Factorization of event-plane correlations over transverse momentum in relativistic heavy ion collisions in a multiphase transport model

Abstract

Momentum-space azimuthal harmonic event planes (EP) are constructed from final-state midrapidity particles binned in transverse momentum (pT ) in √ sNN = 200 GeV Au+Au collisions in a multi-phase transport (AMPT) model. The EP correlations between pT bins, corrected by EP resolutions, are smaller than unity. This indicates that the EP's decorrelate over pT in AMPT, qualitatively consistent with data and hydrodynamic calculations. It is further found that the EP correlations approximately factorize into single pT -bin EP correlations to a common plane. This common plane appears to be the momentum-space EP integrated over all pT , not the configurationspace participant plane (PP).

Collective flow and hydrodynamics in large and small systems at the LHC

“…The fluctuations in the longitudinal direction have also been investigated both in experiment and in theory [40,[182][183][184][185]. Ref.…”

Collective flow in 2.76 and 5.02 A TeV Pb + Pb collisions

“…In fact, the flow harmonics v n are not sensitive to the details of the initial condition models as along as balanced initial eccentricities can be generated with some tunable parameters. Other flow measurements, e.g., the event-plane correlations, symmetric cumu-lants, non-linear response coefficients, the de-correlation of the flow vector, etc., could reveal more details on initial state fluctuations and the non-linear hydrodynamic response [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49]. A systematic study of these flow observables will help us to test the model calculations and the extracted QGP viscosity as well as to further constrain the initial condition models.…”

“…In the past few years, various flow observables have been extensively measured and studied in 2.76 A TeV Pb + Pb collisions, including the integrated and differential flow harmonics [20][21][22][23][24][25][26][27], the event-by-event v n distributions [27][28][29][30], the event-plane correlations [31][32][33][34][35],the correlations between different flow harmonics (symmetric cumulants) [35][36][37][38][39][40][41], the p T -and η-dependent de-correlations of the flow vector [42][43][44][45][46][47][48][49], etc. Many of these flow observables reflect the information on the event-by-event initial state fluctuations and the non-linear evolution of the system, which provide constraints for the initial condition models and the QGP transport coefficients.…”

Angle and magnitude decorrelation in the factorization breaking of collective flow

“…The principal component decomposition of the flow correlation matrix (14) carries the information about the flow factorization breaking. The flow magnitude decorrelation discussed in the previous section involves a correlation of higher powers of the flow vectors.…”

“…The phenomenon is known as flow factorization breaking in pseudorapidity or transverse momentum. It has been measured experimentally [6][7][8][9] and calculated in models [5,[10][11][12][13][14]. It is found that the factorization breaking coefficient is sensitive to fluctuations in the initial state.…”