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Corrections of two-photon exchange to proton and neutron electromagnetic form factors are employed to study the effect of two-photon exchange on the deuteron electromagnetic form factors. Numerical results of the effect are given. It is…

Nuclear Theory · Physics 2009-07-30 Yu Bing Dong , D. Y. Chen

In this talk I address two high impact physics programs that require the use of polarized and unpolarized positron beams in addition to using electron beams of the same energy. First, I address what will be gained from using positron beams…

Nuclear Experiment · Physics 2018-06-13 Volker D. Burkert

This paper serves as a report on the large amount of analysis done in conjunction with the polarized proton program at RHIC. This comprises elastic scattering data of protons on protons in colliding beam or fixed target mode and proton…

High Energy Physics - Phenomenology · Physics 2008-11-26 T. L. Trueman

An analysis of all experimental data of 50's - 90's on elastic gamma-p scattering at photon energies below 150 MeV (10 experimental works) is performed in order to determine the electric (alpha_p) and magnetic (beta_p) polarizabilities of…

Nuclear Experiment · Physics 2007-05-23 P. S. Baranov , A. I. L'vov , V. A. Petrun'kin , L. N. Shtarkov

The proton elastic form factor ratio can be measured either via Rosenbluth separation in an experiment with unpolarized beam and target, or via the use of polarization degrees of freedom. However, data produced by these two approaches show…

Nuclear Experiment · Physics 2021-11-03 Ethan Cline , Jan C. Bernauer , Axel Schmidt

We perform a model-independent phenomenological analysis of experimental data on proton form factors ratio. We find that only one of the two photon exchange amplitudes, which we call $\delta G_M$, is responsible for the discrepancy between…

High Energy Physics - Phenomenology · Physics 2008-11-26 Dmitry Borisyuk , Alexander Kobushkin

We study elastic N$\alpha $ scattering and produce a quantitative correlation between the range of the effective potential and the energy of the system. This allows the identification of the waves and energies for which the scattering may…

Nuclear Theory · Physics 2016-08-15 L. A. Barreiro , R. Higa , C. L. Lima , M. R. Robilotta

Two-photon exchange (TPE) contributions to elastic electron-proton scattering in the forward regime and in leading log $\sim t\ln|t|$ approximation in the momentum transfer $|t|$ are considered. The imaginary part of TPE amplitude in these…

Nuclear Theory · Physics 2014-12-03 Mikhail Gorchtein

One of the most surprising discoveries made at Jefferson Lab has been the discrepancy in the determinations of the proton's form factor ratio $\mu_p G_E^p/G_M^p$ between unpolarized cross section measurements and the polarization transfer…

We present an exact evaluation of the two-photon exchange contribution to the elastic lepton-proton scattering process at low-energies using heavy baryon chiral perturbation theory. The evaluation is performed including next-to-leading…

High Energy Physics - Phenomenology · Physics 2023-11-30 Poonam Choudhary , Udit Raha , Fred Myhrer , Dipankar Chakrabarti

The ratio of the proton elastic electromagnetic form factors, $G_{Ep}/G_{Mp}$, was obtained by measuring $P_{t}$ and $P_{\ell}$, the transverse and longitudinal recoil proton polarization components, respectively, for the elastic $\vec e p…

Nuclear Experiment · Physics 2014-11-18 V. Punjabi , C. F. Perdrisat

The general expressions for parity violation observables in elastic scattering of polarized and/or unpolarized electrons from unpolarized deuterons are given and are numerically evaluated for the kinematics of SAMPLE, PVA4 and G0…

Nuclear Theory · Physics 2015-05-13 S. Ahmad , S. K. Singh , H. Arenhoevel

We calculated two--photon exchange effects for elastic electron--proton scattering at high momentum transfers. The corresponding nucleon Compton amplitude is defined by two space--like virtual photons that appear to have significant…

High Energy Physics - Phenomenology · Physics 2017-08-23 Andrei Afanasev , Igor Akushevich , N. P. Merenkov

The complex Kohn variational principle and the (correlated) hyperspherical harmonics method are applied to study the proton-deuteron elastic scattering at energies above the deuteron breakup threshold. Results for the elastic cross section…

Nuclear Theory · Physics 2009-10-31 A. Kievsky , S. Rosati , M. Viviani

We consider the analyzing power on a spin-0 nuclear target. This observable is related to the imaginary part of the two-photon-exchange (box) diagram. We consider the contributions of elastic and inelastic intermediate states. The former…

Nuclear Theory · Physics 2008-11-26 Mikhail Gorchtein , Charles J. Horowitz

Leading electroweak corrections play an important role in precision measurements of the strange form factors. We calculate the two-photon-exchange (TPE) and $\gamma Z$-exchange corrections to the parity-violating asymmetry of the elastic…

High Energy Physics - Phenomenology · Physics 2008-11-26 Hai Qing Zhou , Chung Wen Kao , Shin Nan Yang

We present a simple parameterization of the two-photon exchange amplitude in elastic electron-proton scattering, suitable for fast numerical evaluation.

High Energy Physics - Phenomenology · Physics 2018-11-05 Dmitry Borisyuk , Alexander Kobushkin

We investigate the polarization parameters in low-energy antiproton-proton elastic ($\bar{p}p\rightarrow\bar{p}p$) and charge-exchange ($\bar{p}p\rightarrow\bar{n}n$) scattering. The predictions for unmeasured observables are based on our…

High Energy Physics - Phenomenology · Physics 2013-05-27 Daren Zhou , Rob G. E. Timmermans

We present a novel method for the global analysis of elastic electron-proton scattering when combining data sets from experiments with different overall normalization uncertainties. The method is a modification of one employed by the NNPDF…

High Energy Physics - Phenomenology · Physics 2024-08-07 Craig McRae , P. G. Blunden

The details of the calculation of the two-boson exchange effects in the parity-violating elastic $ep$ scattering within a simple hadronic model, including both the nucleon and $\Delta(1232)$-resonance intermediate states, are presented. We…

Nuclear Theory · Physics 2010-04-14 Hai Qing Zhou , Chung Wen Kao , Shin Nan Yang , Keitaro Nagata