Photoproduction of the (Positive, Negative) D* Meson

Abstract

Using the broad band beam at FNAL, we have observed the photoproduction of the D('*+) (and D('*-)) meson, where D('*+) (--->) D('0)(pi)('+) and D('0) (--->) K('-)(pi)('+) (143 (+OR-) 20 events) or D('0) (--->) K(,s)(pi)('+)(pi)('-) (35 (+OR-) 11 events). The observation exploited the small D('*+)-D('0) mass difference to reduce the combinatoric background by 3 orders of magnitude. A variety of analysis techniques are presented to demonstrate that the D('*+) is created by a diffractive pair production mechanism, with a cross section given by

(sigma)((gamma) + N (--->) D('0)) = 160 (+OR-) 70 nb/nucleon

Finally we discuss the data in terms of a QCD production mechanism, photon gluon fusion, and attempt to fix certain parameters in the theory by using the D('*) P(,t) distribution.