Fluctuation and flow probes of early-time correlations in relativistic heavy ion collisions

Fluctuation and correlation observables are often measured using multi-particle correlation methods and therefore mutually probe the origins of genuine correlations present in multi-particle distribution functions. We investigate the common influence of correlations arising from the spatially inhomogeneous initial state on multiplicity and momentum fluctuations as well as flow fluctuations. Although these observables reflect different aspects of the initial state, taken together, they can constrain a correlation scale set at the earliest moments of the collision. We calculate both the correlation scale in an initial stage Glasma flux tube picture and the modification to these correlations from later stage hydrodynamic flow and find quantitative agreement with experimental measurements over a range of collision systems and energies.Comment: Proceedings of the 28th Winter Workshop on Nuclear Dynamics, Dorado del Mar, Puerto Rico, April 7-14, 201

Longitudinal and transverse spin asymmetries for inclusive jet production at mid-rapidity in polarized p+p collisions at √s=200 GeV

We report STAR measurements of the longitudinal double-spin asymmetry ALL, the transverse single-spin asymmetry AN, and the transverse double-spin asymmetries AΣ and ATT for inclusive jet production at mid-rapidity in polarized p+p collisions at a center- of-mass energy of √s=200  GeV. The data represent integrated luminosities of 7.6  pb-1 with longitudinal polarization and 1.8  pb- 1 with transverse polarization, with 50%–55% beam polarization, and were recorded in 2005 and 2006. No evidence is found for the existence of statistically significant jet AN, AΣ, or ATT at mid- rapidity. Recent model calculations indicate the AN results may provide new limits on the gluon Sivers distribution in the proton. The asymmetry ALL significantly improves the knowledge of gluon polarization in the nucleon

Transverse single-spin asymmetry and cross section for π0 and η mesons at large Feynman x in p↑+p collisions at √s=200 GeV

Measurements of the differential cross section and the transverse single-spin asymmetry, AN, vs xF for π0 and η mesons are reported for 0.40.55, is consistent with a perturbative QCD prediction, and the η/π0 cross-section ratio agrees with existing midrapidity measurements. For 0.5