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Related papers: Polarization transfer in $\vec{e}^+p \rightarrow e…

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We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The result is A = -15.05 +- 0.98(stat) +- 0.56(syst) ppm at the kinematic point theta_lab = 12.3 degrees and Q^2 =…

Nuclear Experiment · Physics 2010-05-27 HAPPEX collaboration , K. A. Aniol

The ratio of the proton's elastic electromagnetic form factors $G_{Ep}/G_{Mp}$ was obtained by measuring $P_{t}$ and $P_{\ell}$, the transverse and longitudinal recoil proton polarization, respectively. For the elastic reaction $\vec e p…

We calculate the two-boson-exchange (TBE) corrections to the parity-violating asymmetry of the elastic electron-proton scattering in a simple hadronic model including the nucleon and the $\Delta(1232)$ intermediate states. We find that…

Nuclear Theory · Physics 2009-01-16 Shin Nan Yang , Keitaro Nagata , Hai Qing Zhou , Chung Wen Kao

We report a high precision measurement of electron beam polarization using Compton polarimetry. The measurement was made in experimental Hall A at Jefferson Lab during the CREX experiment in 2020. A total uncertainty of dP/P=0.36% was…

Modern experiments with heavy ion-leptons collisions open the possibility to measure the deviation of cross section of small angles electron(positron)-ion elastic scattering from the Rutherford formula due to multiple virtual photons…

High Energy Physics - Phenomenology · Physics 2009-08-18 E. A. Kuraev , M. Shatnev , E. Tomasi-Gustafsson

The recoil proton polarization was measured in the d(epol,e' ppol)n reaction in Hall A of the Thomas Jefferson National Accelerator Facility (JLab). The electron kinematics were centered on the quasielastic peak (x_{Bj}~1) and included…

Nuclear Experiment · Physics 2009-09-09 B. Hu , M. K. Jones , P. E. Ulmer

The parity-conserving single-spin beam asymmetry of elastic electron-proton scattering is induced by an absorptive part of the two-photon exchange amplitude. We demonstrate that this asymmetry has logarithmic and double-logarithmic…

High Energy Physics - Phenomenology · Physics 2014-11-17 Andrei Afanasev , N. P. Merenkov

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 extend the general formalism of two-photon exchange to elastic lepton-nucleon scattering by accounting for all lepton mass terms. We then perform a numerical estimate of the muon-proton scattering at low momentum transfer in view of the…

High Energy Physics - Phenomenology · Physics 2014-07-16 O. Tomalak , M. Vanderhaeghen

A comparison between polarization-transfer to a bound proton in quasi-free kinematics by the A$(\vec{e},e'\vec p)$ knockout reaction and that in elastic scattering off a free proton can provide information on the characteristics of the…

Due to the inconsistency in the results of the GEp/Gmp ratio of the proton, as extracted from the Rosenbluth and recoil polarization techniques, high precision measurements of the e-p elastic scattering cross sections were made at Q^2 =…

Nuclear Experiment · Physics 2009-09-29 Issam A. Qattan

Structure functions and polarization observables in elastic scattering of longitudinally polarized electron on polarized deuteron are considered within approximation of one-photon + two-photon exchange. It is shown that contribution of…

The ratio of the squares of the electric and magnetic proton form factors is shown to be proportional to the ratio of the cross sections for the elastic scattering of an unpolarized electron on a partially polarized proton with and without…

High Energy Physics - Phenomenology · Physics 2009-03-12 M. V. Galynskii , E. A. Kuraev , Yu. M. Bystritskiy

The two-photon-exchange (TPE) contribution in $ep\rightarrow ep\pi ^0$ with $W=M_{\Delta}$ and small $Q^2$ is calculated and its corrections to the ratios of electromagnetic transition form factors $R_{EM} = E_{1+}^{(3/2)}/M_{1+}^{(3/2)} $…

Nuclear Theory · Physics 2017-03-08 Hai-Qing Zhou , Shin Nan Yang

It is demonstrated that an emission of collinear photons by the polarized initial electron in elastic electron-proton polarization transfer scattering leads to an apparent shifting of real events with small momentum transfer into the data…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Dubnička , E. Kuraev , M. Sečanský , A. Vinnikov

In these notes we present a detailed and complete scheme for the calculation of polarization phenomena in elastic electron-nucleon scattering. The longitudinal and transversal components of the polarization for the scattered nucleon,…

Nuclear Theory · Physics 2007-05-23 Michail P. Rekalo , Egle Tomasi-Gustafsson

Polarization transfer in quasi-elastic nucleon knockout is sensitive to the properties of the nucleon in the nuclear medium, including possible modification of the nucleon form factor and/or spinor. In our recently completed experiment…

Nuclear Experiment · Physics 2019-08-13 S. Strauch

We report the first measurements of the transverse ($P_{x}$ and $P_{y}$) and longitudinal ($P_{z}$) components of the polarization transfer to a bound proton in the deuteron via the $^{2}\mathrm{H}(\vec{e},e'\vec{p})$ reaction, over a wide…

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

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