A remark on the sign change of the four-particle azimuthal cumulant in small systems

Abstract

The azimuthal cumulants, c2{2} and c2{4}, originating from the global conservation of transverse momentum in the presence of hydro-like elliptic flow are calculated. We observe the sign change of c2{4} for small number of produced particles. This is in a qualitative agreement with the recent ATLAS measurement of multi-particle azimuthal correlations with the subevent cumulant method.