T. Yamanishi et al., HARD PROCESSES WITH SPIN-DEPENDENT PARTON DISTRIBUTIONS, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 402(2-3), 1998, pp. 291-293
To test a possible color-octet contribution of heavy quarkonium produc
tions, we propose psi'-productions for small-p(T) regions, where the c
olor-singlet psi' state cannot be produced by the gluon-gluon fusion o
wing to charge conjugation. We also point out that these processes are
very useful to deduce informations of spin-dependent gluon distributi
ons Delta g.