Parity-violating asymmetry of $W$ bosons produced in $p$-$p$ collisions

Abstract

The parity-violating asymmetry is an ideal tool to study the quark helicity distribution in the proton. We study the parity-violating asymmetry of $W^{\pm }$ bosons produced by longitudinally polarized $p$-$p$ collision in RHIC, based on predictions of quark distributions of the proton in the SU(6) quark-spectator-diquark model and a perturbative QCD based counting rule analysis. We find that the two models give nearly equal asymmetry for $W^{+}$ but that for $W^{-}$ quite different. Therefore future experiments on such quantity can help to clarify different predictions of the value $\Delta d(x)/d(x)$ at $x\to 1$ in the proton.

Comments: 11 Latex pages, 9 figures, final version to appear in NPA