"Measurement of open-charm production as a function of charged-particle
multiplicity in pp collisions at $\sqrt{s}$ = 7 TeV with ALICE"
Dr. Renu Bala,
University of Jammu, India
The ALICE detector was designed for the study of the high energy-density QCD matter
produced in high-energy heavy-ion collisions. Heavy quarks (charm and beauty) are
important probes of this matter, as they are produced in initial hard scattering
processes and they experience all the stages of the medium evolution. Therefore
measurements of heavy-flavour hadron production provide important information on the
early stage of the collision and the parton-medium interaction. Open heavy-flavour
production measurements in pp collisions provide the necessary baseline to understand
the results in Pb-Pb collisions and a test of pQCD (perturbative quantum chromodynamics)
calculations. Furthermore, the study of open heavy-flavour production in pp collisions
as a function of charged-particle multiplicity allows us to investigate the interplay
between hard and soft mechanisms in particle production. In particular, it could give
insight into the role of multi-parton interactions (MPI), i.e. several hard partonic
interactions occurring in a single collision at high centre-of-mass energies.
The measurement of open heavy-flavour per-event yields as a function of
charged-particle multiplicity in pp collisions at $\sqrt{s}$ =7 TeV recorded with the
ALICE detector will be presented. D$^0$, D$^+$ and D$^{*+}$ mesons are reconstructed
from their hadronic decay channels in the central rapidity region, and their yields are
measured in different multiplicity and $p_{\rm T}$ intervals. These yields will be
compared to the results obtained for inclusive and non-prompt J/$\psi$. Finally,
comparisons with model calculations will be reported.