Conveners
Proton Radius and Two Photon exchange
- Abhay Deshpande (Stonybrook)
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Dr Michael Kohl (Hampton University)2/2/17, 11:00 AMHard two-photon exchange has been favored theoretically to explain the previously observed discrepancy in measurements of the elastic proton electric-to-magnetic form factor ratio with polarized and unpolarized methods. Several experiments have been carried out to investigate the effects of two-photon exchange. The OLYMPUS experiment at DESY has been one of three dedicated experiments to use...Go to contribution page
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Prof. John Ralston (University of Kansas)2/2/17, 11:20 AMThe "proton size puzzle'' and the "muon anomalous moment problem'' are incomplete descriptions of significant discrepancies between experiments and standard model calculations. Actually the field has confronted a new regime of ultra-precise physics where traditional piece-meal analysis methods are no longer self-consistent. Determining the proton size $r_{p}$, the Rydberg constant...Go to contribution page
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Alexander Gramolin (Budker Institute of Nuclear Physics)2/2/17, 11:40 AMThe ratio of the elastic $e^+ p$ to $e^- p$ scattering cross sections has been measured precisely at the VEPP-3 storage ring (Novosibirsk, Russia). This allows us to determine the hard two-photon exchange contribution to elastic electron-proton scattering, which is believed to be the cause of the apparent discrepancy between the Rosenbluth and polarization transfer methods of measuring the...Go to contribution page
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Prof. Gary Goldstein (Tufts University)2/2/17, 12:00 PMChiral Even and Odd Generalized Parton Distributions (GPDs) for Valence Quarks are obtained in a "flexible" spectator model. The parametrization is constrained by nucleon form factors, PDFs and some earlier Deeply Virtual Compton Scattering data. The model has been extended to cover the full range of experimentally attainable kinematics. A broad range of measured and measurable deeply virtual...Go to contribution page
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Abha Rajan (University of Virginia)2/2/17, 12:20 PMIt is well known that the valence quark spins do not add up to the proton spin. We probe the partonic orbital angular momentum (OAM) contribution to the spin sum rules using the Generalized Parton Distributions(GPDs) and Generalized Transverse Momentum Distributions (GTMDs). These functions are obtained by parameterizing the QCD quark quark correlator function in different scenarios. By...Go to contribution page