Elliptic flow of hadrons in equal-velocity quark combination mechanism in relativistic heavy-ion collisions

We apply a quark combinationmodel with equalvelocity combination (EVC) approximation to study the elliptic flow (v(2)) of hadrons in heavy-ion collisions in a wide collision energy range (root s(NN) = 27-5020 GeV). Utilizing the simple relationship between v(2) of hadrons and those of quarks under EVC, we find that v(2) of up/down quarks obtained by experimental data of proton is consistent with that obtained by data of Lambda and Xi. v(2) of strange quarks obtained by data of O is consistent with that obtained by data of. and., and at RHIC energies it is also consistent with that obtained by data of f. This means that v(2) of these hadrons have a common quark-level source. Using data of D-0, we obtain v(2) of charm quarks with pT less than or similar to 6 GeV/c. We find that under EVC charm quark dominates v(2) of D mesons at low pT but light-flavor quarks significantly contribute to v(2) of D mesons in the range 3 less than or similar to pT less than or similar to 8 GeV/c. We predict v(2) of charmed baryons Lambda(+)(c) and Xi(0)(c) which show a significant enhancement at intermediate pT due to the double contribution of light-flavor quarks. The properties of the obtained quark v(2) under EVC are studied and a regularity for v(2) of quarks as the function of pT/m is found.

Automated summary

The study utilizes a quark combination model to analyze the elliptic flow of hadrons in heavy-ion collisions, revealing a common quark-level source for the v(2) of different hadrons. By obtaining quark v(2) from experimental data and predicting the v(2) of charm quark baryons, the study provides insights into the contributions of different quark flavors to the v(2) of hadrons.