Related papers: Double Spin Asymmetries in Charmonium Hadroproduct…
We discuss the double spin asymmetries in P-wave charmonium hadroproduction with non-zero transverse momenta at fixed target energies, $\sqrt{s}\simeq40$ GeV, within the framework of the NRQCD factorization approach. The size of the…
We calculated the color-octet contribution to the double spin asymmetry of $J/\psi$ hadroproduction with nonzero transverse momenta at fixed target energies $\sqrt{s}\simeq40$ GeV. It is shown that the color-octet contribution is dominant…
The physics scope of a possible future experiment utilizing an internal polarized nucleon target in the HERA proton beam is discussed. By measuring single spin asymmetries in inclusive particle production at 820~GeV beam energy the…
We studied the photoproduction of $\psi^{\prime}$ in the forward regions in polarized $\gamma p$ collisions at relevant HERA energies. We found that this reaction is very effective to test the color-octet mechanism which is based on the…
Within the framework of transverse momentum dependent factorization in combination with nonrelativistic QCD, we study charmonium and bottomonium production in hadronic collisions. We focus on quarkonium states with even charge conjugation,…
We report the measurement of beam-target double-spin asymmetries ($A_\text{LT}$) in the inclusive production of identified hadrons, $\vec{e}~$+$~^3\text{He}^{\uparrow}\rightarrow h+X$, using a longitudinally polarized 5.9 GeV electron beam…
We present a measurement of the longitudinal spin asymmetry A_|| in photoproduction of pairs of hadrons with high transverse momentum p_T. Data were accumulated by the HERMES experiment using a 27.5 GeV polarized positron beam and a…
We investigate the pattern of asymmetries in the colour-octet model for inclusive production of charmonium with polarised initial state hadrons and photons. We find that singly polarised asymmetries vanish. The double polarised asymmetry…
We consider double spin asymmetries for longitudinally polarized leptons and transversally polarized protons in diffractive vector meson and $Q \bar Q$ production for the HERMES energy range on the basis of the two-gluon model. The…
The spin correlation parameters, polarization - $A_{N}$ and double spin correlation parameters - $A_{NN}$, are calculated in the framework of dynamical model (GKS) of the hadron-hadron interection in the whole region of small angles and for…
The physics scope of polarized nucleon-nucleon collisions originating from an internal polarized target in the HERA proton beam is summarized. Based on 240 pb^{-1} integrated luminosity at 40 GeV c.m. energy, statistical sensitivities are…
Evidence for a positive longitudinal double-spin asymmetry <A_1^rho> = 0.24 +-0.11 (stat) +-0.02 (syst) in the cross section for exclusive diffractive rho^0(770) vector meson production in polarised lepton-proton scattering was observed by…
We present a NLO study of inclusive polarized prompt photon production in a conceivable fixed target $pp$ mode of HERA with longitudinally polarized protons at $\sqrt{s}=39$ GeV. We analyze the sensitivity of the corresponding double spin…
Hermes has measured longitudinal double spin asymmetries as a function of transverse momentum pT using charged inclusive hadrons from electroproduction off a deuterium target. At pT>1 GeV, the asymmetries are sensitive to the spin dependent…
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…
We study the beam single-spin asymmetries $A_{LU}^{\sin\phi_h}$ for charged hadrons produced in semi-inclusive deep inelastic scattering process, by considering the $e H_1^\perp$ term and the $g^\perp D_1$ term simultaneously. Besides the…
Longitudinal double-spin asymmetries of charged hadrons with high transverse momentum $p_T$ have been measured in electroproduction using the \hermes\ detector at \hera. Processes involving gluons in the nucleon have been enhanced relative…
We study all the possible spin asymmetries that can arise in back-to-back electron-jet production, $ep\rightarrow e+\text{jet}+X$, as well as the associated jet fragmentation process, $ep\rightarrow e+ \text{jet} (h)+X$, in electron-proton…
We consider double spin asymmetries for longitudinally polarized leptons and transversely polarized protons in diffractive vector meson and $Q \bar Q$ production at high energies within the two-gluon model. The asymmetry predicted for meson…
The study of two spin asymmetries in hadron-hadron collisions probes the details of fundamental particle interactions in ways infeasible to machines with unpolarized collisions. Within reach is how the proton spin is distributed among its…