Related papers: Transverse-Spin and Transverse-Momentum Effects in…
Recently, it has been shown, contrary to previous beliefs, that the k_T distribution of quarks in a transversely polarized proton can be asymmetric. This ``Sivers effect'' had already been used to explain transverse single spin asymmetries…
We investigate leading twist transverse momentum dependent origins of transverse spin asymmetries in hadron-hadron collisions. The chiral-odd T-odd distribution function with intrinsic transverse momentum dependence, which would signal an…
Semi-Inclusive Deep-Inelastic Scattering provides unique access to the three-dimensional momentum and spin structure of the proton, enabling precise studies of parton dynamics and hadronization in QCD. We present a transverse-momentum…
Exclusive hadronic reactions with a massive lepton pair (l^+l^-) in the final state will be measured with PANDA at GSI-FAIR and with Compass at CERN, both in p+p-bar -> l^+l^-+pi and pi+N -> N'+l^+l^-. Similarly, electroproduction of a…
It is pointed out that the existing models for the left-right asymmetries observed in single-spin inclusive hadron production processes can be differentiated experimentally. Several such experiments are proposed with which the basic…
Transverse single spin asymmetries of particles produced in $p+p^{\uparrow}$ collisions provide insight on the partonic spin and momentum structure of hadrons; heavy flavor electrons provide access to initial state spin-momentum…
We consider theoretical background for experimental measurements of single-spin asymmetries. We stress the non-perturbative QCD aspects of observed asymmetries in hadronic reactions.
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…
A quantitative estimate is presented for the double transverse spin asymmetries at measured q_T in both the Drell-Yan process and W-boson production due to Transverse Momentum Dependent (TMD) effects. These spin asymmetries are calculated…
We discuss the prospects to observe effects of transverse polarization and spin-spin correlations of top quark pairs produced at hadron colliders.
We discuss transverse spin effects caused by the spin-flip part of the Pomeron coupling with the proton. The predicted spin asymmetries in proton-proton scattering and QQ production in proton-proton and lepton-proton reactions are not small…
Measurements of single transverse spin asymmetries in high energy inclusive processes have always shown unexpected and challenging results. Several cases are considered and discussed within a QCD approach which couples perturbative dynamics…
The investigation of transverse spin and transverse momentum effects in deep inelastic scattering is one of the key physics programs of the COMPASS collaboration. In the years 2002-2004 COMPASS took data scattering 160 GeV muons on a…
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 point out that measuring longitudinal polarizations of different hyperons produced in lepton induced reactions are ideal to study the spin transfer of the fragtmenting quark to produced hadron in high energy hadronization processes. We…
Single-spin asymmetries for pions and charged kaons are measured in semi-inclusive deep-inelastic scattering of positrons and electrons off a transversely nuclear-polarized hydrogen target. The dependence of the cross section on the…
The inclusive large-$p_T$ production of a single pion, jet or direct photon, and Drell-Yan processes, are considered for proton-proton collisions in the kinematical range expected for the fixed-target experiment AFTER, proposed at LHC. For…
We discuss various azimuthal asymmetries in semi-inclusive DIS and e^+e^- ==> h1 h2 X which involve chiral odd quantities like the transversity distribution h_1 and a fragmentation function H_1^\perp. For the fragmentation described by…
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…
The investigation of transverse spin and transverse momentum effects in deep inelastic scattering is one of the key physics programs of the COMPASS collaboration. In the years 2002-2004 COMPASS took data scattering 160 GeV muons on a…