Speaker
Description
In recent years the STAR Collaboration collected a large sample
of ultra-peripheral heavy-ion collisions. The photoproduction of
J/
nucleon or nucleus. We will present results from a statistically
large sample of J/
result comes from the study of the
show two components, from scattering off the entire Au nucleus or off
individual nucleons inside the nucleus. From a smaller sample of J/
production in p+Au collisions, with polarized protons, we will discuss
the status of a first study of the asymmetry of J/
A non-zero asymmetry would be the first measure of the generalized
parton distribution,
orbital angular momentum of partons in the nucleon. The present study
is a proof-of-principle, and we will discuss the possibilities with
larger data samples from future polarized p+p and p+Au RHIC runs.