Measurement of Transverse Single Spin Asymmetries in $\pi^0$ Production from $p^{\uparrow}+p$ and $p^{\uparrow}+A$ Collisions at STAR

Apr 12, 2016, 11:20 AM
SR4a (DESY Hamburg)


DESY Hamburg

Spin Physics WG6 Spin Physics


Mr Christopher Dilks (Pennsylvania State University)


In 2015 the first collisions between polarized protons and nuclei occurred at the Relativistic Heavy Ion Collider (RHIC), at a center-of-mass energy of $\sqrt{s_{NN}}=200$ GeV. Comparisons between spin asymmetries and cross-sections in $p+p$ production to those in $p+A$ production provide insight into nuclear structure, namely nuclear modification factors, nuclear dependence of spin asymmetries, and comparison to models with saturation effects. The transverse single spin asymmetry, $A_N$, has been measured in $\pi^0$ production in the STAR Forward Meson Spectrometer (FMS), an electromagnetic calorimeter covering a forward psuedorapidity range of $2.6<\eta<4$. Within this kinematic range, STAR has previously reported the persistence of large $\pi^0$ asymmetries with unexpected dependences on $p_T$ and event topology in $p+p$ collisions. This talk will compare these dependences to those in $p+A$ production.

Primary author

Mr Christopher Dilks (Pennsylvania State University)

Presentation materials