Cross-Section Measurements for Charm Production by 209-GeV Muons

Abstract

Interactions of 209-GeV muons in the multimuon spectrometer at Fermilab have yielded 20 072 dimuon final states, with (81\ifmmode\pm\else\textpm\fi{}10)% attributed to production of charmed states decaying to muons. The cross section for diffractive charm muoproduction is ${6.9}_{\ensuremath{-}1.4}^{+1.9}$ nb. Extrapolated to ${Q}^{2}=0$, the effective cross section for 178- (100-) GeV photons is ${750}_{\ensuremath{-}130}^{+180}$ (${560}_{\ensuremath{-}120}^{+200}$) nb.