Search for D production in pion-nucleon interactions.

Abstract

Results are presented of a measurement of the production of ${D}^{\mathrm{*}+}$ (${D}^{\mathrm{*}\mathrm{\ensuremath{-}}}$) in 250-GeV/c ${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$N interactions. We observe 2.1\ifmmode\pm\else\textpm\fi{}7.8 events corresponding to a charge-${D}^{\mathrm{*}}$ cross section \ensuremath{\sigma}(${D}^{\mathrm{*}}$) of 0.4\ifmmode\pm\else\textpm\fi{}1.5 \ensuremath{\mu}b/nucleon. When averaged with our previous measurement made at 200 GeV/c, the result is \ensuremath{\sigma}(${D}^{\mathrm{*}}$)=2.3\ifmmode\pm\else\textpm\fi{}1.0 \ensuremath{\mu}b/nucleon with (d\ensuremath{\sigma}/dx)${\ensuremath{\Vert}}_{x=0}$=4.6\ifmmode\pm\else\textpm\fi{}2.0 \ensuremath{\mu}b.