# Double prompt $J/\psi$ hadroproduction in the parton Reggeization approach with high-energy resummation

## TL;DR

This paper investigates double prompt $J/$ hadroproduction using the parton Reggeization approach, providing predictions that largely agree with experimental data and highlighting the importance of high-energy resummation in certain kinematic regions.

## Contribution

It introduces the application of the parton Reggeization approach with high-energy resummation to double $J/$ production, improving theoretical predictions in high-energy collider physics.

## Key findings

- Predictions agree with ATLAS and CMS data at leading order.
- High-energy resummation enhances cross sections in large invariant mass and rapidity separation regions.
- Resummation improves the description of data in previously underestimated regions.

## Abstract

We study double prompt $J/\psi$ hadroproduction within the nonrelativistic-QCD factorization formalism adopting the parton Reggeization approach to treat initial-state radiation in a gauge invariant and infrared-safe way. We present first predictions for the cross section distributions in the transverse momenta of the subleading $J/\psi$ meson and the $J/\psi$ pair. Already at leading order in $\alpha_s$, these predictions as well as those for the total cross section and its distributions in the invariant mass $m_{\psi\psi}$ and the rapidity separation $|Y|$ of the $J/\psi$ pair nicely agree with recent ATLAS and CMS measurements, except for the large-$m_{\psi\psi}$ and large-$|Y|$ regions, where the predictions substantially undershoot the data. In the latter regions, BFKL resummation is shown to enhance the cross sections by up to a factor of two and so to improve the description of the data.