  This note will be part of Chapter 6.5 of the ALICE Physics Performance Report
(PPR), "ALICE Physics: Charm and Beauty", where the capabilities of ALICE for
the detection of open heavy flavour particles will be described.
  We define here the present ALICE baseline for what concerns the heavy flavour
production cross sections at LHC and the kinematical distributions of the heavy
quark pairs. We start by qualitatively assessing the Bjorken x regimes
accessible with charm and beauty measurements at LHC with ALICE (Section 1). In
Section 2 we report the most recent results (and the uncertainties) of the
next-to-leading order (NLO) pQCD calculations for the cross sections in pp
collisions at LHC energies. These results are extrapolated to Pb-Pb collisions
in Section 3.1 and to p-Pb collisions in Section 3.2, taking into account
nuclear shadowing and parton intrinsic transverse momentum broadening.Heavy
quark kinematics as given by the NLO pQCD calculation are reported in Section
4. We tuned the PYTHIA event generator in order to reproduce such results for
what concerns the c and b quarks transverse momentum distributions (Section 5).
Finally, we report the yields and transverse momentum distributions for D and B
mesons (Section 6).
