Related papers: Gluon Polarization in Longitudinally Polarized $pp…
We review the most important experimental results from the first three years of nucleus-nucleus collision studies at RHIC, with emphasis on results from the STAR experiment, and we assess their interpretation and comparison to theory. The…
Measurements of double helicity asymmetries for inclusive hadron production in polarized proton-proton collisions are sensitive to spin-dependent parton distribution functions, in particular to the gluon distribution, Delta g. This study…
Effects of the spin-dependent gluon distributions on J/$\psi$ productions in polarized ep and pp collisions are investigated. These productions serve as a very clean probe of the spin-dependent gluon distributions in a proton.
The polarized proton beams at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory provide a unique environment to observe hard scattering between gluons and quarks. The PHENIX experiment has recorded collisions at…
We report the first measurement of the parity violating single-spin asymmetries for midrapidity decay positrons and electrons from $W^{+}$ and $W^{-}$ boson production in longitudinally polarized proton-proton collisions at $\sqrt{s}=500…
We report a measurement of cumulants and correlation functions of event-by-event proton multiplicity distributions from fixed-target Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 3 GeV measured by the STAR experiment. Protons are identified…
The longitudinal double spin asymmetry A_LL in the reaction pp --> pi X has been measured at RHIC with extremely interesting consequences. If the gluon polarization in a proton were as big as needed to resolve the famous "spin crisis" then…
Measurements by the STAR collaboration of neutral pion production at large Feynman $x$ ($x_F$) in the first polarized proton collisions at $\sqrt{s}=200$ GeV were reported previously. During the following two runs additional statistics were…
Single-spin asymmetry appears due to the interference of single and double gluon exchange between protons. A heavy fermion model is used to describe the jet production in the interaction of gluon with the proton implying the further…
These proceeding present recent measurements by the STAR Collaboration of jet production in p+p and Au+Au collisions at sqrt(sNN) = 200 GeV. We focus on jet yields, substructure, and heavy-flavor production, and their modification in the…
Over the past several years the STAR experiment at RHIC has been contributing to our understanding of the proton structure. Through its instrumentation, STAR is well equipped to measure $W \rightarrow \nu + e$ in $\sqrt{s}$ = 500/510 GeV…
One of the key objectives of the COMPASS experiment at CERN is the determination of the gluon contribution to the nucleon spin. The gluon polarization is measured via photon-gluon fusion in deep-inelastic scattering of 160 GeV/c polarized…
We study photoproduction of jets and heavy flavors in a polarized collider mode of HERA at $\sqrt{S}= 298$ GeV. We examine the sensitivity of the cross sections and their asymmetries to the proton's polarized gluon distribution and to the…
We calculate the cross section and single-spin azimuthal asymmetry, A_n(t) for inclusive neutron production in pp collisions at forward rapidities relative to the polarized proton. Absorptive corrections to the pion pole generate a relative…
We report the first measurement of one- and two-point energy correlators within jets in transversely polarized proton-proton collisions at $\sqrt{s}=200$ GeV, using the STAR detector at RHIC. These observables quantify the energy-weighted…
The predicted quenching of jets in A+A at RHIC energies has been discovered by STAR and PHENIX in preliminary data reported at this conference. We apply the GLV theory of QCD radiative energy loss to estimate the opacity, L/\lambda_g, of…
Within the collinear twist-3 framework, we analyze the double-spin asymmetry in collisions between longitudinally polarized nucleons and transversely polarized nucleons with focus on hadron and jet production. As was the case in direct…
We study the azimuthal $\cos \varphi$ and $\cos 2\varphi$ asymmetries in heavy-quark pair leptoproduction, $lN\rightarrow l^{\prime}Q\bar{Q}X$, as probes of linearly polarized gluons inside unpolarized proton, where the azimuth $\varphi$ is…
Within a generalized parton model approach, with inclusion of spin and intrinsic transverse momentum effects, we show how the latest, highly precise, midrapidity data on the transverse single spin asymmetry measured in $pp\to\pi^0\, X$ by…
Measurements of strangeness production in jets help illuminate the QCD mechanisms in fragmentation. Furthermore, they provide a crucial baseline for heavy-ion studies where modifications in jet chemistry have recently been predicted. We…