Double-parton scattering effects in double charm production within gluon fragmentation scenario

TL;DR

This paper investigates charm meson pair production at the LHCb, highlighting the role of double-parton scattering and gluon fragmentation mechanisms, which enhance cross sections and alter correlation patterns.

Contribution

It introduces new double gluon and mixed production mechanisms with gluon fragmentation, expanding the understanding of charm pair production in proton-proton collisions.

Findings

Double-parton scattering significantly contributes to charm pair production.

Gluon fragmentation mechanisms increase cross sections.

New correlation patterns are predicted due to additional mechanisms.

Abstract

We discuss charm $D^0 D^0$ meson-meson pair production in the forward rapidity region related to the LHCb experimental studies at $\sqrt{s}$ = 7 TeV. We consider double-parton scattering mechanisms of double $c \bar c$ production and subsequent standard $cc \to D^{0}D^{0}$ scale-independent hadronization as well as new double $g$ and mixed $g c\bar c $ production mechanisms with $gg \to D^{0}D^{0}$ and $gc \to D^{0}D^{0}$ scale-dependent hadronization. The new scenario with gluon fragmentation components results also in a new single-parton scattering mechanism of $gg$ production which is also taken here into account. Results of the numerical calculations are compared with the LHCb data for several correlation observables. The new mechanisms lead to a larger cross sections and to slightly different shapes of the calculated correlation observables.