Lambda polarization in pp -> pΛK^+ π^+π^-π^+π^-

Abstract

We show that there is a correlation between the invariant mass of the produced ΛK^+, ΛK^+π^+π^- or ΛK^+ π^+π^-π^+π^- system in the exclusive reaction pp\to pΛK^+π^+π^-π^+π^- and the longitudinal or transverse momentum of $Λ$. Together with the longitudinal and transverse momentum dependence of Lambda polarization observed in inclusive reactions, such a correlation implies a dependence of Lambda polarization on these invariant masses. The qualitative features of this dependence are consistent with the recent observation by E766 collaboration at BNL. A quantitative estimation has been made using an event generator for $pp$ collisions. A detailed comparison with the data is made.