The Chiral Odd Nucleon Tensor Charge

Exploiting the phenomenological symmetry of the $J^{PC}=1^{+-}$ light axial vector mesons and using pole dominance, we calculate the flavor contributions to the nucleon tensor charge.Comment: 6 pages LaTeX with ws-p8-50x6-00.cls (included). To appear in the proceedings of the 6th workshop on non-perturbative QCD, Paris, June 200

Flavor-Spin Symmetry Estimate of the Nucleon Tensor Charge

The axial vector and tensor charge, defined as the first moments of the forward nucleon matrix elements of corresponding quark currents, are essential for characterizing the spin structure of the nucleon. However, the transversity distribution and thus the tensor charge decouple at leading twist in deep inelastic scattering, making them hard to measure. Additionally, the non-conservation of the tensor charge makes it difficult to predict. There are no definitive theoretical predictions for the tensor charge, aside from several model dependent calculations. We present a new approach that exploits the approximate mass degeneracy of the light axial vector mesons ($a_1$(1260), $b_1$(1235) and $h_1$(1170)) and uses pole dominance to calculate the tensor charge. The result is simple in form. It depends on the decay constants of the axial vector mesons and their couplings to the nucleons, along with the average transverse momentum of the quarks in the nucleon.Comment: 4 pages, RevTe

Transversity Properties of Quarks and Hadrons in SIDIS and Drell-Yan

We consider the leading twist $T$-odd contributions as the dominant source of the azimuthal and transverse single spin asymmetries in SIDIS and dilepton production in Drell-Yan Scattering. These asymmetries contain information on the distribution of quark transverse spin in (un)polarized protons. In the spectator framework we estimate these asymmetries at HERMES kinematics and at $50\ {\rm GeV}$ for the proposed experiments at GSI, where an anti-proton beam is ideal for studying the transversity properties of quarks due to the dominance of {\em valence} quark effects.Comment: 4 pages, 8 figures. To appear in the proceedings of the XIII International Workshop on Deep Inelastic Scattering (DIS 2005, Madison

Flavor-Spin Symmetry and the Tensor Charge

Exploiting an approximate phenomenological symmetry of the $J^{PC}=1^{+-}$ light axial vector mesons and using pole dominance, we calculate the flavor contributions to the nucleon tensor charge. The result depends on the decay constants of the axial vector mesons and their couplings to the nucleons.Comment: Talk given at 3rd Circum-Pan-Pacific Symposium on High Energy Spin Physics (SPIN 2001), Beijing, China, 8-13 Oct 200

Novel Transversity Properties in SIDIS

We consider a rescattering mechanism to calculate a leading twist $T$-odd pion fragmentation function, a candidate for filtering the transversity properties of the nucleon. We evaluate the single spin azimuthal asymmetry for a transversely polarized target in semi-inclusive deep inelastic scattering (for HERMES kinematics) and the double $T$-odd $\cos2\phi$ asymmetry in this framework.Comment: To appear in the proceedings of 8th Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2003), New York, New York, 19-24 May 200

Novel Azimuthal Asymmetries in Drell Yan and Semi-inclusive Deep Inelastic Scattering

We consider the leading and sub-leading twist $T$-odd and even contributions to the $\cos 2\phi$ azimuthal asymmetry in unpolarized dilepton production in Drell-Yan Scattering. We estimate the contributions' effects at $500 {\rm GeV}$, $50 {\rm GeV}$, and $25 {\rm GeV}$ energies in the framework of the parton model using a quark diquark-spectator model of the nucleon to approximate the soft contributions.Comment: 6 pages, 4 figure