Open charm production at the LHC - $k_{t}$-factorization approach

TL;DR

This paper analyzes open charm production at the LHC using the $k_t$-factorization approach, comparing various unintegrated gluon distribution models with experimental data, and finds that the Kimber-Martin-Ryskin model best matches observations.

Contribution

It evaluates different UGDF models within the $k_t$-factorization framework and identifies the KMR model as providing the best agreement with experimental data for charm production.

Findings

KMR UGDF matches experimental data well

Other UGDF models underpredict data

Good correlation predictions for D and anti-D mesons

Abstract

We discuss inclusive production of open charm in proton-proton scattering at LHC. The calculation is performed within the $k_t$-factorization approach. Different models of unintegrated gluon distributions (UGDF) from the literature are used. The theoretical transverse momentum as well as (pseudo)rapidity distributions of charmed mesons are compared with recent experimental data of ATLAS, ALICE and LHCb collaborations. Only the calculation with Kimber-Martin-Ryskin (KMR) UGDF gives results comparable to experimental ones. All other popular models of UGDF significantly underpredict experimental data. Several sources of uncertainties of the theoretical predictions are also studied in details. In addition we discuss correlations between $D$ and $\bar D$ mesons. Good description of experimental distribution in invariant mass and in relative azimuthal angle between $D$ and $\bar D$ mesons is achieved for the KMR UGDF. The considered correlation observables measured by the LHCb experiment were not discussed in other approaches in the literature.