Measurement of heavy-flavour production as a function of multiplicity in pp and p–Pb collisions with ALICE

In these proceedings results are presented from the measurement of open heavy-flavour production as a function of charged-particle multiplicity in pp collisions at s=7 TeV and p–Pb collisions at sNN=5.02 TeV recorded with the ALICE detector in 2010 and 2013, respectively. D0, D+ and D*+ mesons are reconstructed from their hadronic decay channels in the central rapidity region, and their production yields are measured in various multiplicity and pTpT intervals.The per-event yields of D mesons in the various multiplicity intervals, normalized to their multiplicity-integrated value, and their evolution with pTpT are measured for pp and p–Pb collisions to study the contribution of Multi-Parton Interactions (MPIs) to open charm production in the two systems. The nuclear modification factor of D mesons in p–Pb collisions, defined as the ratio of the D-meson yields in p–Pb and pp collisions scaled by the average number of binary collisions 〈Ncoll〉〈Ncoll〉, is discussed in terms of its dependence on the event activity. Several experimental estimators of the event activity are used in order to assess the role of kinematic biases.