Abstract
We calculate the cross section for the production of mesons and baryons in proton-proton collisions at the LHC. The cross section for production of pairs is calculated within the -factorization approach with the Kimber-Martin-Ryskin unintegrated gluon distributions obtained on the basis of modern collinear gluon distribution functions. We show that our approach well describes the , , and experimental data. We try to understand recent ALICE and LHCb data for production with the independent parton fragmentation approach. The Peterson fragmentation functions are used. The fragmentation fraction and parameter for are varied. As a control plot we show the transverse momentum distributions of different species of mesons assuming standard values of the fragmentation fractions known from the literature. Although one can agree with the ALICE data using the standard estimation of model uncertainties, one cannot describe simultaneously the ALICE and the LHCb data with the same set of parameters. The fraction necessary to describe the ALICE data is much larger than the average value obtained from or experiments. No drastic modification of the shape of the fragmentation function is allowed by the new ALICE and LHCb data for production. We also discuss a possible dependence of the baryon-to-meson ratio on rapidity and transverse momentum as recent observations by the ALICE and LHCb collaborations seem to suggest. Three different effects are considered: the value of the parameter in the Peterson fragmentation function for , a kinematical effect related to the hadronization prescription, and a possible feed-down from higher charmed-baryon excitations. It seems very difficult, if not impossible, to understand the ALICE data within the considered independent parton fragmentation scheme.
1 More- Received 5 April 2018
DOI:https://doi.org/10.1103/PhysRevD.98.014016
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Published by the American Physical Society