Measurement of D-meson production versus multiplicity in p-Pb collisions at s N N = 5.02 $$ \sqrt{{\mathrm{s}}_{\mathrm{NN}}}=5.02 $$ TeV

The measurement of prompt D-meson production as a function of multiplicity in p-Pb collisions at √sNN=5.02 TeV with the ALICE detector at the LHC is reported. D0, D+ and D∗+ mesons are reconstructed via their hadronic decay channels in the centre-of-mass rapidity range −0.96< ycms< 0.04 and transverse momentum interval 1< pT< 24 GeV/c. The multiplicity dependence of D- meson production is examined by either comparing yields in p-Pb collisions in different event classes, selected based on the multiplicity of produced particles or zero- degree energy, with those in pp collisions, scaled by the number of binary nucleon-nucleon collisions (nuclear modification factor) ; as well as by evaluating the per-event yields in p-Pb collisions in different multiplicity intervals normalised to the multiplicity- integrated ones (relative yields). The nuclear modification factors for D0, D+ and D∗+ are consistent with one another. The D-meson nuclear modification factors as a function of the zero-degree energy are consistent with unity within uncertainties in the measured pT regions and event classes. The relative D-meson yields, calculated in various pT intervals, increase as a function of the charged-particle multiplicity. The results are compared with the equivalent pp measurements at √s=7 TeV as well as with EPOS~3 calculations.