Extraction of Kaon Partonic Distribution Functions from Drell-Yan and $J/\psi$ Production Data

TL;DR

This paper introduces the first extraction of kaon parton distribution functions using meson-induced Drell-Yan and $J/$ production data, revealing a harder strange valence distribution and similar gluon momentum fractions compared to pions.

Contribution

It extends the statistical model approach to kaon PDFs, providing the first global fit to relevant experimental data.

Findings

Kaon valence strange quark distribution is harder than up quark.

Kaon gluon distribution is similar to that of the pion.

Data are well described by the statistical model.

Abstract

We present an analysis to extract kaon parton distribution functions (PDFs) for the first time using meson-induced Drell-Yan and quarkonium production data. Starting from the statistical model first developed for determining the partonic structure of spin-1/2 nucleon and later applied to the spin-0 pion, we have extended this approach to perform a global fit to existing kaon-induced Drell-Yan and $J/\psi$ production data. These data are well described by the statistical model, allowing a first extraction of the kaon PDFs. We find that both the Drell-Yan and the $J/\psi$ data favor a harder valence distribution for strange quark than for up quark in kaon. The kaon gluon distribution is further constrained by the $J/\psi$ production data. In particular, the momentum fraction carried by gluons is found to be similar for pion and kaon.