Speaker
Description
Overview of transverse spin physics in the PHENIX experiment
We would like to present an overview of recent results from the PHENIX collaboration on spin physics using a transversely polarized proton beam. Several experiments have been conducted at RHIC in the past decade using such beam polarization in proton-proton collisions. Recently, polarized proton-ion collisions have also been studied.
Important recent transverse spin measurements in PHENIX include the transverse spin asymmetry in light meson production (π°, η), where a non-zero asymmetry can be interpreted as an initial state interaction (related to the Sivers effect) or a final state correlation (partially related to the Collins effect). Transverse spin asymmetries have also been measured for muons from heavy flavored hadrons and J/Ψ, and are related to the gluon Sivers function. Some of these asymmetries have also been measured in proton-ion collision allowing the study of nuclear dependence. Unexpected large asymmetries have been found and will be discussed.
Finally, the status of the Drell-Yan transverse spin asymmetry analysis will be presented. The latter aims at measuring the Sivers function, and compare it to semi-inclusive measurements. It is a unique check of the universality of Transverse Momentum Distributions and will improve our understanding of initial/final state effects in spacelike versus timelike reactions.
