Speaker
Description
One of the primary goals of the STAR spin program is to determine the spin-dependent gluon distribution, ∆G, of the proton. Recent measurements of the longitudinal double-helicity asymmetry, ALL, from inclusive jets place strong constraints on ∆G and, for the first time, find evidence for non-zero gluon polarization values for partonic momentum fraction x greater than 0.05. In contrast to inclusive jets, di-jet correlation measurements provide access to partonic kinematics, at leading order, and thus give better constraints on the behavior of ∆G as a function of gluon momentum fractions. Furthermore, di-jet measurements at forward rapidity probe the lower x values where ∆G is poorly constrained. Status of the first measurement of ALL for di-jet with −0.8 < η1 < 0.8 and 0.8 < η2 < 1.8, from 2009 proton+proton collisions at √s = 200 GeV will
be presented.
