Investigating charm production and fragmentation via azimuthal correlations of prompt D mesons with charged particles in pp collisions at $\mathbf {\sqrt{ s} = 13}$ TeV

The collaboration
Eur.Phys.J.C 82 (2022) 335, 2022.

Abstract (data abstract)
The measurement of the azimuthal-correlation function of prompt D mesons with charged particles in pp collisions at a centre-of-mass energy of $\sqrt{s} =$ 13 TeV with the ALICE detector is reported, considering D$^{0}$, D$^{+}$, and D$^{*+}$ mesons in the transverse-momentum interval $3 < p_{\mathrm{T}} < 36$ GeV/$c$ at midrapidity ($|y| < 0.5$), and charged particles with $p_{\mathrm{T}} > 0.3$ GeV/$c$ and pseudorapidity $|\eta| < 0.8$. This measurement has an improved precision and provides an extended transverse-momentum coverage compared to previous ALICE measurements at lower energies. The study is also performed as a function of the charged-particle multiplicity, showing no modifications of the correlation function with multiplicity within uncertainties. The properties and the transverse-momentum evolution of the near- and away-side correlation peaks are studied and compared with predictions from various Monte Carlo event generators. The obtained results can provide constraints on the generators. Among those considered, PYTHIA8 and POWHEG+PYTHIA6 provide the best description of the measured observables.