Speaker
Description
The multiplicities of charged hadrons produced in the deep inelastic scattering (DIS) of muons off a proton target as a function of the hadron transverse momentum $P_{hT}$ are being measured by COMPASS using the data collected in 2016 and 2017 with a $160~\mathrm{GeV}/c$ muon beam and a liquid hydrogen target. Preliminary results of this analysis using a fraction of the full collected sample and a limited kinematic range will be shown. Namely, the range of photon virtuality $Q^2>1~(\mathrm{GeV}/c)^2$, Bjorken variable $0.003 < x < 0.4$ and fractional hadron energy $0.2 < z < 0.8$ is covered. The hadron transverse momentum squared extends in the region $0.02~(\mathrm{GeV}/c)^2 < P_{hT}^2 < 1~(\mathrm{GeV}/c)^2$, where the results offer an insight in the transverse motion of partons, as well as in the high-$P_{hT}^2$ region up to $3~(\mathrm{GeV}/c)^2$, where higher-order perturbative QCD contribution is expected to dominate. The results complement our previous ones, obtained with an isoscalar target in the same kinematic range.
