Hadron Structure Functions within a Chiral Quark Model

We outline a consistent regularization procedure to compute hadron structure functions within bosonized chiral quark models. We impose the Pauli--Villars scheme, which reproduces the chiral anomaly, to regularize the bosonized action. We derive the Compton amplitude from this action and utilize the Bjorken limit to extract structure functions that are consistent with the scaling laws and sum rules of deep inelastic scattering.Comment: Talk prepared for the QNP 2000 conference in Adelaide Feb. 2000 and to appear in the proceedings. Presentation prevented by United Airlines. Four pages, uses esppre.sty which is include

Final State Interactions, T-odd PDFs & the Lensing Function

It has been suggested that under certain approximations the Sivers effect can be described in terms of factorization of final state interactions and a spatial distortion of impact parameter space parton distribution; that is a convolution of the so-called lensing function and the impact parameter GPD $E$. In this approach the lensing function is calculated in a non-perturbative eikonal model. This enables a comparison between the a priori distinct Sivers function and the GPD $E$ which goes beyond the discussion of overall signs.Comment: 5 pages, 5 figures, misprints corrected: To appear in the Proceedings of the 10th Conference on the Intersection of Particle and Nuclear Physics (CIPANP 2009) San Diego, CA, 25-31 May 200

Process dependence and spin asymmetries in hadronic reactions

We study transverse-spin asymmetries in single inclusive particle production hadronic scattering in terms of the generalized parton model (GPM)

Spectral analysis of gluonic pole matrix elements for fragmentation

The non-vanishing of gluonic pole matrix elements can explain the appearance of single spin asymmetries in high-energy scattering processes. We use a spectator framework approach to investigate the spectral properties of quark-quark-gluon correlators and use this to study gluonic pole matrix elements. Such matrix elements appear in principle both for distribution functions such as the Sivers function and fragmentation functions such as the Collins function. We find that for a large class of spectator models, the contribution of the gluonic pole matrix element in fragmentation functions vanishes. This outcome is important in the study of universality for fragmentation functions and confirms findings using a different approach.Comment: 9 pages, 4 figures, added reference