$J/\psi$ production in proton-proton collisions at ALICE LHC

A Large Ion Collider Experiment (ALICE) studies the strong interaction part (Quantum Chromo Dynamics) of the Standard Model at the CERN Large Hadron Collider. ALICE has been designed as a general-purpose heavy-ion detector in order to explore phenomena of strong interacting matter and the quark-gluon plasma (QGP) at extreme values of energy density and temperature in nucleus-nucleus collisions. Results are presented here on the study of J/\psiproduction in pp collisions at ALICE. In particular, a measurement of J/\psi cross-section at \sqrt{s} = 7 TeV energy has been performed, together with a study of a possible algorithm to separate primary J/\psi from those coming from decays of B hadrons. The validity of this algorithm in ALICE has been demonstrated using Monte-Carlo samples. The J/\psi particles have been searched exclusively in the decay channel J/\psi -> e+e−. The study focused on what would be achievable in a period of early running, with integrated luminosity of L=1.25 nb-1, at a proton-proton centre of mass collision energy of \sqrt{s} = 7 TeV.