J/psi Production via Fragmentation at the Tevatron

TL;DR

The overall theoretical estimate of the production of $\jpsi$ at large transverse momenta in $p\bar p$ collisions is shown to be nearly consistent with the experimental observation.

Abstract

The production of $\jpsi$ at large transverse momenta ($\pt > M_\jpsi$) in $p\bar p$ collisions is considered by including the mechanism of fragmentation. Both contributions of fragmentation to $\jpsi$ and of fragmentation to $χ$ states followed by radiative decay to $\jpsi$ are taken into account. The latter is found to be dominant and larger than direct production. The overall theoretical estimate is shown to be nearly consistent with the experimental observation.

Figures (8)

• Figure 1: One of the diagrams for the gluon fragmentation function at the scale $\mu = 2m_c$.
• Figure 2: One of the diagrams for the charm fragmentation function, at the scale $\mu = 3m_c$.
• Figure 3: One of the diagrams for the gluon fragmentation function to the $\chi$ states, at the scale $\mu = 2m_c$.
• Figure 4: One of the "perturbative" contributions to the induced gluon fragmentation function, at the scale $\mu = 4m_c$.
• Figure 5: Leading order differential cross sections due to various fragmentation processes: $c$, $g$, induced gluon fragmentation to ${J\!/\!\psi}$ and gluon fragmentation to $\chi$ followed by radiative decay to ${J\!/\!\psi}$ are shown. Parameters as in table \ref{['table1']}.