Measurement of single muons at forward rapidity in p+p collisions at root s=200 GeV and implications for charm production

Muonproduction at forward rapidity (1.5 <=|eta|<= 1.8) has been measured by the PHENIX experiment over the transverse momentum range 1 <= p(T)<= 3 GeV/c in root s=200 GeV p+p collisions at the Relativistic Heavy Ion Collider. After statistically subtracting contributions from light hadron decays an excess remains which is attributed to the semileptonic decaysof hadrons carrying heavy flavor, i.e. charm quarksor, at high p(T), bottom quarks. The resulting muonspectrum from heavy flavor decays is compared to PYTHIA and a next-to-leading-order perturbative QCDcalculation. PYTHIA is used to determine the charm quarkspectrum that would produce the observed muonexcess. The corresponding differential cross section for charm quarkproduction at forward rapidity is determined to be d sigma(c (c) over bar)/dy|(y=1.6)=0.243 +/- 0.013(stat.)+/- 0.105(data syst.)(-0.087)(+0.049)(PYTHIA syst.) mb.