Speaker
Dr
Michael McCumber
(Los Alamos National Laboratory)
Description
We explored measurements of transverse single spin asymmetries (SSA) in forward jet productions at RHIC energies, in high energy p+p and 3He+p collisions, prior to the construction of an Electron-Ion Collider (EIC). Forward jets produced at 200 GeV center-of-mass energy carry a non-vanishing SSA, as was shown by the AnDY experiment at RHIC. This left-right bias originates from a correlation between the parton's transverse-momentum and the nucleon’s transverse spin (Sivers distributions). Gauge invariance predicts that the Sivers distribution is process-dependent, and the Sivers distributions for jet production in hadron-hadron collisions have opposite signs compared to those in semi-inclusive Deep-Inelastic Scattering.
Through simulation studies, we show that valance quarks’ contributions to jet production can be effectively “flavor-ehanced” by tagged-jet, with additional requirements imposed on jet properties. For example, up- (down-) quark’s contribution can be effectively enhanced by requiring the leading particle in a jet to be positively (negatively) charged. We demonstrate that jet and “tagged-jet” SSA measurements at RHIC can be used to study quark Sivers distribution at high-x, and its process-dependency. Taking the PHENIX collaboration’s proposed sPHENIX detector upgrade as an example, we show that with additional instrumentation in the forward direction, an exciting program of forward jet spin-asymmetry measurements can be carried out in conjunction with the sPHENIX's Heavy Ion physics program.
Primary author
Dr
Michael McCumber
(Los Alamos National Laboratory)
Co-author
Xiaodong Jiang
(LANL)
