2017/03/16 by Zhang, Jinlong
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)
paper · doi:10.48550/arxiv.1703.05816
The production of W^± bosons in longitudinally polarized p+p collisions at RHIC provides a direct probe for the spin-flavor structure of the proton through the parity-violating single-spin asymmetry, AL. At STAR, the leptonic decay channel W → eν can be measured with the electromagnetic calorimeters and time projection chamber. STAR has previously measured AL as a function of the decay electron and decay positron pseudorapidities from datasets taken in 2011 and 2012. This has provided significant constraints on the u and d quark helicity distributions. In 2013 the STAR experiment collected an integrated luminosity of ∼300 pb-1 at √(s)=510 GeV with an average beam polarization of ∼56%, which is more than three times larger than the total integrated luminosity of previous years. The new preliminary results of the W AL analysis for the dataset collected in 2013 are reported.