J/ψProduction in {the square root of }s = 200 GeV p+p Collisions with the PHENIX Detector at RHIC

摘要

The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) detects J/ψ 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/ψ production in those rapidity ranges have been measured in p+p collisions at {the square root of}s = 200 GeV in the RHIC Run 2001-2002 period (Run-2). As a result, Br(J/ψ→μ{sup}+μ{sup}-)dσ{sub}(J/ψ)/dy|{sub}(y=1.7) = 37±7 (stat.)±11 (syst.) nb and Br(J/ψ) →e{sup}+e{sup}-) dy|{sub}(y=0)=52±13 (stat.)±18 (syst.) nb are obtained. Total cross section has been extracted by fitting these results to beσ{sub}( J/ψ)= 3.8±0.6 (stat.) ± 1.3 (syst.) μb which is consistent with the perturbative QCD prediction.