QCD predictions for open charm meson production at the LHCb in a fixed-target experiment

Rafał Maciuła

doi:10.1103/physrevd.102.014028

Abstract

We investigate open charm meson production in fixed-target LHCb experiment at $\sqrt{s}=86.6$ GeV in $p+^4\!\mathrm{He}$ collisions. Theoretical calculations of charm cross section are done in the framework of the $k_{T}$-factorization approach. Its application in the kinematical range never examined before is carefully discussed. We consider different schemes for the calculations relevant for different unintegrated (transverse momentum dependent) parton densities in a proton. We include in the analysis both CCFM- and DGLAP-based models of unintegrated parton distributions appropriate for the considered kinematics. Integrated as well as differential cross sections as a function of $D^{0}$ meson rapidity and transverse momentum are shown and compared with the experimental data. As a reference point, predictions of next-to-leading order collinear approach are also presented and discussed. A very good agreement between the experimental data and the $k_{T}$-factorization predictions was obtained. Both the CCFM and the DGLAP-based frameworks for parton distributions in a proton are successfully used to explain the LHCb fixed-target open charm cross section.

Highlights

According to current knowledge and experimental abilities, production of heavy flavor is known as one of the best testing grounds to investigate foundations of the theory of hard QCD interactions
The numerical predictions have been done in the kT-factorization approach
Two different schemes of the calculations have been discussed depending on the model of unintegrated parton densities in a proton used in the analysis

Summary

Introduction

According to current knowledge and experimental abilities, production of heavy flavor is known as one of the best testing grounds to investigate foundations of the theory of hard QCD interactions. Theoretical studies of e.g., charm cross section in proton-proton collisions provide an unique precision tool in this context. Phenomenology of charm particles production at hadron colliders has been shown many times to be one of the most powerful tools in testing pQCD techniques. In the ongoing LHC era the activity in this context has increased significantly on both experimental and theoretical sides, since charm particles are copiously produced at currently available high energies. Various measurements of open charm meson production have been accomplished by the ALICE, ATLAS, CMS, and LHCb experiments in pp, pA, and AA reactions at different TeV-scale energies (from 2.76 to 13 TeV). During last years several phenomenological studies of open charm production at the LHC were performed, including inclusive D-meson During last years several phenomenological studies of open charm production at the LHC were performed, including inclusive D-meson (see e.g., Refs. [1,2,3,4,5]) and Λc-baryon

Objectives

Results

Conclusion