Measurement of Collins asymmetries in inclusive production of pion pairs in e^+e^- collisions at BABAR

Abstract

We present a preliminary measurement of the Collins asymmetries in the inclusive process e^+e^- --> qqbar --> pi pi X at center-of-mass energy near 10.6 GeV. We use a data sample of 468 fb^(-1) collected by the BABAR experiment, and we consider pairs of charged pions produced in opposite jets in hadronic events. We confirm a non-zero Collins effect as observed by previous experiments, and we study the Collins asymmetry as a function of pion fractional energies and transverse momenta, and as a function of the polar angle of the analysis axis.