Multiparticle and charge-dependent azimuthal correlations in heavy-ion collisions at the Relativistic Heavy-Ion Collider

We study multiparticle azimuthal correlations in relativistic heavy-ion collisions at a center-of-mass energy of 200 GeV. We use the impact parameter-dependent Glasma model to initialize the viscous hydrodynamic simulation MUSIC and employ the UrQMD transport model for the low-temperature region of the collisions. In addition, we study effects of local charge and global momentum conservation among the sampled particles. With the exception of the lowest-order three-particle correlator $C_{112}$, our framework provides a good description of the existing charge-inclusive azimuthal correlation data for Au+Au and U+U collisions at the Relativistic Heavy-Ion Collider (RHIC). We also present results for charge-dependent two- and three-particle correlators in Au+Au and U+U collisions and make predictions for isobar (Ru+Ru and Zr+Zr) collisions to provide a much-needed baseline for the search for the chiral magnetic effect at RHIC.

Figure 1

The temperature dependence of the specific shear and bulk viscosity used in the hydrodynamic simulations. The yellow region indicates $T<145$ MeV, where we employ a hadronic transport model.

Figure 2

Charged hadron and identified particle yields (a) and their averaged transverse momentum $\langle p_T\rangle$ (b) compared with the PHENIX and STAR measurements [71, 72] as a function of centrality in Au+Au collisions at 200 GeV.

Figure 3

The two-particle anisotropic flow coefficient $v_n\left\{2\right\}$ for charged hadrons in Au+Au collisions at 200 GeV compared with experimental data from the STAR Collaboration [2, 73].

Figure 4

The two-particle and four-particle cumulant elliptic flow coefficient $v_2$ in Au+Au collisions (a) and U+U collisions (b) at RHIC, compared with experimental data from the STAR Collaboration [2, 74].

Figure 5

(a) Prediction for the two-particle and four-particle cumulant $v_2\left\{2\right\}$ and $v_2\left\{4\right\}$ in Ru+Ru and Zr+Zr collisions at 200 GeV. (b) Prediction for the higher-order harmonic flow coefficients $v_{3,4}\left\{2\right\}$ in Ru+Ru and Zr+Zr collisions.

Figure 6

The three-particle correlators involving higher-order harmonics compared with experimental data from the STAR Collaboration for Au+Au collisions at 200 GeV [2].

Figure 7

The three-particle correlators involving the first-order harmonic compared with experimental data from the STAR Collaboration for Au+Au collisions at 200 GeV [2].

Figure 8

The four-particle symmetric cumulants (a) and normalized symmetric cumulants (b) compared with experimental data from the STAR Collaboration in Au+Au collisions at 200 GeV [1].

Figure 9

The difference between opposite-sign and same-sign two-particle correlation functions $\mathrm{\Delta }{C}_1\left\{2\right\}=C_1\left\{2\right\}\left(\mathrm{OS}\right)-C_1\left\{2\right\}\left(\mathrm{SS}\right)$ scaled by number of participants $N_{\mathrm{part}}$ in Au+Au and U+U collisions. Results with and without imposing LCC and GMC are shown.

Figure 10

The difference between opposite-sign and same-sign two-particle correlation functions $\mathrm{\Delta }{C}_n\left\{2\right\}=C_n\left\{2\right\}\left(\mathrm{OS}\right)-C_n\left\{2\right\}\left(\mathrm{SS}\right)$ scaled by the number of charged particles $N_{\mathrm{ch}}$ in the rapidity interval $-1<\eta <1$ divided by 2 in Au+Au collisions at 200 GeV.

Figure 11

(a) The difference between opposite-sign and same-sign three-particle correlation functions $\mathrm{\Delta }{C}_{112}=C_{112}\left(\mathrm{OS}\right)-C_{112}\left(\mathrm{SS}\right)$ is scaled by the value of $N_{\mathrm{part}}/C_2\left\{2\right\}$ in every centrality bin in Au+Au and U+U collisions. (b) For $\mathrm{\Delta }{C}_{132}{N}_{\mathrm{part}}/C_2\left\{2\right\}$ and (c) for $\mathrm{\Delta }{C}_{123}{N}_{\mathrm{part}}/C_3\left\{2\right\}$. Here $C_2\left\{2\right\}$ and $C_3\left\{2\right\}$ are the second- and the third-order Fourier coefficients of the two-particle correlation of all charged particles. Results with and without imposing LCC and GMC are shown.

Figure 12

(a) Test of the scaling of $\frac{N_{\mathrm{ch}}}{2}\frac{\mathrm{\Delta }{C}_{112}}{C_2\left\{2\right\}}{K}_1$ as a function of centrality in Au+Au and U+U collisions. (b) Test of the scaling of $\frac{\mathrm{\Delta }{C}_{132}}{C_2\left\{2\right\}}\frac{K_1}{K_2}$.

Figure 13

The difference between opposite-sign and same-sign two-particle correlation functions $\mathrm{\Delta }{C}_1\left\{2\right\}=C_1\left\{2\right\}\left(\mathrm{OS}\right)-C_1\left\{2\right\}\left(\mathrm{SS}\right)$ scaled by the number of participants $N_{\mathrm{part}}$ in Ru+Ru and Zr+Zr collisions. Results include LCC and GMC.

Figure 14

The difference between opposite-sign and same-sign three-particle correlation functions $\mathrm{\Delta }{C}_{112}=C_{112}\left(\mathrm{OS}\right)-C_{112}\left(\mathrm{SS}\right)$ is scaled by the value of $N_{\mathrm{part}}/C_2\left\{2\right\}$ in every centrality bin in Ru+Ru and Zr+Zr collisions. Here $C_2\left\{2\right\}$ is the second Fourier coefficient of the two-particle correlation of all charged particles. Results include LCC and GMC.