J/ψ production in √s=200 GeV p+p collisions with the PHENIX detector at RHIC

The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) detects J/psi particles in the rapidity range \y\ < 0.35 using the electron-pair decay channel and in 1.2 < y < 2.2 using the muon-pair decay channel. Cross sections for the J/psi production in those rapidity ranges have been measured in p+p collisions at roots = 200 GeV in the RHIC Run 2001-2002 period (Run-2). As a result, Br(J/psi --> mu(+)mu(-))dsigma(J/psi)/dy\(y=1.7) = 37 +/- 7 (stat.) +/- 11 (syst.) nb and Br(J/psi --> e(+)e(-))dsigma(J/psi)/dy\(y=0) = 52 +/- 13 (stat.) +/- 18 (syst.) nb are obtained. Total cross section has been extracted by fitting these results to be sigma(J/psi) = 3.8 +/- 0.6 (stat.) +/- 1.3 (syst.) mub which is consistent with the perturbative QCD prediction.