Narrow Results

We argue that a Regge-pole modification of the VDM puts on equal footing the asymptotic behavior of electromagnetic and neutral vector meson currents.

A brief summary is reported on measurements of soft and hard diffractive processes by the ATLAS, CMS and TOTEM collaborations at a center of mass energy of 7 TeV.

In this work, the mass spectrum of the first radial excitation axial vector meson nonet is considered in the framework of the nonrelativistic constituent quark model and Regge phenomenology. After that, we investigate the strong decay characteristics of these states within the ${}^3{P}_0$ model. The results are compared to values from other phenomenological models, and they may be beneficial in the prospective search for $2^3{P}_1$ meson nonets.

Exclusive π⁰ electroproduction from nucleons can be related to transversity, the tensor charge, and other quantities related to transversity. This process isolates C-parity odd and chiral odd combinations of t-channel exchange quantum numbers. In a hadronic picture the meson production amplitudes for intermediate energy and Q² are determined by C–odd Regge exchanges with final state interactions. The helicity structure for this C-odd process relates to the quark helicity flip, or chiral odd generalized parton distributions (GPDs). Various cross sections and asymmetries will be sensitive to the transversity.

We present measurements of the ep → epπ⁰ cross section extracted at two values of four-momentum transfer Q² = 1.9 GeV² and Q² = 2.3 Gev² at Jefferson Lab Hall A. The kinematic range allows to study the evolution of the extracted hadronic tensor as a function of Q² and W. Results will be confronted with Regge inspired calculations and GPD predictions. An intepretation of our data within the framework of semi-inclusive deep inelastic scattering has also been attempted.