Speaker
Description
Transverse single spin asymmetries (TSSA) have been studied for some time to help understand proton substructure. Their study has led to new developments in the theory of nuclear structure to include not only the collinear momentum of partons but also their transverse momentum. These new frameworks, the transverse momentum dependent parton distribution functions (TMD) and the Twist-3 collinear factorization framework, need to be understood in a wide range of kinematic coverage and particle species. To this end the STAR experiment at the Relativistic Heavy Ion Collider (RHIC) spends a considerable effort to measure the TSSA of different particle species in a wide range of Bjorken-$x$ and $Q^2$. In particular, STAR has shown that the TSSA of inclusive jets reconstructed from electromagnetic showers (electromagnetic jets) in the forward pseudorapidity region are non-zero. This talk will show the dependence of the TSSA on the number of contributors in the electromagnetic jet in the pseudorapidity region of $2.6<\eta<4.2$ at $\sqrt{s}=200$~GeV and $\sqrt{s}=510$~GeV. The data shows a clear suppression of the TSSA with increasing number of contributors at both energies. It will also give an update on the analysis of TSSA of neutral pions using the STAR forward upgrade detectors at $\sqrt{s}=510$~GeV (2022 dataset) in a similar pseudorapidity range of $2.5<\eta<4$.
| Speaker confirmation | Yes |
|---|