Nucleon strangeness polarization from varLambda /bar{varLambda } hyperon production in polarized proton\u2013proton collision at RHIC

Abstract

We calculate the inclusive production of a polarized varLambda or bar{varLambda } hyperon from the single longitudinally polarized proton and proton (pp) collision at RHIC. By comparing the data reported by the STAR Collaboration, we find that this process is sensitive to the polarization of strange and antistrange quarks of the proton in the experimental range. By introducing asymmetric coefficients with the minimization of chi ^2, we further identify the asymmetry of the polarized strange–antistrange quarks in the proton sea and find that the first moment is varDelta s approx -,0.025pm 0.019 for strange quark and varDelta bar{s} approx -,0.001pm 0.012 for antistrange quark, with central values agreeing with the light-cone meson–baryon fluctuation model prediction, the recent lattice QCD determination of strangeness polarization and results from a global QCD analysis given by the Jefferson Lab Angular Momentum (JAM) Collaboration.