Effects of momentum conservation on the analysis of anisotropic flow

N. Borghini, P. M. Dinh, J.-Y. Ollitrault, A. M. Poskanzer, S. A. Voloshin
2002 Physical Review C  
We present a general method for taking into account correlations due to momentum conservation in the analysis of anisotropic flow, either by using the two-particle correlation method or the standard flow vector method. In the latter, the correlation between the particle and the flow vector is either corrected through a redefinition (shift) of the flow vector, or subtracted explicitly from the observed flow coefficient. In addition, momentum conservation contributes to the reaction plane
more » ... on. Momentum conservation mostly affects the first harmonic in azimuthal distributions, i.e., directed flow. It also modifies higher harmonics, for instance elliptic flow, when they are measured with respect to a first harmonic event plane such as one determined with the standard transverse momentum method. Our method is illustrated by application to NA49 data on pion directed flow.
doi:10.1103/physrevc.66.014901 fatcat:4irqpnx2nvfq5guho7fdfe72j4