Charge asymmetry dependency of π/K anisotropic flow in U+U √s_(NN) = 193 GeV and Au+Au √s_(NN) = 200 GeV collisions at STAR

摘要

In this paper we present STAR's measurements of v_2 and v_3 for charged kaons and pions at low transverse momentum range (0.15 < pT < 0.5 GeV/c), as a function of event charge asymmetry (A_(ch)) in both U+U collisions at √s_(NN) = 193 GeV and Au+Au collisions at √s_(NN) = 200 GeV. We found that in 20% - 60% centrality, the ratio of slope parameters of Δv_3 (A_(ch)) to that of ?v_2(A_(ch)), is +3σ below the predicted value (1/3) from local charge conservation at freeze-out, indicating that it is unlikely that such effect can have a significant contribution to the splitting of elliptic flow of charged pions as a function of A_(ch). We also observed a smaller ?v_2(A_(ch)) slope for kaons relative to pions. Our measurements serve as important consistency checks for the phenomena suggested as the consequence of the chiral magnetic wave.