# Measurement of prompt and nonprompt J/psi production in pp and pPb collisions at sqrt(s[NN]) = 5.02 TeV

## TL;DR

This study measures prompt and nonprompt J/psi meson production in pp and pPb collisions at 5.02 TeV, revealing small nuclear effects and insights into cold nuclear matter influences across a wide kinematic range.

## Contribution

It provides the first detailed differential cross sections and nuclear modification factors for J/psi production in pp and pPb collisions at this energy, including prompt and nonprompt components.

## Key findings

- Small modifications of J/psi cross sections in pPb relative to pp.
- Significant decrease in R[FB] with increasing transverse energy at large pseudorapidities.
- Wide kinematic coverage offers new insights into cold nuclear matter effects.

## Abstract

This paper reports the measurement of J/psi meson production in proton-proton (pp) and proton-lead (pPb) collisions at a center-of-mass energy per nucleon pair of 5.02 TeV by the CMS experiment at the LHC. The data samples used in the analysis correspond to integrated luminosities of 28 inverse picobarns and 35 inverse nanobarns for pp and pPb collisions, respectively. Prompt and nonprompt J/psi mesons, the latter produced from the decay of B mesons, are measured in their dimuon decay channels. Differential cross sections are measured in the transverse momentum range of 2 < pt < 30 GeV/c, and center-of-mass rapidity ranges of abs(y[CM]) < 2.4 (pp) and -2.87 < y[CM] < 1.93 (pPb). The nuclear modification factor, R[pPb], is measured as functions of both pt and y[CM]. Small modifications of the J/psi cross sections are observed in pPb relative to pp collisions. The ratio of J/psi production cross sections in p-going and Pb-going directions, R[FB], studied as functions of pt and y[CM], shows a significant decrease for increasing transverse energy deposited at large pseudorapidities. These results, which cover a wide kinematic range, provide new insight on the role of cold nuclear matter effects on prompt and nonprompt J/psi production.