Related papers: Inclusive $A_{LL}$ Measurements at STAR
We evaluate the azimuthal asymmetries for the distributions of leading pions inside a jet, produced in high-energy proton-proton collisions, in kinematic configurations currently under active investigation at RHIC. Adopting a transverse…
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,…
The STAR experiment at the Relativistic Heavy Ion Collider RHIC studies the new state of matter produced in relativistic heavy ion collisions and the spin structure of the nucleon in collisions of polarized protons. In order to improve the…
We compute the next-to-leading order QCD corrections to the spin-independent and spin-dependent cross-sections for the production of a single-hadron accompanied by an opposite jet in hadronic collisions. This process is being studied…
Hadroproductions of charmonium and bottomonium $\chi_J$ in polarized $pp$ collisions at RHIC energies are studied. Two--spin asymmetries $A_{LL}^{\chi_J}(pp)$ for these reactions are very good parameters for examining the polarized gluon…
The PHENIX experiment has measured transverse single spin asymmetry of J/$\Psi$ in polarized p+p collisions at forward rapidity at $\sqrt{s}=200$ GeV. The data were collected from year 2006 run of RHIC with average beam polarization of 56%.…
Jets are collimated clusters of particles formed by the hadronization of partons following a hard interaction. In proton-proton ($pp$) collisions at the Relativistic Heavy Ion Collider (RHIC), jet production is dominated by $gg$ and $qg$…
PHENIX measurements are presented for the cross section and double-helicity asymmetry ($A_{LL}$) in inclusive $\pi^0$ production at midrapidity from $p$$+$$p$ collisions at $\sqrt{s}=510$~GeV from data taken in 2012 and 2013 at the…
Around 1999, thanks to the RHIC Spin Collaboration (RSC), the Relativistic Heavy Ion Collider (RHIC) will be used as a polarized proton-proton collider. A new handed interaction between quark subconstituents, which could explain the excess…
First measurements of large Feynman x (x_F) neutral pion production in polarized proton collisions at sqrt(s)=200 GeV were reported previously. Cross section measurements at <eta>=3.3 and 3.8$ and analyzing power (A_N) measurements at…
We present a detailed assessment of how well a future Electron-Ion Collider could constrain helicity parton distributions in the nucleon and, therefore, unveil the role of the intrinsic spin of quarks and gluons in the proton's spin budget.…
The origins of the proton spin remain an area of active investigation. The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab uniquely provides polarized proton data at high center of mass energies. STAR has previously…
We explore the possibility of measuring nuclear gluon distributions at the Relativistic Heavy-Ion Collider (RHIC) with $\sqrt{s}=200 \, {\rm GeV}$ proton-nucleus collisions. In addition to measurements at central rapidity, we consider also…
We consider the inclusive production of longitudinally polarized baryons in ${\vec p}p$ collisions at RHIC-BNL, with one longitudinally polarized proton. We study the spin transfer between the initial proton and the produced baryon as a…
A new handed interaction between quarks could be at the origin of some small parity violating effects in the inclusive production of one-jet in polarized $pp$ collisions. This interaction could originate from compositeness or from the…
The RHIC spin program will probe the spin structure of the proton with polarized quarks and gluons by colliding beams of polarized protons at Brookhaven. The first collisions, at sqrt(s)=200GeV, were recorded this year in December 2001 and…
The gamma +jet production in p(->)-p(->) collisions at high energies is studied. Double-spin asymmetry A{LL} of the process is calculated by using Monte Carlo code SPHINX. The predictions for A{LL} of the gamma +jet production in the…
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 presents double helicity asymmetry in inclusive $\pi^0$ production in polarized proton-proton collisions at a center-of-mass energy ($\sqrt{s}$) of 200 GeV. The data were collected with the PHENIX detector at the Relativistic…
Since the first surprising results on the spin structure of the proton by the EMC experiment in the late 1980s, much progress has been made in understanding the origin of the proton spin. However, the sea quark contribution to the proton…