Possible solution of the J/psi production puzzle

TL;DR

This paper proposes a new approach to J/psi production that accounts for intermediate charm quark interactions, successfully matching experimental data and predicting predominantly longitudinal polarization.

Contribution

It introduces a scenario involving s-channel cut contributions and intermediate charm interactions, which improves the understanding of J/psi production mechanisms.

Findings

The s-channel cut contribution can be larger than the traditional color-singlet contribution.

The proposed model reproduces experimental data at low and mid transverse momenta.

J/psi produced are predominantly longitudinally polarized.

Abstract

We argue that the s-channel cut contribution to J/psi hadroproduction can be significantly larger than the usual cut contribution of the color-singlet mechanism, which is known to underestimate the experimental measurements. A scenario accounting for intermediate $c\bar(c)$ interactions is proposed that reproduces the data at low- and mid-range transverse momenta P_T from the Fermilab Tevatron and BNL Relativistiv Heavy Ion Collider. The J/psi produced in this manner are polarized predominantly longitudinally.