Probe charmonium-nucleon interactions in high energy proton-proton collisions

TL;DR

This paper models charmonium production in proton-proton collisions, revealing non-Gaussian emission sources and enabling femtoscopic extraction of charmonium-proton interactions, including effects of excited states.

Contribution

It introduces a dynamic, non-Gaussian emission source model for charmonium-proton pairs, allowing direct experimental extraction of their interactions.

Findings

Emission source of charmonium-proton pairs is non-Gaussian.

Excited charmonium states significantly affect correlation functions.

Femtoscopic analysis can probe charmonium-nucleon interactions directly.

Abstract

We investigate charmonium production and the charmonium-nucleon correlation function in pp collisions using the EPOS4+CATS framework. For the first time, the emission source of charmonium-proton pairs is dynamically generated and found to be non-Gaussian. This enables a femtoscopic extraction of the charmonium-proton interaction directly from experimental correlation functions. Both ground and excited charmonium states are included. We found that the excited states induce sizable uncertainties even negative in the observed prompt $J/\psi$-proton correlation through feed-down effects, reflecting their stronger interactions.