys. J.
A53 no. 6, (2017) 124, arXiv:1611.05185 [nucl-th] .[81] S. Singha and M. Nasim, “Scaling of elliptic flow in heavy-ion collisions with the number ofconstituent quarks in a transport model”,
Phys. Rev.
C93 no. 3, (2016) 034908, arXiv:1603.01220 [nucl-ex] .[82] J. Jia and C. Zhang, “Quark number scaling of v in transverse kinetic energy and its implicationsfor coalescence models”, Phys. Rev.
C75 (2007) 031901, arXiv:hep-ph/0608187 [hep-ph] .22/ ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration
A The ALICE Collaboration
S. Acharya , D. Adamová , A. Adler , J. Adolfsson , M.M. Aggarwal , G. Aglieri Rinella ,M. Agnello , N. Agrawal
10 ,54 , Z. Ahammed , S. Ahmad , S.U. Ahn , Z. Akbar , A. Akindinov ,M. Al-Turany , S.N. Alam
40 ,141 , D.S.D. Albuquerque , D. Aleksandrov , B. Alessandro ,H.M. Alfanda , R. Alfaro Molina , B. Ali , Y. Ali , A. Alici
10 ,26 ,54 , N. Alizadehvandchali ,A. Alkin , J. Alme , T. Alt , L. Altenkamper , I. Altsybeev , M.N. Anaam , C. Andrei ,D. Andreou , A. Andronic , M. Angeletti , V. Anguelov , C. Anson , T. Antiˇci´c , F. Antinori ,P. Antonioli , N. Apadula , L. Aphecetche , H. Appelshäuser , S. Arcelli , R. Arnaldi , M. Arratia ,I.C. Arsene , M. Arslandok , A. Augustinus , R. Averbeck , S. Aziz , M.D. Azmi , A. Badalà ,Y.W. Baek , S. Bagnasco , X. Bai , R. Bailhache , R. Bala , A. Balbino , A. Baldisseri , M. Ball ,S. Balouza , D. Banerjee , R. Barbera , L. Barioglio , G.G. Barnaföldi , L.S. Barnby , V. Barret ,P. Bartalini , C. Bartels , K. Barth , E. Bartsch , F. Baruffaldi , N. Bastid , S. Basu , G. Batigne ,B. Batyunya , D. Bauri , J.L. Bazo Alba , I.G. Bearden , C. Beattie , C. Bedda , N.K. Behera ,I. Belikov , A.D.C. Bell Hechavarria , F. Bellini , R. Bellwied , V. Belyaev , G. Bencedi ,S. Beole , A. Bercuci , Y. Berdnikov , D. Berenyi , R.A. Bertens , D. Berzano , M.G. Besoiu ,L. Betev , A. Bhasin , I.R. Bhat , M.A. Bhat , H. Bhatt , B. Bhattacharjee , A. Bianchi ,L. Bianchi , N. Bianchi , J. Bielˇcík , J. Bielˇcíková , A. Bilandzic , G. Biro , R. Biswas , S. Biswas ,J.T. Blair , D. Blau , C. Blume , G. Boca , F. Bock , A. Bogdanov , S. Boi , J. Bok ,L. Boldizsár , A. Bolozdynya , M. Bombara , G. Bonomi , H. Borel , A. Borissov , H. Bossi ,E. Botta , L. Bratrud , P. Braun-Munzinger , M. Bregant , M. Broz , E. Bruna , G.E. Bruno
33 ,106 ,M.D. Buckland , D. Budnikov , H. Buesching , S. Bufalino , O. Bugnon , P. Buhler , P. Buncic ,Z. Buthelezi
72 ,131 , J.B. Butt , S.A. Bysiak , D. Caffarri , A. Caliva , E. Calvo Villar ,J.M.M. Camacho , R.S. Camacho , P. Camerini , F.D.M. Canedo , A.A. Capon , F. Carnesecchi ,R. Caron , J. Castillo Castellanos , A.J. Castro , E.A.R. Casula , F. Catalano , C. Ceballos Sanchez ,P. Chakraborty , S. Chandra , W. Chang , S. Chapeland , M. Chartier , S. Chattopadhyay ,S. Chattopadhyay , A. Chauvin , C. Cheshkov , B. Cheynis , V. Chibante Barroso ,D.D. Chinellato , S. Cho , P. Chochula , T. Chowdhury , P. Christakoglou , C.H. Christensen ,P. Christiansen , T. Chujo , C. Cicalo , L. Cifarelli
10 ,26 , L.D. Cilladi , F. Cindolo , M.R. Ciupek ,G. Clai
54 ,ii , J. Cleymans , F. Colamaria , D. Colella , A. Collu , M. Colocci , M. Concas
59 ,iii , G. ConesaBalbastre , Z. Conesa del Valle , G. Contin
24 ,60 , J.G. Contreras , T.M. Cormier , Y. Corrales Morales ,P. Cortese , M.R. Cosentino , F. Costa , S. Costanza , P. Crochet , E. Cuautle , P. Cui ,L. Cunqueiro , D. Dabrowski , T. Dahms , A. Dainese , F.P.A. Damas
115 ,137 , M.C. Danisch ,A. Danu , D. Das , I. Das , P. Das , P. Das , S. Das , A. Dash , S. Dash , S. De , A. De Caro ,G. de Cataldo , J. de Cuveland , A. De Falco , D. De Gruttola , N. De Marco , S. De Pasquale ,S. Deb , H.F. Degenhardt , K.R. Deja , A. Deloff , S. Delsanto
25 ,131 , W. Deng , P. Dhankher , D. DiBari , A. Di Mauro , R.A. Diaz , T. Dietel , P. Dillenseger , Y. Ding , R. Divià , D.U. Dixit ,Ø. Djuvsland , U. Dmitrieva , A. Dobrin , B. Dönigus , O. Dordic , A.K. Dubey , A. Dubla
90 ,107 ,S. Dudi , M. Dukhishyam , P. Dupieux , R.J. Ehlers , V.N. Eikeland , D. Elia , B. Erazmus ,F. Erhardt , A. Erokhin , M.R. Ersdal , B. Espagnon , G. Eulisse , D. Evans , S. Evdokimov ,L. Fabbietti , M. Faggin , J. Faivre , F. Fan , A. Fantoni , M. Fasel , P. Fecchio , A. Feliciello ,G. Feofilov , A. Fernández Téllez , A. Ferrero , A. Ferretti , A. Festanti , V.J.G. Feuillard ,J. Figiel , S. Filchagin , D. Finogeev , F.M. Fionda , G. Fiorenza , F. Flor , A.N. Flores ,S. Foertsch , P. Foka , S. Fokin , E. Fragiacomo , U. Frankenfeld , U. Fuchs , C. Furget , A. Furs ,M. Fusco Girard , J.J. Gaardhøje , M. Gagliardi , A.M. Gago , A. Gal , C.D. Galvan , P. Ganoti ,C. Garabatos , J.R.A. Garcia , E. Garcia-Solis , K. Garg , C. Gargiulo , A. Garibli , K. Garner ,P. Gasik
105 ,107 , E.F. Gauger , M.B. Gay Ducati , M. Germain , J. Ghosh , P. Ghosh , S.K. Ghosh ,M. Giacalone , P. Gianotti , P. Giubellino
59 ,107 , P. Giubilato , A.M.C. Glaenzer , P. Glässel , A. GomezRamirez , V. Gonzalez
107 ,143 , L.H. González-Trueba , S. Gorbunov , L. Görlich , A. Goswami ,S. Gotovac , V. Grabski , L.K. Graczykowski , K.L. Graham , L. Greiner , A. Grelli , C. Grigoras ,V. Grigoriev , A. Grigoryan , S. Grigoryan , O.S. Groettvik , F. Grosa
30 ,59 , J.F. Grosse-Oetringhaus ,R. Grosso , R. Guernane , M. Guittiere , K. Gulbrandsen , T. Gunji , A. Gupta , R. Gupta ,I.B. Guzman , R. Haake , M.K. Habib , C. Hadjidakis , H. Hamagaki , G. Hamar , M. Hamid ,R. Hannigan , M.R. Haque
63 ,86 , A. Harlenderova , J.W. Harris , A. Harton , J.A. Hasenbichler ,H. Hassan , Q.U. Hassan , D. Hatzifotiadou
10 ,54 , P. Hauer , L.B. Havener , S. Hayashi ,S.T. Heckel , E. Hellbär , H. Helstrup , A. Herghelegiu , T. Herman , E.G. Hernandez , G. HerreraCorral , F. Herrmann , K.F. Hetland , H. Hillemanns , C. Hills , B. Hippolyte , B. Hohlweger , ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration
J. Honermann , D. Horak , A. Hornung , S. Hornung , R. Hosokawa
15 ,133 , P. Hristov , C. Huang ,C. Hughes , P. Huhn , T.J. Humanic , H. Hushnud , L.A. Husova , N. Hussain , S.A. Hussain ,D. Hutter , J.P. Iddon
34 ,127 , R. Ilkaev , H. Ilyas , M. Inaba , G.M. Innocenti , M. Ippolitov ,A. Isakov , M.S. Islam , M. Ivanov , V. Ivanov , V. Izucheev , B. Jacak , N. Jacazio
34 ,54 ,P.M. Jacobs , S. Jadlovska , J. Jadlovsky , S. Jaelani , C. Jahnke , M.J. Jakubowska ,M.A. Janik , T. Janson , M. Jercic , O. Jevons , M. Jin , F. Jonas
96 ,144 , P.G. Jones , J. Jung ,M. Jung , A. Jusko , P. Kalinak , A. Kalweit , V. Kaplin , S. Kar , A. Karasu Uysal , D. Karatovic ,O. Karavichev , T. Karavicheva , P. Karczmarczyk , E. Karpechev , A. Kazantsev , U. Kebschull ,R. Keidel , M. Keil , B. Ketzer , Z. Khabanova , A.M. Khan , S. Khan , A. Khanzadeev ,Y. Kharlov , A. Khatun , A. Khuntia , B. Kileng , B. Kim , B. Kim , D. Kim , D.J. Kim ,E.J. Kim , H. Kim , J. Kim , J.S. Kim , J. Kim , J. Kim , J. Kim , M. Kim , S. Kim ,T. Kim , T. Kim , S. Kirsch , I. Kisel , S. Kiselev , A. Kisiel , J.L. Klay , C. Klein , J. Klein
34 ,59 ,S. Klein , C. Klein-Bösing , M. Kleiner , T. Klemenz , A. Kluge , M.L. Knichel , A.G. Knospe ,C. Kobdaj , M.K. Köhler , T. Kollegger , A. Kondratyev , N. Kondratyeva , E. Kondratyuk ,J. Konig , S.A. Konigstorfer , P.J. Konopka , G. Kornakov , L. Koska , O. Kovalenko ,V. Kovalenko , M. Kowalski , I. Králik , A. Kravˇcáková , L. Kreis , M. Krivda
64 ,111 , F. Krizek ,K. Krizkova Gajdosova , M. Krüger , E. Kryshen , M. Krzewicki , A.M. Kubera , V. Kuˇcera
34 ,61 ,C. Kuhn , P.G. Kuijer , L. Kumar , S. Kundu , P. Kurashvili , A. Kurepin , A.B. Kurepin ,A. Kuryakin , S. Kushpil , J. Kvapil , M.J. Kweon , J.Y. Kwon , Y. Kwon , S.L. La Pointe , P. LaRocca , Y.S. Lai , M. Lamanna , R. Langoy , K. Lapidus , A. Lardeux , P. Larionov , E. Laudi ,R. Lavicka , T. Lazareva , R. Lea , L. Leardini , J. Lee , S. Lee , S. Lehner , J. Lehrbach ,R.C. Lemmon , I. León Monzón , E.D. Lesser , M. Lettrich , P. Lévai , X. Li , X.L. Li , J. Lien ,R. Lietava , B. Lim , V. Lindenstruth , A. Lindner , C. Lippmann , M.A. Lisa , A. Liu , J. Liu ,S. Liu , W.J. Llope , I.M. Lofnes , V. Loginov , C. Loizides , P. Loncar , J.A. Lopez , X. Lopez ,E. López Torres , J.R. Luhder , M. Lunardon , G. Luparello , Y.G. Ma , A. Maevskaya , M. Mager ,S.M. Mahmood , T. Mahmoud , A. Maire , R.D. Majka
146 ,i , M. Malaev , Q.W. Malik , L. Malinina
75 ,iv ,D. Mal’Kevich , P. Malzacher , G. Mandaglio
32 ,56 , V. Manko , F. Manso , V. Manzari , Y. Mao ,M. Marchisone , J. Mareš , G.V. Margagliotti , A. Margotti , A. Marín , C. Markert ,M. Marquard , C.D. Martin , N.A. Martin , P. Martinengo , J.L. Martinez , M.I. Martínez ,G. Martínez García , S. Masciocchi , M. Masera , A. Masoni , L. Massacrier , E. Masson ,A. Mastroserio
53 ,138 , A.M. Mathis , O. Matonoha , P.F.T. Matuoka , A. Matyja , C. Mayer ,F. Mazzaschi , M. Mazzilli , M.A. Mazzoni , A.F. Mechler , F. Meddi , Y. Melikyan
62 ,93 ,A. Menchaca-Rocha , C. Mengke , E. Meninno
29 ,114 , A.S. Menon , M. Meres , S. Mhlanga ,Y. Miake , L. Micheletti , L.C. Migliorin , D.L. Mihaylov , K. Mikhaylov
75 ,92 , A.N. Mishra ,D. Mi´skowiec , A. Modak , N. Mohammadi , A.P. Mohanty , B. Mohanty , M. Mohisin Khan
16 ,v ,Z. Moravcova , C. Mordasini , D.A. Moreira De Godoy , L.A.P. Moreno , I. Morozov , A. Morsch ,T. Mrnjavac , V. Muccifora , E. Mudnic , D. Mühlheim , S. Muhuri , J.D. Mulligan , A. Mulliri
23 ,55 ,M.G. Munhoz , R.H. Munzer , H. Murakami , S. Murray , L. Musa , J. Musinsky , C.J. Myers ,J.W. Myrcha , B. Naik , R. Nair , B.K. Nandi , R. Nania
10 ,54 , E. Nappi , M.U. Naru ,A.F. Nassirpour , C. Nattrass , R. Nayak , T.K. Nayak , S. Nazarenko , A. Neagu , R.A. Negrao DeOliveira , L. Nellen , S.V. Nesbo , G. Neskovic , D. Nesterov , L.T. Neumann , B.S. Nielsen ,S. Nikolaev , S. Nikulin , V. Nikulin , F. Noferini
10 ,54 , P. Nomokonov , J. Norman
79 ,127 , N. Novitzky ,P. Nowakowski , A. Nyanin , J. Nystrand , M. Ogino , A. Ohlson , J. Oleniacz , A.C. Oliveira DaSilva , M.H. Oliver , C. Oppedisano , A. Ortiz Velasquez , A. Oskarsson , J. Otwinowski ,K. Oyama , Y. Pachmayer , V. Pacik , S. Padhan , D. Pagano , G. Pai´c , J. Pan , S. Panebianco ,P. Pareek
50 ,141 , J. Park , J.E. Parkkila , S. Parmar , S.P. Pathak , B. Paul , J. Pazzini , H. Pei ,T. Peitzmann , X. Peng , L.G. Pereira , H. Pereira Da Costa , D. Peresunko , G.M. Perez , S. Perrin ,Y. Pestov , V. Petráˇcek , M. Petrovici , R.P. Pezzi , S. Piano , M. Pikna , P. Pillot , O. Pinazza
34 ,54 ,L. Pinsky , C. Pinto , S. Pisano
10 ,52 , D. Pistone , M. Płosko´n , M. Planinic , F. Pliquett ,M.G. Poghosyan , B. Polichtchouk , N. Poljak , A. Pop , S. Porteboeuf-Houssais , V. Pozdniakov ,S.K. Prasad , R. Preghenella , F. Prino , C.A. Pruneau , I. Pshenichnov , M. Puccio , J. Putschke ,S. Qiu , L. Quaglia , R.E. Quishpe , S. Ragoni , S. Raha , S. Rajput , J. Rak ,A. Rakotozafindrabe , L. Ramello , F. Rami , S.A.R. Ramirez , R. Raniwala , S. Raniwala ,S.S. Räsänen , R. Rath , V. Ratza , I. Ravasenga , K.F. Read
96 ,130 , A.R. Redelbach , K. Redlich
85 ,vi ,A. Rehman , P. Reichelt , F. Reidt , X. Ren , R. Renfordt , Z. Rescakova , K. Reygers , A. Riabov ,V. Riabov , T. Richert
81 ,89 , M. Richter , P. Riedler , W. Riegler , F. Riggi , C. Ristea , S.P. Rode , ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration
M. Rodríguez Cahuantzi , K. Røed , R. Rogalev , E. Rogochaya , D. Rohr , D. Röhrich , P.F. Rojas ,P.S. Rokita , F. Ronchetti , A. Rosano , E.D. Rosas , K. Roslon , A. Rossi
28 ,57 , A. Rotondi ,A. Roy , P. Roy , O.V. Rueda , R. Rui , B. Rumyantsev , A. Rustamov , E. Ryabinkin , Y. Ryabov ,A. Rybicki , H. Rytkonen , O.A.M. Saarimaki , R. Sadek , S. Sadhu , S. Sadovsky , K. Šafaˇrík ,S.K. Saha , B. Sahoo , P. Sahoo , R. Sahoo , S. Sahoo , P.K. Sahu , J. Saini , S. Sakai ,S. Sambyal , V. Samsonov
93 ,98 , D. Sarkar , N. Sarkar , P. Sarma , V.M. Sarti , M.H.P. Sas ,E. Scapparone , J. Schambach , H.S. Scheid , C. Schiaua , R. Schicker , A. Schmah , C. Schmidt ,H.R. Schmidt , M.O. Schmidt , M. Schmidt , N.V. Schmidt
68 ,96 , A.R. Schmier , J. Schukraft ,Y. Schutz , K. Schwarz , K. Schweda , G. Scioli , E. Scomparin , J.E. Seger , Y. Sekiguchi ,D. Sekihata , I. Selyuzhenkov
93 ,107 , S. Senyukov , D. Serebryakov , A. Sevcenco , A. Shabanov ,A. Shabetai , R. Shahoyan , W. Shaikh , A. Shangaraev , A. Sharma , A. Sharma , H. Sharma ,M. Sharma , N. Sharma , S. Sharma , O. Sheibani , K. Shigaki , M. Shimomura , S. Shirinkin ,Q. Shou , Y. Sibiriak , S. Siddhanta , T. Siemiarczuk , D. Silvermyr , G. Simatovic , G. Simonetti ,B. Singh , R. Singh , R. Singh , R. Singh , V.K. Singh , V. Singhal , T. Sinha , B. Sitar ,M. Sitta , T.B. Skaali , M. Slupecki , N. Smirnov , R.J.M. Snellings , C. Soncco , J. Song ,A. Songmoolnak , F. Soramel , S. Sorensen , I. Sputowska , J. Stachel , I. Stan , P.J. Steffanic ,E. Stenlund , S.F. Stiefelmaier , D. Stocco , M.M. Storetvedt , L.D. Stritto , A.A.P. Suaide ,T. Sugitate , C. Suire , M. Suleymanov , M. Suljic , R. Sultanov , M. Šumbera , V. Sumberia ,S. Sumowidagdo , S. Swain , A. Szabo , I. Szarka , U. Tabassam , S.F. Taghavi , G. Taillepied ,J. Takahashi , G.J. Tambave , S. Tang , M. Tarhini , M.G. Tarzila , A. Tauro , G. Tejeda Muñoz ,A. Telesca , L. Terlizzi , C. Terrevoli , D. Thakur , S. Thakur , D. Thomas , F. Thoresen ,R. Tieulent , A. Tikhonov , A.R. Timmins , A. Toia , N. Topilskaya , M. Toppi , F. Torales-Acosta ,S.R. Torres , A. Trifiró
32 ,56 , S. Tripathy
50 ,69 , T. Tripathy , S. Trogolo , G. Trombetta , L. Tropp ,V. Trubnikov , W.H. Trzaska , T.P. Trzcinski , B.A. Trzeciak
37 ,63 , A. Tumkin , R. Turrisi ,T.S. Tveter , K. Ullaland , E.N. Umaka , A. Uras , G.L. Usai , M. Vala , N. Valle , S. Vallero ,N. van der Kolk , L.V.R. van Doremalen , M. van Leeuwen , P. Vande Vyvre , D. Varga , Z. Varga ,M. Varga-Kofarago , A. Vargas , M. Vasileiou , A. Vasiliev , O. Vázquez Doce , V. Vechernin ,E. Vercellin , S. Vergara Limón , L. Vermunt , R. Vernet , R. Vértesi , L. Vickovic , Z. Vilakazi ,O. Villalobos Baillie , G. Vino , A. Vinogradov , T. Virgili , V. Vislavicius , A. Vodopyanov ,B. Volkel , M.A. Völkl , K. Voloshin , S.A. Voloshin , G. Volpe , B. von Haller , I. Vorobyev ,D. Voscek , J. Vrláková , B. Wagner , M. Weber , S.G. Weber , A. Wegrzynek , S.C. Wenzel ,J.P. Wessels , J. Wiechula , J. Wikne , G. Wilk , J. Wilkinson , G.A. Willems , E. Willsher ,B. Windelband , M. Winn , W.E. Witt , J.R. Wright , Y. Wu , R. Xu , S. Yalcin , Y. Yamaguchi ,K. Yamakawa , S. Yang , S. Yano , Z. Yin , H. Yokoyama , I.-K. Yoo , J.H. Yoon , S. Yuan ,A. Yuncu , V. Yurchenko , V. Zaccolo , A. Zaman , C. Zampolli , H.J.C. Zanoli , N. Zardoshti ,A. Zarochentsev , P. Závada , N. Zaviyalov , H. Zbroszczyk , M. Zhalov , S. Zhang , X. Zhang ,Z. Zhang , V. Zherebchevskii , Y. Zhi , D. Zhou , Y. Zhou , Z. Zhou , J. Zhu , Y. Zhu ,A. Zichichi
10 ,26 , G. Zinovjev , N. Zurlo , Affiliation notes i Deceased ii Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA),Bologna, Italy iii
Dipartimento DET del Politecnico di Torino, Turin, Italy iv M.V. Lomonosov Moscow State University, D.V. Skobeltsyn Institute of Nuclear, Physics, Moscow, Russia v Department of Applied Physics, Aligarh Muslim University, Aligarh, India vi Institute of Theoretical Physics, University of Wroclaw, Poland
Collaboration Institutes A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute) Foundation, Yerevan, Armenia Bogolyubov Institute for Theoretical Physics, National Academy of Sciences of Ukraine, Kiev, Ukraine Bose Institute, Department of Physics and Centre for Astroparticle Physics and Space Science (CAPSS),Kolkata, India Budker Institute for Nuclear Physics, Novosibirsk, Russia California Polytechnic State University, San Luis Obispo, California, United States ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration Central China Normal University, Wuhan, China Centre de Calcul de l’IN2P3, Villeurbanne, Lyon, France Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear (CEADEN), Havana, Cuba Centro de Investigación y de Estudios Avanzados (CINVESTAV), Mexico City and Mérida, Mexico Centro Fermi - Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi’, Rome, Italy Chicago State University, Chicago, Illinois, United States China Institute of Atomic Energy, Beijing, China Comenius University Bratislava, Faculty of Mathematics, Physics and Informatics, Bratislava, Slovakia COMSATS University Islamabad, Islamabad, Pakistan Creighton University, Omaha, Nebraska, United States Department of Physics, Aligarh Muslim University, Aligarh, India Department of Physics, Pusan National University, Pusan, Republic of Korea Department of Physics, Sejong University, Seoul, Republic of Korea Department of Physics, University of California, Berkeley, California, United States Department of Physics, University of Oslo, Oslo, Norway Department of Physics and Technology, University of Bergen, Bergen, Norway Dipartimento di Fisica dell’Università ’La Sapienza’ and Sezione INFN, Rome, Italy Dipartimento di Fisica dell’Università and Sezione INFN, Cagliari, Italy Dipartimento di Fisica dell’Università and Sezione INFN, Trieste, Italy Dipartimento di Fisica dell’Università and Sezione INFN, Turin, Italy Dipartimento di Fisica e Astronomia dell’Università and Sezione INFN, Bologna, Italy Dipartimento di Fisica e Astronomia dell’Università and Sezione INFN, Catania, Italy Dipartimento di Fisica e Astronomia dell’Università and Sezione INFN, Padova, Italy Dipartimento di Fisica ‘E.R. Caianiello’ dell’Università and Gruppo Collegato INFN, Salerno, Italy Dipartimento DISAT del Politecnico and Sezione INFN, Turin, Italy Dipartimento di Scienze e Innovazione Tecnologica dell’Università del Piemonte Orientale and INFNSezione di Torino, Alessandria, Italy Dipartimento di Scienze MIFT, Università di Messina, Messina, Italy Dipartimento Interateneo di Fisica ‘M. Merlin’ and Sezione INFN, Bari, Italy European Organization for Nuclear Research (CERN), Geneva, Switzerland Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Split,Split, Croatia Faculty of Engineering and Science, Western Norway University of Applied Sciences, Bergen, Norway Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Prague,Czech Republic Faculty of Science, P.J. Šafárik University, Košice, Slovakia Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-Universität Frankfurt, Frankfurt,Germany Fudan University, Shanghai, China Gangneung-Wonju National University, Gangneung, Republic of Korea Gauhati University, Department of Physics, Guwahati, India Helmholtz-Institut für Strahlen- und Kernphysik, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn,Germany Helsinki Institute of Physics (HIP), Helsinki, Finland High Energy Physics Group, Universidad Autónoma de Puebla, Puebla, Mexico Hiroshima University, Hiroshima, Japan Hochschule Worms, Zentrum für Technologietransfer und Telekommunikation (ZTT), Worms, Germany Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Romania Indian Institute of Technology Bombay (IIT), Mumbai, India Indian Institute of Technology Indore, Indore, India Indonesian Institute of Sciences, Jakarta, Indonesia INFN, Laboratori Nazionali di Frascati, Frascati, Italy INFN, Sezione di Bari, Bari, Italy INFN, Sezione di Bologna, Bologna, Italy INFN, Sezione di Cagliari, Cagliari, Italy INFN, Sezione di Catania, Catania, Italy ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration INFN, Sezione di Padova, Padova, Italy INFN, Sezione di Roma, Rome, Italy INFN, Sezione di Torino, Turin, Italy INFN, Sezione di Trieste, Trieste, Italy Inha University, Incheon, Republic of Korea Institute for Nuclear Research, Academy of Sciences, Moscow, Russia Institute for Subatomic Physics, Utrecht University/Nikhef, Utrecht, Netherlands Institute of Experimental Physics, Slovak Academy of Sciences, Košice, Slovakia Institute of Physics, Homi Bhabha National Institute, Bhubaneswar, India Institute of Physics of the Czech Academy of Sciences, Prague, Czech Republic Institute of Space Science (ISS), Bucharest, Romania Institut für Kernphysik, Johann Wolfgang Goethe-Universität Frankfurt, Frankfurt, Germany Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Mexico City, Mexico Instituto de Física, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil Instituto de Física, Universidad Nacional Autónoma de México, Mexico City, Mexico iThemba LABS, National Research Foundation, Somerset West, South Africa Jeonbuk National University, Jeonju, Republic of Korea Johann-Wolfgang-Goethe Universität Frankfurt Institut für Informatik, Fachbereich Informatik undMathematik, Frankfurt, Germany Joint Institute for Nuclear Research (JINR), Dubna, Russia Korea Institute of Science and Technology Information, Daejeon, Republic of Korea KTO Karatay University, Konya, Turkey Laboratoire de Physique des 2 Infinis, Irène Joliot-Curie, Orsay, France Laboratoire de Physique Subatomique et de Cosmologie, Université Grenoble-Alpes, CNRS-IN2P3,Grenoble, France Lawrence Berkeley National Laboratory, Berkeley, California, United States Lund University Department of Physics, Division of Particle Physics, Lund, Sweden Nagasaki Institute of Applied Science, Nagasaki, Japan Nara Women’s University (NWU), Nara, Japan National and Kapodistrian University of Athens, School of Science, Department of Physics , Athens,Greece National Centre for Nuclear Research, Warsaw, Poland National Institute of Science Education and Research, Homi Bhabha National Institute, Jatni, India National Nuclear Research Center, Baku, Azerbaijan National Research Centre Kurchatov Institute, Moscow, Russia Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark Nikhef, National institute for subatomic physics, Amsterdam, Netherlands NRC Kurchatov Institute IHEP, Protvino, Russia NRC «Kurchatov» Institute - ITEP, Moscow, Russia NRNU Moscow Engineering Physics Institute, Moscow, Russia Nuclear Physics Group, STFC Daresbury Laboratory, Daresbury, United Kingdom Nuclear Physics Institute of the Czech Academy of Sciences, ˇRež u Prahy, Czech Republic Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States Ohio State University, Columbus, Ohio, United States Petersburg Nuclear Physics Institute, Gatchina, Russia Physics department, Faculty of science, University of Zagreb, Zagreb, Croatia
Physics Department, Panjab University, Chandigarh, India
Physics Department, University of Jammu, Jammu, India
Physics Department, University of Rajasthan, Jaipur, India
Physikalisches Institut, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
Physik Department, Technische Universität München, Munich, Germany
Politecnico di Bari, Bari, Italy
Research Division and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum fürSchwerionenforschung GmbH, Darmstadt, Germany
Rudjer Boškovi´c Institute, Zagreb, Croatia ψ v and v in Pb–Pb collisions at √ s NN = .
02 TeV ALICE Collaboration
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
Saha Institute of Nuclear Physics, Homi Bhabha National Institute, Kolkata, India
School of Physics and Astronomy, University of Birmingham, Birmingham, United Kingdom
Sección Física, Departamento de Ciencias, Pontificia Universidad Católica del Perú, Lima, Peru
St. Petersburg State University, St. Petersburg, Russia
Stefan Meyer Institut für Subatomare Physik (SMI), Vienna, Austria
SUBATECH, IMT Atlantique, Université de Nantes, CNRS-IN2P3, Nantes, France
Suranaree University of Technology, Nakhon Ratchasima, Thailand
Technical University of Košice, Košice, Slovakia
The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Cracow, Poland
The University of Texas at Austin, Austin, Texas, United States
Universidad Autónoma de Sinaloa, Culiacán, Mexico
Universidade de São Paulo (USP), São Paulo, Brazil
Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
Universidade Federal do ABC, Santo Andre, Brazil
University of Cape Town, Cape Town, South Africa
University of Houston, Houston, Texas, United States
University of Jyväskylä, Jyväskylä, Finland
University of Liverpool, Liverpool, United Kingdom
University of Science and Technology of China, Hefei, China
University of South-Eastern Norway, Tonsberg, Norway
University of Tennessee, Knoxville, Tennessee, United States
University of the Witwatersrand, Johannesburg, South Africa
University of Tokyo, Tokyo, Japan
University of Tsukuba, Tsukuba, Japan
Université Clermont Auvergne, CNRS/IN2P3, LPC, Clermont-Ferrand, France
Université de Lyon, Université Lyon 1, CNRS/IN2P3, IPN-Lyon, Villeurbanne, Lyon, France
Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France, Strasbourg, France
Université Paris-Saclay Centre d’Etudes de Saclay (CEA), IRFU, Départment de Physique Nucléaire(DPhN), Saclay, France
Università degli Studi di Foggia, Foggia, Italy
Università degli Studi di Pavia, Pavia, Italy
Università di Brescia, Brescia, Italy
Variable Energy Cyclotron Centre, Homi Bhabha National Institute, Kolkata, India
Warsaw University of Technology, Warsaw, Poland
Wayne State University, Detroit, Michigan, United States
Westfälische Wilhelms-Universität Münster, Institut für Kernphysik, Münster, Germany
Wigner Research Centre for Physics, Budapest, Hungary
Yale University, New Haven, Connecticut, United States