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arXiv · 2402.02860

Constraining kaon PDFs from Drell-Yan and $J/\psi$ production

Wen-Chen Chang·Jen-Chieh Peng·Stephane Platchkov·Takahiro Sawada
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Abstract

The kaon parton distribution functions (PDFs) are poorly known due to paucity of kaon-induced Drell-Yan data. Nevertheless, these Drell-Yan data suggest a softer valence $u$ quark distribution of kaon than that of pion. We discuss the opportunity to constrain kaon PDFs utilizing existing kaon-induced $J/\psi$ production data. We compare the $K^- / \pi^-$ and $K^+ / \pi^+$ cross-section ratio data with calculations based on two global-fit parametrizations and two recent theoretical predictions for the kaon and pion PDFs, and test the results with two quarkonium production models. The $K^- / \pi^-$ cross-section ratio for $J/\psi$ production provides independent evidence of different valence quark distributions in pion and kaon. The $K^+ / \pi^+$ $J/\psi$ data are found to be sensitive to the gluon distribution in kaon. We show that these $J/\psi$ production data provide valuable constraints for evaluating the adequacy of currently available sets of kaon PDFs.

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Wen-Chen Chang, Jen-Chieh Peng, Stephane Platchkov, Takahiro Sawada. 2024-02-05. Constraining kaon PDFs from Drell-Yan and $J/\psi$ production. https://doi.org/10.1016/j.physletb.2024.138820

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