Multiparticle azimuthal cumulants in p+Pb collisions from a multiphase transport model

A new subevent cumulant method was recently developed, which can significantly reduce the nonflow contributions in long-range correlations for small systems compared to the standard cumulant method. In this work, we study multiparticle cumulants in p+Pb collisions at sNN=5.02 TeV with a multiphase transport model (AMPT), including two-and four-particle cumulants (c2{2} and c2{4}) and symmetric cumulants [SC(2, 3) and SC(2, 4)]. Our numerical results show that v2{2} is consistent with the experimental data, while the magnitude of c2{4} is smaller than the experimental data, which may indicate that either the collectivity is underestimated or some dynamical fluctuations are absent in the AMPT model. For the symmetric cumulants, we find that the results from the standard cumulant method are consistent with the experimental data, but those from the subevent cumulant method show different behaviors. The results indicate that the measurements from the standard cumulant method are contaminated by nonflow effects, especially when the number of produced particles is small. The subevent cumulant method is a better tool to explore the real collectivity in small systems.