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Related papers: Exact Relations for Two-Photon-Exchange Effect in …

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In this work, the two-photon-exchange (TPE) effects in $e^+e^- \rightarrow \pi^+ \pi^-$ at small $\sqrt{s}$ are discussed within a hadronic model. In the limit $m_e\rightarrow 0$, the TPE contribution to the amplitude can be described by…

High Energy Physics - Phenomenology · Physics 2020-09-30 Zhong-Hua Zhao , Hui-Yun Cao , Hai-Qing Zhou

We compute the corrections from two-photon and photon-Z exchange in parity-violating elastic electron-proton scattering, used to extract the strange form factors of the proton. We use a hadronic formalism that successfully reconciled the…

Nuclear Theory · Physics 2014-11-18 J. A. Tjon , W. Melnitchouk

In this work, the two-photon-exchange (TPE) effects in the unpolarized $\mu p$ scattering are discussed within the hadronic model where the intermediate states $N,\Delta$ and $\sigma$ are considered. The contribution from the $N$…

Nuclear Theory · Physics 2017-02-22 Hai-Qing Zhou

Current status of the two-boson exchange contributions to elastic electron-proton scattering, both for parity conserving and parity-violating, is briefly reviewed. How the discrepancy in the extraction of elastic nucleon form factors…

Nuclear Theory · Physics 2015-05-30 Shin Nan Yang

We evaluate the two-photon exchange (TPE) correction to the muon-proton elastic scattering at small momentum transfer. Besides the elastic (nucleon) intermediate state contribution, which is calculated exactly, we account for the inelastic…

High Energy Physics - Phenomenology · Physics 2016-03-23 O. Tomalak , M. Vanderhaeghen

We present the dispersion relation approach based on unitarity and analyticity to evaluate the two-photon exchange contribution to elastic electron-proton scattering. The leading elastic and first inelastic $\pi N$ intermediate state…

High Energy Physics - Phenomenology · Physics 2018-07-04 Oleksandr Tomalak

It is shown that the amplitude of elastic ed scattering beyond Born approximation contains six generalized form factors, but only three linearly independent combinations of them (generalized charge, quadrupole and magnetic form factors)…

Nuclear Theory · Physics 2015-03-17 A. P. Kobushkin , Ya. D. Krivenko-Emetov

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 apply a subtracted dispersion relation formalism with the aim to improve predictions for the two-photon exchange corrections to elastic electron-proton scattering observables at finite momentum transfers. We study the formalism on the…

High Energy Physics - Phenomenology · Physics 2016-01-29 O. Tomalak , M. Vanderhaeghen

We calculate two-photon exchange amplitude for the elastic electron-proton scattering in the framework of dispersion relations. The imaginary part of the amplitude is determined by unitarity. Since in the unitarity relation intermediate…

Nuclear Theory · Physics 2008-11-26 Dmitry Borisyuk , Alexander Kobushkin

We evaluate the two-photon exchange (TPE) correction to the unpolarized elastic electron-proton scattering at small momentum transfer $ Q^2 $. We account for the inelastic intermediate states approximating the double virtual Compton…

High Energy Physics - Phenomenology · Physics 2016-02-03 O. Tomalak , M. Vanderhaeghen

In this work, the two-photon-exchange (TPE) effects in $ep\rightarrow en\pi^+$ at small $-t$ are discussed within a hadronic model. Under the pion dominance approximation the TPE contribution to the amplitude can be described by a scalar…

High Energy Physics - Phenomenology · Physics 2022-03-29 Hui-Yun Cao , Hai-Qing Zhou

We evaluate the pion-nucleon intermediate-state contribution to the two-photon exchange (TPE) correction in the elastic electron-nucleon scattering within a dispersive framework. We calculate the contribution from all $\pi N$ partial waves…

High Energy Physics - Phenomenology · Physics 2017-05-10 O. Tomalak , B. Pasquini , M. Vanderhaeghen

We evaluate the corrections of the two-photon exchange (TPE) process on the $\gamma^* N\Delta$ transition form factors. The contributions of the TPE process to the $eN\rightarrow e\Delta(1232)\rightarrow eN\pi$ are calculated in a hadronic…

Nuclear Theory · Physics 2017-12-06 Hai-Qing Zhou , Shin Nan Yang

The general spin structure of the matrix element, taking into account the two--photon exchange contribution, for the elastic electron (positron) --deuteron scattering has been derived using general symmetry properties of the hadron…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. I. Gakh , E. Tomasi-Gustafsson

We calculate two-photon exchange (TPE) amplitudes for the elastic electron-proton scattering, and take into account intermediate hadronic states containing \pi N system with total angular momentum 1/2 or 3/2, which includes 8 different…

High Energy Physics - Phenomenology · Physics 2015-09-16 Dmitry Borisyuk , Alexander Kobushkin

We calculate two-photon exchange amplitude for the elastic electron-pion scattering in the dispersion-relation inspired approach, including both elastic and inelastic contributions. The latter was modelled as a sum of \rho and b_1(1235)…

High Energy Physics - Phenomenology · Physics 2015-03-17 Dmitry Borisyuk , Alexander Kobushkin

We study the leading electroweak corrections in the precision measurement of the strange form factors. Specifically, we calculate the two-boson-exchange (TBE), two-photon-exchange (TPE) plus $\gamma Z$-exchange ($\gamma Z$E), corrections…

Nuclear Theory · Physics 2010-11-22 Keitaro Nagata , Hai Qing Zhou , Chung Wen Kao , Shin Nan Yang

We evaluate the two-photon exchange correction to the elastic electron-proton scattering cross section within a dispersive framework. Besides the elastic contribution, we account for all $\pi N$ intermediate state contributions using the…

High Energy Physics - Phenomenology · Physics 2017-11-15 O. Tomalak , B. Pasquini , M. Vanderhaeghen

We evaluate the two-photon exchange correction to the unpolarized cross section in the elastic muon-proton scattering within dispersion relations. One of the six independent invariant amplitudes requires a subtraction. We fix the…

High Energy Physics - Phenomenology · Physics 2024-10-28 Oleksandr Tomalak , Marc Vanderhaeghen