Related papers: Single spin asymmetry in $\pi p$ Drell-Yan process
The abundant production of lepton pairs via $J/\Psi$ creation at COMPASS, $\pi ^\pm \, p^\uparrow \to J/\Psi \, X \to \ell^+ \ell^- X$, allows a measurement of the transverse Single Spin Asymmetry generated by the Sivers effect. The crucial…
We derive the single-spin-dependent cross section for the Drell-Yan lepton-pair production and the direct-photon production in the $pp$-collision induced by the twist-3 three-gluon correlation functions in the transversely polarized nucleon…
Single-spin asymmetries were investigated in inclusive electroproduction of charged pions and kaons from transversely polarized protons at the HERMES experiment. The asymmetries were studied as a function of the azimuthal angle $\psi$ about…
Cross section formulas for the single spin asymmetry in $p^\uparrow p\to \pi(\ell_T)X$ and $e p^\uparrow \to \pi(\ell_T)X$ are derived and its characteristic features are discussed.
We consider single-inclusive forward pion production in high-energy proton-proton collisions at RHIC energies. A good baseline description of the transverse momentum distributions at high rapidity is obtained within Mueller's dipole…
We consider the leading twist $T$-odd contributions as the dominant source of the $\cos 2\phi$ azimuthal asymmetry in unpolarized $p\bar{p}\to \mu\mu^+ X$ dilepton production in Drell-Yan Scattering. This asymmetry contains information on…
We show that initial-state interactions contribute to the $\cos 2 \phi$ distribution in unpolarized Drell-Yan lepton pair production $p p$ and $ p \bar p \to \ell^+ \ell^- X$, without suppression. The asymmetry is expressed as a product of…
We calculate, in a model, the beam spin asymmetry in semi-inclusive jet production in deep inelastic scattering. This twist-3, $T$-odd observable is non-zero due to final state strong interactions. With reasonable choices for the…
We report on a recent investigation of the single spin asymmetry (SSA) in low virtuality electroproduction of $J/\psi$ in color evaporation model. We show that this can be used as a probe for the still unknown gluon Sivers function.
A consistent phenomenological approach to the computation of transverse single spin asymmetries in inclusive hadron production is presented, based on the assumed generalization of the QCD factorization theorem to the case in which quark…
We calculate the double spin asymmetry A_LL(x, y, z, P_hT) of pi^0 production with the spectator model and the model based on the factorization ansatz. We also calculate the double spin asymmetry for the integration over the range of…
We extract the Boer-Mulders functions for the proton by combining the unpolarized pd and pp Drell-Yan data measured by the E866/NuSea Collaboration by the assumption that the $\cos 2\phi$ asymmetry is from the Boer-Mulders function. Using…
Large transverse single spin asymmetries (SSA) were measured for pions produced in pp-collisions up to RHIC energies. Sizeable SSA were also found in semi-inclusive deep inelastic scattering (SIDIS). Theory can explain such spin effects by…
We extend our analysis of transverse single spin asymmetry (SSA) in electroproduction of $J/\psi$ to include the effect of the scale evolution of the transverse momentum dependent (TMD) parton distribution functions and gluon Sivers…
The COMPASS Collaboration at CERN has measured the transverse spin azimuthal asymmetry of charged hadrons produced in semi-inclusive deep inelastic scattering using a 160 GeV positive muon beam and a transversely polarised NH_3 target. The…
We extract the Boer-Mulders functions of valence and sea quarks in the proton from unpolarized $p+D$ Drell-Yan data measured by the FNAL E866 Collaboration. Using these Boer-Mulders functions, we calculate the $\cos 2 \phi$ asymmetries in…
The paper calculates the helicity-dependent dihadron fragmentation function (DiFF), by extending the dihadron spectator model and examine the single longitudinal spin asymmetry $A^{\sin(2\phi_h)}_{UL}$ from dihadron in semi-inclusive…
The STAR Collaboration reports a measurement of the transverse single-spin asymmetries, $A_{N}$, for neutral pions produced in polarized proton collisions with protons ($pp$), with aluminum nuclei ($p\rm{Al}$) and with gold nuclei…
By measuring transverse single spin asymmetries one has access to the transversity distribution function $\Delta_T q(x)$ and the transverse momentum dependent Sivers function $q_0^T(x,\vec{k}_T)$. New measurements from identified hadrons…
The measurement of transverse single spin asymmetries ($A_N$) provides insight into the structure of the nucleon. Several mechanisms have been proposed that attempt to explain $A_N$ based on QCD, and additional measurements of $A_N$ for…