AnDY : Overview and Plans Feasibility Test of Large Rapidity Drell-Yan Production at RHIC

Understand

Measuring the single transverse spin asymmetry $A_N$ for large $x_F$ Drell-Yan production provides the most robust test of our current theoretical understanding of transverse proton spin structure.

• This includes a measurement of the predicted sign change of the Sivers function in comparison to that found in SIDIS data.
• The first year of a feasibility test has been completed to define the requirements for measuring large $x_F$ Drell-Yan production at RHIC.
• The impact of colliding beams at a third IR at RHIC was found to be negligible and a rich jet-triggered data sample was acquired by AnDY in RHIC Run 11.