Photoproduction of ${\psi }^{\prime }$ as a Test of Color-Octet Model

Abstract

We have calculated the cross section of ${\psi }^{\prime }$ photoproduction at small-$p_T$ regions in polarized $\gamma p$ collisions for testing the color-octet model, which is based on NRQCD factorization formalism. We show that the measurement of the two-spin asymmetry of this process might be effective to constrain the value of NRQCD matrix elements.

Comments: 4 pages including 2 ps-figures, use sprocl.sty and psfig.tex, Latex. Talk given at the 1998 YITP Workshop on "QCD and Hadron Physics", (Kyoto, Japan, Oct. 14-16, 1998)