相关论文: Constraining the polarized gluon PDF in pp collisi…
One of the primary goals of the spin program at the Relativistic Heavy Ion Collider (RHIC) is to determine the polarization of the sea quarks and gluons in the proton. The polarization of the sea quarks is probed through the production of…
We study the production of $W^{\pm}$ and $Z$ gauge bosons in proton-proton and proton-neutron collisions up to a center-of-mass energy $\sqrt s=0.5\ TeV$, in connection with the realistic possibility of having proton-deuteron collisions at…
A major goal of the RHIC spin program is to measure \Delta g, the gluon contribution to the proton's spin. Measurements by PHENIX of the double longitudinal spin asymmetry, A_LL, of the neutral pion production at mid-rapidity in polarized…
Our present information on the gluon polarisation Delta g/g is reviewed. The data from fixed-target lepton-nucleon experiments are in context with the recent data from the RHIC polarised pp collider. The main tools to study Delta g/g in…
In late 2001 the first polarized proton collisions at the Relativistic Heavy Ion Collider (RHIC) took place. The PHENIX experiment at RHIC has a broad program to investigate the spin structure of the proton. This program will be described,…
The distribution of the spin of the nucleon among its constituents can be parametrized in the form of polarized parton distribution functions for quarks and gluons. Using all available data on the polarized structure function $g_1(x,Q^2)$,…
At RHIC kinematics, polarized jet hadroproduction is dominated by $gg$ and $qg$ scattering, making the jet longitudinal double-spin asymmetry, $A_{LL}$, sensitive to gluon polarization in the nucleon. I will present STAR results of $A_{LL}$…
The proposal to perform polarized proton-proton collisions at collider energies at RHIC is reviewed. After a brief reminder of the desirability of high energy spin physics measurements, we discuss the machine parameters and detector…
STAR collected data in proton-proton collisions at sqrt(s)=200 GeV with transverse and longitudinal beam polarizations during the initial running periods in 2002--2004 at the Relativistic Heavy Ion Collider at Brookhaven National…
PHENIX has a well defined program for measuring the polarized gluon distribution in the nucleon. We measure the gluon polarization in the proton with polarized $p$-$p$ collisions at PHENIX. The measurements of gluon polarization $via$ the…
The production of jets in polarized proton collisions at STAR is dominated by quark-gluon and gluon-gluon scattering processes. The dijet longitudinal double-spin asymmetry $(A_{LL})$ is sensitive to the helicity distributions and may be…
The recent high precision SMC data on polarized $\mu p$ scatterings have again confirmed that very little of the proton spin is carried by quarks. To unravel the mystery of the proton spin structure, it is quite important to know the…
The double-helicity asymmetries ($A_{LL}$) of $\pi^{+}$ and $\pi^{-}$ production in polarized proton proton collisions are specially interesting probes of the gluon's polarization. Relative differences among $A_{LL}$ of positive, neutral,…
The proton is a composite object with spin one-half, understood to contain highly relativistic spin one-half quarks exchanging spin-one gluons, each possibly with significant orbital angular momenta. While their fundamental interactions are…
QCD motivated polarized parton distributions, evolved directly in $x$-space, are used to predict rates for prompt photon production at RHIC centre of mass energies. Various scenarios for the polarized gluon distributions are considered and…
The STAR experiment at RHIC measures the longitudinal double-spin asymmetry $A_{LL}$ for a variety of final states in collisions of longitudinally polarized protons to constrain the polarized gluon distribution in the proton. Asymmetries…
The longitudinally polarized gluon density is probed sensitively in hard collisions of polarized protons under the condition that the dominant dynamics are perturbative and of leading twist origin. First data have recently been presented by…
This paper contains three parts relating to the nucleon spin structure in a simple picture of the nucleon: (i) The polarized gluon distribution in the proton is dynamically predicted starting from a low scale by using a nonlinear QCD…
We compare constraints on the gluon polarization in the nucleon obtained in next to leading order global QCD fits to polarized deep inelastic scattering data with those coming from observables more directly linked to the gluon polarization,…
Production of W bosons in longitudinally polarized pp collisions provides an excellent tool to probe the flavor-dependence of sea quark polarizations in the polarized proton. Current status and future plans for the W physics program with…