Penetrating intrinsic charm: evidence in data

TL;DR

This paper provides evidence for intrinsic charm in hadrons through nuclear dependence of open charm and J/Psi production, supporting the presence of less than 1% intrinsic charm in hadrons, consistent with recent experimental data.

Contribution

It offers a theoretical explanation for observed nuclear effects in charm production, supporting the existence of intrinsic charm in hadrons with quantitative analysis.

Findings

Enhanced nuclear dependence of open charm production at large Feynman x_F

Reproduction of SELEX experiment data

Evidence for intrinsic charm less than 1% in hadrons

Abstract

Nuclei are transparent for a heavy intrinsic charm (IC) component of the beam hadrons, what leads to an enhanced nuclear dependence of open charm production at large Feynman x_F. Indeed, such an effect was observed recently in the SELEX experiment. Our calculations reproduce well the data, providing strong support for the presence of IC in hadrons in amount less than 1%. Moreover, we performed an analysis of nuclear effects in J/Psi production and found a similar, although weaker effect