Probing Pion Valence Quark Distribution with Beam-charge Asymmetry of Pion-induced $J/ψ$ Production
Fuente:
arXiv
Guardado en:
| Autores principales: | , , , , |
|---|---|
| Formato: | Preprint |
| Publicado: |
2025
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1866909616721362944 |
|---|---|
| author | Chang, Wen-Chen Meyer-Conde, Marco Peng, Jen-Chieh Platchkov, Stephane Sawada, Takahiro |
| author_facet | Chang, Wen-Chen Meyer-Conde, Marco Peng, Jen-Chieh Platchkov, Stephane Sawada, Takahiro |
| contents | We consider the beam-charge asymmetry of the $J/ψ$ production cross sections in $π^-$- versus $π^+$-induced reactions on proton or nuclear targets. We show that the $J/ψ$ production cross section difference between $π^-$ and $π^+$ beams impinging on a proton target has a positive sign with a magnitude proportional to the product of pion's valence quark distribution, $V_π$, and proton's up and down valence quark distribution difference, $u^V - d^V$. The existing $J/ψ$ production data for $π^- + p$ and $π^+ + p$ at 39.5 and 200 GeV/c are consistent with the expected positive beam-charge asymmetry. The magnitude of the asymmetry is compared with calculations performed within two theoretical frameworks, the Color Evaporation Model (CEM) and the Non-Relativistic QCD (NRQCD) formalism. We also examine the beam-charge dependence for pion-induced $J/ψ$ production cross sections measured on the neutron-rich platinum target, and find good agreement between the data and theory for both the negative sign and the magnitude of the beam-charge asymmetry. The comparison between data and theoretical calculations for both proton and platinum targets suggests that the beam-charge asymmetry in pion-induced $J/ψ$ production is a viable method of accessing the valence quark distribution of the pion. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2503_18654 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Probing Pion Valence Quark Distribution with Beam-charge Asymmetry of Pion-induced $J/ψ$ Production Chang, Wen-Chen Meyer-Conde, Marco Peng, Jen-Chieh Platchkov, Stephane Sawada, Takahiro High Energy Physics - Phenomenology High Energy Physics - Experiment Nuclear Experiment We consider the beam-charge asymmetry of the $J/ψ$ production cross sections in $π^-$- versus $π^+$-induced reactions on proton or nuclear targets. We show that the $J/ψ$ production cross section difference between $π^-$ and $π^+$ beams impinging on a proton target has a positive sign with a magnitude proportional to the product of pion's valence quark distribution, $V_π$, and proton's up and down valence quark distribution difference, $u^V - d^V$. The existing $J/ψ$ production data for $π^- + p$ and $π^+ + p$ at 39.5 and 200 GeV/c are consistent with the expected positive beam-charge asymmetry. The magnitude of the asymmetry is compared with calculations performed within two theoretical frameworks, the Color Evaporation Model (CEM) and the Non-Relativistic QCD (NRQCD) formalism. We also examine the beam-charge dependence for pion-induced $J/ψ$ production cross sections measured on the neutron-rich platinum target, and find good agreement between the data and theory for both the negative sign and the magnitude of the beam-charge asymmetry. The comparison between data and theoretical calculations for both proton and platinum targets suggests that the beam-charge asymmetry in pion-induced $J/ψ$ production is a viable method of accessing the valence quark distribution of the pion. |
| title | Probing Pion Valence Quark Distribution with Beam-charge Asymmetry of Pion-induced $J/ψ$ Production |
| topic | High Energy Physics - Phenomenology High Energy Physics - Experiment Nuclear Experiment |
| url | https://arxiv.org/abs/2503.18654 |