Feynman-xand transverse-momentum dependence ofD±andD0,D¯0production in 250 GeVπ−-nucleon interactions

We measure the differential cross section with respect to Feynman-x (${\mathit{x}}_{\mathit{F}}$) and transverse momentum (${\mathit{P}}_{\mathit{T}}$) for charm meson production using targets of Be, Al, Cu, and W. In the range 0.1${\mathit{x}}_{\mathit{F}}$0.7, d\ensuremath{\sigma}/${\mathit{dx}}_{\mathit{F}}$ is well fit by the form (1-${\mathit{x}}_{\mathit{F}}$${)}^{\mathit{n}}$ with n=3.9\ifmmode\pm\else\textpm\fi{}0.3. The difference between n values for ${\mathit{D}}^{\mathrm{\ensuremath{-}}}$ and ${\mathit{D}}^{+}$ is 1.1\ifmmode\pm\else\textpm\fi{}0.7. However, we find an asymmetry of 0.18\ifmmode\pm\else\textpm\fi{}0.06 favoring the production of ${\mathit{D}}^{\mathrm{\ensuremath{-}}}$ compared to ${\mathit{D}}^{+}$. In the lower ${\mathit{P}}_{\mathit{T}}$ range, 2 GeV, d\ensuremath{\sigma}/${\mathit{dP}}_{\mathit{T}}^{2}$ is well fit by the form exp(-b\ifmmode\times\else\texttimes\fi{}${\mathit{P}}_{\mathit{T}}^{2}$) with b=1.03\ifmmode\pm\else\textpm\fi{}0.06 ${\mathrm{GeV}}^{\mathrm{\ensuremath{-}}2}$, while in the higher ${\mathit{P}}_{\mathit{T}}$ range, 0.8 to 3.6 GeV, it is well fit by the form exp(-b'\ifmmode\times\else\texttimes\fi{}${\mathit{P}}_{\mathit{T}}$) with b'=2.76\ifmmode\pm\else\textpm\fi{}0.08 ${\mathrm{GeV}}^{\mathrm{\ensuremath{-}}1}$. The shape of the differential cross section has no significant dependence on atomic mass of the target material.