D and D meson production in muon nucleon interactions at 160 GeV/c.

The production of D and D mesons in inelastic scattering of 160 GeV/c muons off a LiD target has been investigated with the COMPASS spectrometer at CERN for 0.003 (GeV/c)< Q<10 (GeV/c) and 3×10< x<0.1. The study is based on 8100 events where a D or $\bar{D}^{0}$ is detected subsequently to a D or D decay, and on 34000 events, where only a D or $\bar{D}^{0}$ is detected. Kinematic distributions of D, D and $K_{2}^{*} (1430)$ are given as a function of their energy E, transverse momentum p, energy fraction z, and of the virtual photon variables ν, Q and x. Semi-inclusive differential D production cross-sections are compared with theoretical predictions for D production via photon-gluon fusion into open charm. The total observed production cross-section for D mesons with laboratory energies between 22 and 86 GeV is (1.9±0.4) nb. Significant cross-section asymmetries are observed between D and D production for ν<40 GeV and z>0.6. [ABSTRACT FROM AUTHOR]