Measurement of Nucleon Spin Structure at RHIC

This grant supports the participation of the Penn State University in

the STAR experiment at Brookhaven, including a full time research

associate, Akio Ogawa, at Brookhaven Lab. The principal interest of the

Penn State group involves the study of proton spin structure with

experiments using polarized proton beams at RHIC. The approved upgrades

to the STAR detector for this physics include an EMC (Electro-Magnetic

Calorimeter). As this system comes online, STAR will be capable of

reconstructing the higher rate, higher transverse momentum interactions

that are needed for polarized structure function measurements. The

utilization of these new features for a meaningful measurement of proton

spin structure presents a very large software challenge. Penn State is

developing software that will be required to simulate, collect and

analyzed these data from STAR. Some polarized proton running at RHIC is

expected each year for the next several years and will likely be in

increasingly important component of the STAR program. The central

objective of these experiments will be the measurement of the

contribution of gluon fields to the proton spin.