Azimuthal correlations of heavy-flavor hadron decay electrons with charged particles in pp and p–Pb collisions at sNN\pmb {\sqrt{s_{\mathrm{{NN}}}}} = 5.02 TeV

International audienceThe azimuthal ($\Delta \varphi$) correlation distributions between heavy-flavor decay electrons and associated charged particles are measured in pp and p–Pb collisions at $\sqrt{s_{\mathrm{{NN}}}} = 5.02$ TeV. Results are reported for electrons with transverse momentum $4<p_{\textrm{T}}<16\textrm{GeV}/c$ and pseudorapidity $|\eta |<0.6$. The associated charged particles are selected with transverse momentum $1<p_{\textrm{T}}<7\textrm{GeV}/c$, and relative pseudorapidity separation with the leading electron $|\Delta \eta | < 1$. The correlation measurements are performed to study and characterize the fragmentation and hadronization of heavy quarks. The correlation structures are fitted with a constant and two von Mises functions to obtain the baseline and the near- and away-side peaks, respectively. The results from p–Pb collisions are compared with those from pp collisions to study the effects of cold nuclear matter. In the measured trigger electron and associated particle kinematic regions, the two collision systems give consistent results. The $\Delta \varphi$ distribution and the peak observables in pp and p–Pb collisions are compared with calculations from various Monte Carlo event generators

Measurement of the non-prompt D-meson fraction as a function of multiplicity in proton-proton collisions at s \sqrt{s} = 13 TeV

International audienceThe fractions of non-prompt (i.e. originating from beauty-hadron decays) D$^{0}$ and D$^{+}$ mesons with respect to the inclusive yield are measured as a function of the charged-particle multiplicity in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV with the ALICE detector at the LHC. The results are reported in intervals of transverse momentum (p$_{T}$) and integrated in the range 1 < p$_{T}$< 24 GeV/c. The fraction of non-prompt D$^{0}$ and D$^{+}$ mesons is found to increase slightly as a function of p$_{T}$ in all the measured multiplicity intervals, while no significant dependence on the charged-particle multiplicity is observed. In order to investigate the production and hadronisation mechanisms of charm and beauty quarks, the results are compared to PYTHIA 8 as well as EPOS 3 and EPOS 4 Monte Carlo simulations, and to calculations based on the colour glass condensate including three-pomeron fusion.[graphic not available: see fulltext