Related papers: Recent Results in Polarized Proton-Proton Elastic …
A significant sample of $p^{\uparrow}p\to p\pi^0 X$ events has been observed at STAR in $\sqrt{s}=200$ GeV transversely polarized $pp$ collisions, where an isolated $\pi^0$ is detected in the forward pseudorapidity range $2.65<\eta<3.9$…
The physics scope of polarized nucleon-nucleon collisions originating from an internal polarized target in the HERA proton beam is summarized. Based on 240 pb^{-1} integrated luminosity at 40 GeV c.m. energy, statistical sensitivities are…
We study the single-spin asymmetry, $A_N(t)$, arising from Coulomb-nuclear interference (CNI) at small 4-momentum transfer squared, $-t=q^2$, aiming at explanation of the recent data from the PHENIX experiment at RHIC on polarized…
The large values of the transverse single spin asymmetry, A_N, seen in forward pi0 production from polarized proton collisions have stimulated important questions and have been studied in QCD based transverse spin models. We report the…
Recent results on the use of hard probes in heavy ion collisions by the STAR experiment at RHIC are reviewed. The increased statistical reach from RHIC run 4 and utilization of the full capabilities of the STAR experiment have led to a…
A primary goal of the STAR Spin program at RHIC is the measurement of the polarized gluon distribution function $\Delta G$, which can be obtained from a global analysis incorporating measurements of the double spin asymmetry A_{LL} in…
The contribution to the spin of the proton from the gluon helicity is starting to come into focus: for gluons carrying a large fraction $x$ of the proton momentum, evidence of positive gluon polarization has been observed, via measurements…
The single transverse spin asymmetry in D meson production at RHIC can provide a clean measure of the gluon Sivers distribution function. At intermediate rapidity, D production is largely dominated by the elementary gg -> c c-bar channel,…
The flavor dependence of polarized and unpolarized quark distributions in the nucleon can lead to insights into the formation of the sea. Drell-Yan measurements have pointed to flavor asymmetries in the unpolarized distributions. Collisions…
Polarized protons have never been accelerated to more than about $25$GeV. To achieve polarized proton beams in RHIC (250GeV), HERA (820GeV), and the TEVATRON (900GeV), ideas and techniques new to accelerator physics are needed. In this…
We discuss a curious observation: at energies from the ISR and up to the LHC, inclusively, the differential cross-section of elastic proton-proton scattering remains almost energy-independent at the transferred momentum t =-0.21 GeV^2 at…
We report new STAR measurements of the single-spin asymmetries $A_L$ for $W^+$ and $W^-$ bosons produced in polarized proton--proton collisions at $\sqrt{s}$ = 510 GeV as a function of the decay-positron and decay-electron pseudorapidity.…
A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision…
The STAR Experiment at RHIC is well-suited to making measurements of particle yields from relativistic nuclear collisions in the low transverse momentum, or "soft", regime. We present preliminary results on measurements of pion (0,-,+),…
The document describes the physics case of the PAX experiment using polarized antiprotons, which has recently been proposed for the new Facility for Antiprotons and Ions Research (FAIR) at GSI--Darmstadt. Polarized antiprotons provide…
We consider longitudinal, parity-violating single-spin asymmetries in proton-proton collisions at RHIC. The focus of this study is on the production of single-inclusive jets, as well as on jets that contain a charm quark. While the…
We compare a few types of high energy reactions which seem to be practical for polarimetry at RHIC. Coulomb-nuclear interference (CNI) in pp elastic scattering leads to a nearly energy-independent left-right asymmetry A_N(t) at small t. The…
The related studies of two-particle correlations and event-by-event fluctuations have played important roles in the search for new physics through the experimental study of relativistic heavy ion collisions. We present a general method of…
One purpose of this meeting is to assess the physics potential of HERA-N Stage I. To develop a reasonable perspective, it is useful to look at other spin experiments. For completeness, this report discusses some of the single spin physics…
The method described in my RHIC Spin Note (hep-ph/305085) is applied to recently reported data from RHIC experiments in order to obtain values for the spin-flip Regge couplings. The data comes from both 100 GeV/c proton elastic scattering…