Massive c\bar c g - Calculation in Diffractive DIS and Diffractive D^* - Production at HERA

Abstract

We calculate the cross section for $c\bar{c}g$-production in diffractive DIS with finite quark masses at zero momentum transfer $t$. The calculation is done in the leading log(1/$x_P$) approximation and is valid in the region of high diffractive masses $M$ (small $\beta$). We apply our cross section formula including both $c\bar{c}$- and $c\bar{c}g$ in a Monte Carlo simulation to diffractive $D^{\ast \pm }$ meson production at HERA. We compare our predictions to results of H1 using three parameterizations for the unintegrated gluon density.

Comments: 11 pages, 5 figures