Differential cross sections, charge production asymmetry, and spin-density matrix elements for charged D* (2010) charmed meson produced in 500 GeV/c charged pion-nucleon interactions.

摘要

Differential cross sections for the production of D*+/-(2010) mesons produced in 500 GeV/ c pi--nucleon interactions from Fermilab experiment E791, are reported as functions of Feynman-x (x F) and transverse momentum squared ( p2T ) and fitted to standard distributions. The D* +/- charge asymmetry and spin-density matrix elements as functions of these variables are also reported. The asymmetry curve is compared to P YTHIA Monte Carlo models. Investigation of the spin-density matrix elements shows no evidence of polarization. The average values of the spin alignment are ⟨eta⟩ = 0.01 +/- 0.02 and -0.01 +/- 0.02 for leading and non-leading particles, respectively.