Related papers: Spin Effects in Diffractive $Q \bar Q$ Production …
We report a measurement of the longitudinal double-spin asymmetry A_LL and the differential cross section for inclusive Pi0 production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV. The cross section was measured over a…
In this paper we study the double longitudinal spin asymmetry of dihadron production in semi-inclusive deep inelastic scattering (SIDIS). We calculate a unknown twist-3 dihadron fragmentation function $\widetilde{D}^\sphericalangle$ within…
HERMES is a second generation experiment to study the spin structure of the nucleon, in which measurements of the spin dependent properties of semi-inclusive deep-inelastic lepton scattering are emphasized. Data have been accumulated for…
We propose to measure the threshold lepton asymmetry, that is the forward-backward asymmetry of the charged lepton in ttbar events near the production threshold. At threshold top quark pairs are produced in an s-wave. Angular momentum…
We study the single-transverse spin asymmetry for the Drell-Yan process. We consider production of the lepton pair at large transverse momentum, $q_\perp\sim Q$, where $Q$ is the pair's mass. The spin asymmetry is then of higher twist and…
Electromagnetic dipole interactions of light quarks induce distinct spin correlations in quark pairs produced at lepton colliders, favoring entangled spin-triplet state aligned along the $\hat{z}$ axis or spin-singlet state. These…
We calculate the single spin asymmetry in the inclusive pion production in proton-proton collisions. We generate the asymmetry at the level of fragmentation function (Collins effect) by the Lund coloured string mechanism. We compare our…
One of the important objectives of the COMPASS experiment (SPS, CERN) \cite{Abbon:2007pq} is the exploration of the transverse spin structure of the nucleon via spin dependent azimuthal asymmetries in single-hadron production in deep…
This contribution reports on the first measurement of the longitudinal double-spin asymmetry $A_{LL}$ for the inclusive production of jets in polarized proton-proton collisions at $\sqrt{s}=200 \mathrm{GeV}$. The data were collected with…
We have presented the results for the single and double spin asymmetries in semi-inclusive deep inelastic scatterings for proton in a light front quark-diquark model. The asymmetries generated by the T-even TMDs are discussed here. The…
It is shown that the existence of left-right asymmetry in single-spin inclusive Lambda production, together with the characteristic features of the data, should be considered as another clear signature for the existence of orbiting valence…
We study the semi-inclusive production of real, high-$p_T$, isolated photons in unpolarized and polarized lepton-proton collisions, $\ell p\to \ell\gamma X$. In particular we analyze the transverse nucleon single-spin asymmetry within the…
Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle phi of the pion relative to the…
We calculate the contribution of meson and pomeron exchanges to the double-spin asymmetry in $\rho$-meson electromagnetic production at HERMES energies. We show that the observed double-spin asymmetries, which are large, can be explained by…
Double-spin asymmetries in the cross section of electroproduction of $\rho^0$ and $\phi$ mesons on the proton and deuteron are measured at the HERMES experiment. The photoabsorption asymmetry in exclusive $\rho^0$ electroproduction on the…
The spin structure of the proton is investigated in the framework of an extended quark potential model which in addition to the conventional $3q$--structure also takes into account $(3q)(q\bar q)$--admixtures in the proton wave function.…
A comprehensive set of azimuthal single-spin and double-spin asymmetries in semi-inclusive leptoproduction of pions, charged kaons, protons, and antiprotons from transversely polarized protons is presented. These asymmetries include the…
In this review a first comprehensive study of azimuthal asymmetries in semi-inclusive deep inelastic muoproduction of hadron pairs off longitudinally polarized protons at COMPASS is presented. The study is based on data taken in 2007 and…
We report new STAR measurements of the single-spin asymmetries $A_L$ for $W^+$ and $W^-$ bosons produced in polarized proton--proton collisions at $\sqrt{s}$ = 510 GeV as a function of the decay-positron and decay-electron pseudorapidity.…
Predictions are made for single spin azimuthal asymmetries due to the Collins effect in pion production from semi-inclusive deeply inelastic scattering off transversely and longitudinally polarized targets for the HERMES and COMPASS…