Production and polarization of $Λ_c^+$ and the charm of the proton

Abstract

We propose a two-component model involving the parton fusion mechanism and recombination of a $ud$ valence diquark with a sea $c$-quark of the incident proton to describe $Λ_c^+$ inclusive production in $pp$ collisions. We also study the polarization of the produced $Λ_c^+$ in the framework of the Thomas Precession Model for polarization. We show that a measurement of the $Λ_c$ polarization is a sensitive test of its production mechanism. In particular the intrinsic charm model predicts a positive polarization for the $Λ_c$ within the framework of the Thomas Precession Model, while according to the model presented here the $Λ_c$ polarization should be negative. The measurement of the $Λ_c$ polarization provides a close examination of intrinsic charm Fock states in the proton and give interesting information about the hadroproduction of charm.

references to figures corrected. Final version to appear in Physical Review D