# Prompt $J/\psi$ production in associated with top quark pair at the LHC

## TL;DR

This paper studies prompt $J/\psi$ production associated with top quark pairs at the 13 TeV LHC, including direct and indirect contributions, and explores its potential detection to test heavy quarkonium production mechanisms.

## Contribution

It provides the first detailed calculation of prompt $J/\psi$ production with top pairs at NLO in the nonrelativistic QCD framework, including indirect contributions from heavier charmonia.

## Key findings

- $tar t J/\psi$ production can be potentially observed at the LHC.
- The $ ext{S}^{(8)}$ states dominate the production.
- Results can test heavy quarkonium production models.

## Abstract

In this work, we investigate the prompt $J/\psi$ production in associated with top quark pair to leading order in the nonrelativistic QCD factorization formalism at the LHC with $\sqrt{s} =13$ TeV. In addition to the contribution from direct $J/\psi$ production, we also include the indirect contribution from the directly produced heavier charmmonia $\chi_{cJ}$ and $\psi^\prime$. We present the numerical results for the total and differential cross sections and find that the $\sideset{^3}{^{(8)}_1}{\mathop{{S}}}$ states give the dominant contributions. The prompt $t\bar t J/\psi$ signatures at the LHC are analyzed in the tetralepton channel $pp\to (t\to W^+(\ell^+\nu)b) (\bar t \to W^-(\ell^- \bar \nu)\bar b) (J/\psi\to\mu^+\mu^-)$ and trilepton channel $pp\to (t\to W(q q^\prime)b) ( t \to W(\ell \nu) b) (J/\psi\to\mu^+\mu^-)$, with the $J/\psi$ mesons decaying into muon pair, and the top quarks decaying leptonically or hadronically. We find that $t\bar t J/\psi$ proudction can be potentially detected at the LHC, whose measurement is useful to test the heavy quarkonium production mechanism.