# Transverse momentum dependent multiplicities of hadrons produced in DIS at COMPASS

## TL;DR

This paper reports on the measurement of transverse momentum dependent multiplicities of charged hadrons in deep inelastic scattering at COMPASS, providing new insights into hadron production mechanisms.

## Contribution

It presents the first preliminary results of transverse momentum dependent multiplicities in DIS using a liquid hydrogen target at COMPASS, expanding previous isoscalar target measurements.

## Key findings

- Multiplicity dependence on $P_{hT}^2$, $x$, $Q^2$, and $z$ variables
- First results from 2016-2017 data at COMPASS
- Enhanced understanding of hadron transverse momentum distributions

## Abstract

The COMPASS Collaboration measured the transverse momentum dependent multiplicities of charged hadrons produced in Deep Inelastic Scattering (DIS) off unpolarized protons. Complementing previous COMPASS measurements obtained with an isoscalar target, the data have been collected in 2016 and 2017 with 160 GeV/$c$ muon beams and a liquid hydrogen target. The multiplicities are studied as a function of the square of the hadron transverse momentum with respect to the virtual photon direction $P_{hT}^2$ in bins of the Bjorken variable $x$, of the photon virtuality $Q^2$ and of the fraction $z$ of the photon energy carried by the hadron. Preliminary results of this analysis, performed on a fraction of the available data sample, are shown here for the first time.