Related papers: Spin effects in large rapidity pi0 production at S…
The STAR collaboration has reported precision measurements on the transverse single spin asymmetries for the production of forward $\pi^0$ mesons from polarized proton collisions at $\sqrt{s} =\,$200 GeV. To disentangle the contributions to…
Measurements of the longitudinal double-spin asymmetry, $A_{LL}$, by the STAR experiment have contributed significantly to our understanding of the gluon helicity distribution, $\Delta g(x)$, inside the proton. Results from the 2009…
In Spiring 2005, RHIC successfully completed its first long data collection run with polarized proton beams. PHENIX accumulated ten fold larger statistics with higher polarization than the previous spin physics run in 2003. This…
In June 2005 the PHOBOS Collaboration completed data taking at RHIC. In five years of operation PHOBOS recorded information for Au+Au at $\sqrt{s_{NN}}$ = 19.6, 62.4, 130, and 200 GeV, Cu+Cu at 22.4, 62.4 and 200 GeV, d+Au at 201 GeV, and…
We report the first measurement of transverse single-spin asymmetries in $J/\psi$ production from transversely polarized $p+p$ collisions at $\sqrt{s} = 200$ GeV with data taken by the PHENIX experiment in 2006 and 2008. The measurement was…
Understanding the internal spin structure of the nucleon still remains a challenge in strong interaction physics. Transversity, which describes the transverse spin structure of quarks in a transversely polarized proton, is poorly…
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…
The spin structure functions of the proton and the deuteron were measured during the EG4 experiment at Jefferson Lab in 2006. Data were collected for longitudinally polarized electron scattering off longitudinally polarized NH$_3$ and…
Transverse single spin asymmetry, $A_{N}$, of very forward $\pi^{0}$ production from polarized $p + p$ collisions provides new information toward an understanding of its production mechanism. $A_{N}$ of forward $\pi^{0}$ in the…
The measurement of the central exclusive production of charged hadron pairs $h^{+}h^{-}$ ($h = \pi, K, p$) by the STAR experiment at RHIC is reported. The data from proton-proton collisions at $\sqrt{s} = 200$ GeV were used in this study.…
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…
We present preliminary results for the first measurements of the double longitudinal spin asymmetry A_LL in inclusive jet production at mid-rapidity in polarized proton-proton collisions at sqrt(s) = 200 GeV. The data amount to ~ 0.5 pb-1…
The PHENIX experiment at the Relativistic Heavy Ion Collider has measured the longitudinal double spin asymmetries, $A_{LL}$, for charged pions at midrapidity ($|\eta|<0.35$) in longitudinally polarized $p$$+$$p$ collisions at…
One of the primary goals of the RHIC Spin program is to determine the gluon polarization distribution within the proton. At leading order, $pp$ collisions involve a mixture of quark-quark, quark-gluon, and gluon-gluon scattering. In RHIC,…
In 2015, the PHENIX collaboration has measured single-spin asymmetries for charged pions in transversely polarized proton-proton collisions at the center of mass energy of $\sqrt{s}=200$ GeV. The pions were detected at central rapidities of…
The Relativistic Heavy Ion Collider (RHIC) has brought the study of spin effects in hadronic collisions to a new energy regime. In conjunction with other experiments at facilities around the world, much can be learned from the high-energy…
I report on results from the PHENIX collaboration for the first RHIC run, where gold ions were collided at $\sqrt{s_{NN}}=130 GeV$. In order to study initial conditions, PHENIX has measured the ratio between anti-protons and protons, the…
The double helicity asymmetry in neutral pion production for p_T = 1 to 12 GeV/c has been measured with the PHENIX experiment in order to access the gluon spin contribution, Delta-G, to the proton spin. Measured asymmetries are consistent…
The invariant differential cross section for inclusive neutral pion production in p+p collisions at sqrt(s_NN) = 200 GeV has been measured at mid-rapidity |eta| < 0.35 over the range 1 < p_T <~ 14 GeV/c by the PHENIX experiment at RHIC.…
The physics goals that will be addressed by colliding polarized protons at the Relativistic Heavy Ion Collider (RHIC) are described. The RHIC spin program provides a new generation of experiments that will unfold the quark, anti-quark and…