AAPPS Bulletin (Jul 2023)

Pion PDFs confronted by fixed-target charmonium production

  • Wen-Chen Chang,
  • Chia-Yu Hsieh,
  • Yu-Shiang Lian,
  • Jen-Chieh Peng,
  • Stephane Platchkov,
  • Takahiro Sawada

DOI
https://doi.org/10.1007/s43673-023-00085-4
Journal volume & issue
Vol. 33, no. 1
pp. 1 – 9

Abstract

Read online

Abstract The pion, as the Goldstone boson of the strong interaction, is the lightest QCD bound state and responsible for the long-range nucleon-nucleon interaction inside the nucleus. Our knowledge on the pion partonic structure is limited by the existing Drell-Yan data which are primarily sensitive to the pion valence-quark distributions. The recent progress of global analysis of pion’s parton distribution functions (PDFs) utilizing various experimental approaches are introduced. From comparisons between the pion-induced $$J/\psi$$ J / ψ and $$\psi (2S)$$ ψ ( 2 S ) production data with theoretical calculations using the CEM and NRQCD models, we show how these charmonium production data could provide useful constraints on the pion PDFs.

Keywords