Polarization phenomena in open charm photoproduction processes

We analyze polarization effects in associative photoproduction of pseudoscalar ($\bar{D}$) charmed mesons in exclusive processes $\gamma+ N\to Y_c +\bar{D}$, $Y_c=\Lambda_c^+$, $\Sigma_c$. Circularly polarized photons induce nonzero polarization of the $Y_c$-hyperon with $x$- and $z$-components (in the reaction plane) and non vanishing asymmetries ${\cal A}_x$ and ${\cal A}_z$ for polarized nucleon target. These polarization observables can be predicted in model-independent way for exclusive $\bar{D}$-production processes in collinear kinematics. The T-even $Y_c$-polarization and asymmetries for non-collinear kinematics can be calculated in framework of an effective Lagrangian approach. The depolarization coefficients $D_{ab}$, characterizing the dependence of the $Y_c$-polarization on the nucleon polarization are also calculated.Comment: 36 pages 13 figure

D* and D Meson Production in Muon Nucleon Interactions at 160 GeV/c

Adolph C, Alekseev MG, Alexakhin VY, et al. D* and D Meson Production in Muon Nucleon Interactions at 160 GeV/c. Eur.Phys.J. C. 2012;72(12): 2253.The production of D* and D mesons in inelastic scattering of 160 GeV/c muonsoff a ^6LiD target has been investigated with the COMPASS spectrometer at CERNfor 0.003 (GeV/c)^2 0.6