Valence Quark and Gluon Distributions of Kaon from J/Psi Production

TL;DR

This paper investigates the valence quark and gluon distributions in kaons using J/psi production data, providing new insights that support the idea of a softer valence u quark distribution in kaons compared to pions.

Contribution

It demonstrates the feasibility of extracting kaon parton distributions from J/psi production data and offers independent evidence for a softer valence u quark distribution in kaons.

Findings

NA3 data supports a softer valence u quark distribution in kaons.

Evidence suggests different gluon distributions in kaons and pions.

J/psi production data can be used to probe kaon parton structure.

Abstract

The only experimental information on the parton distribution of kaons was obtained from the scarce kaon-induced Drell-Yan cross section data. From these data, evidence for a valence $u$ quark distribution of kaon softer than that of pion was found. We study the feasibility to extract kaon's valence quark distribution via the existing kaon-induced J/psi production data. We compare the NA3 data on the K- / pi- and K+ / pi+ ratios for J/psi production on a platinum target with theoretical calculations based on the color-evaporation model. We show that the NA3 data on J/psi production provide an independent evidence for a valence $u$ quark distribution softer in kaon than in pion. The data also suggest different gluon distributions for kaon and pion.