Measurement of the inclusive $D*^{+-}$ production in $\gamma \gamma$ collisions at LEP

The inclusive production of D sup * sup+- mesons in two-photon collisions is measured with the ALEPH detector at e sup + e sup - centre-of-mass energies from 183 GeV to 209 GeV. A total of 360 +-27D sup * sup+- meson events are observed from an integrated luminosity of 699 pb sup - sup 1. Contributions from direct and single-resolved processes are separated using the ratio of the transverse momentum p sub t sup D sup * sup+- of the D sup * sup+- to the visible invariant mass W sub v sub i sub s of the event. Differential cross sections of D sup * sup+- production as functions of p sub t sup D sup * sup+- and the pseudorapidity vertical stroke eta sup D sup * sup+- vertical stroke are measured in the range 2 GeV/c<p sub t sup D sup * sup+-<12 GeV/c and vertical stroke eta sup D sup * sup+- vertical stroke <1.5. They are compared to next-to-leading order (NLO) perturbative QCD calculations. The extrapolation of the integrated visible D sup * sup+- cross section to the total charm cross section, based on the Pythia Monte Carlo program, yields sigma(e sup + e sup -->e sup + e sup - c anti c) sub l sub e sub f sub t sub a sub n sub g sub l sub e subsq root sub ( sub s sub ) sub r sub i sub g sub h sub t sub a sub n sub g sub l sub e sub = sub 1 sub 9 sub 7 sub G sub e sub V =731+-74 sub s sub t sub a sub t+-47 sub s sub y sub s sub t+-157 sub e sub x sub t sub r pb. (orig.)