相关论文: Probing Sea Quark and Gluon Polarization at STAR
We report STAR's preliminary measurement of the inclusive jet longitudinal spin asymmetry $A_{LL}$ using data from the RHIC 2006 run. The 2006 data set was taken with 200 GeV polarized proton-proton collisions and represents 4.7 $pb^{-1}$…
The STAR Collaboration reports precise measurements of the longitudinal double-spin asymmetry, $A_{LL}$, for dijet production with at least one jet at intermediate pseudorapidity $0.8 < \eta_{\rm jet} < 1.8$ in polarized proton-proton…
Understanding the origin of the proton spin is one of the most fundamental and challenging questions in QCD. Much progress has been made since the first surprising result by the EMC experiment in the late 1980s. However, the helicity…
We report the first measurements of transverse single-spin asymmetries for inclusive jet and jet + $\pi^{\pm}$ production at midrapidity from transversely polarized proton-proton collisions at $\sqrt{s} = 500$ GeV. The data were collected…
We report the measurement of the parity violating single spin asymmetries for inclusive high transverse momentum electrons and positrons in polarized $p+p$ collisions at a center of mass energy of $\sqrt{s}=500$ GeV with the PHENIX detector…
The PHENIX experiment presents results from the RHIC 2006 run with polarized proton collisions at sqrt(s) = 62.4 GeV for inclusive pi^0 production at mid-rapidity. Unpolarized cross section results are measured for transverse momenta p_T =…
We discuss the impact of recent high-statistics RHIC data on the determination of the gluon polarization in the proton in the context of a global QCD analysis of polarized parton distributions. We find clear evidence for a non-vanishing…
RHIC is the only spin-polarized proton collider ever built. With a special optics run of $\beta^\star \approx 22$ m STAR detector system is suitable for an investigation of the spin dependence of elastic proton-proton scattering. This is a…
The Polarized Atomic Hydrogen Gas Jet Target polarimeter is employed by the Relativistic Heavy Ion Collider (RHIC) to measure the absolute polarization of each colliding proton beam. Polarimeter detectors and data acquisition were upgraded…
We present the first simultaneous global QCD analysis of spin-dependent parton distribution functions alongside their spin-averaged counterparts and pion, kaon, and unidentified hadron fragmentation functions. This analysis includes all…
The advantage and feasibility of using $W$-boson production to extract unique information on the flavor asymmetry of the $\bar u$ and $\bar d$ sea-quark distributions in the proton are examined. The $W^+$ and $W^-$ production cross section…
The parity-violating asymmetry is an ideal tool to study the quark helicity distribution in the proton. We study the parity-violating asymmetry of $W^{\pm}$ bosons produced by longitudinally polarized $p$-$p$ collision in RHIC, based on…
We study the charge asymmetry between the $t$ and $\bar t$ quark at the LHC, when they are produced in association with a $W$ boson. Though sizably reducing the cross section with respect to the inclusive production, requiring a $W$ boson…
We show that the production of a Higgs boson in association with a jet in proton-proton collisions is sensitive to the linear polarization of gluons inside unpolarized protons. We present the analytical expressions, at leading order in…
The RHIC facility at BNL will be operating soon, part of the year, as a polarized proton-proton collider. This will allow the undertaking of a vast spin physics programme, mainly by the two large detectors PHENIX and STAR. We review some…
We present a comprehensive impact study of future Electron-Ion Collider (EIC) data for parity-conserving and parity-violating polarization asymmetries on quark and gluon helicity distributions in the proton. The study, which is based on the…
The double spin asymmetry for exclusive $J/\psi$ pair production in the polarized $p-p$ collisions at RHIC is investigated. Our study shows that the asymmetry in this process is measurable at RHIC-SPIN experiments in the near future, and,…
Our recent study shows that the double spin asymmetry of J/\psi pair production is measurable in polarised p-p collision at RHIC in near future. And hence it enables us to extract the polarised gluon distribution function \Delta G (x).
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…
This report is based on a ten-week program on "Gluons and the quark sea at high-energies", which took place at the Institute for Nuclear Theory in Seattle in Fall 2010. The principal aim of the program was to develop and sharpen the science…