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Related papers: Delta--Excitation and Exchange Corrections for NN-…

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The most recent data on beam asymmetries, $\Sigma$, and beam-target asymmetries, $E$, from the CLAS Collaboration, together with the previous data on differential cross sections and beam asymmetries from the CLAS and LEPS Collaborations,…

High Energy Physics - Phenomenology · Physics 2022-06-01 Neng-Chang Wei , Ai-Chao Wang , Fei Huang , Kanzo Nakayama

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

In this work, an off-shell extrapolation is proposed for the Regge-model $NN$ amplitudes of \cite{FVO_Reggemodel}. A prescription for extrapolating these amplitudes for one nucleon off-shell in the initial state are given. Application of…

Nuclear Theory · Physics 2013-12-04 William P. Ford , J. W. Van Orden

Within an effective Lagrangian model, we present calculations for cross sections of the dilepton production in proton-proton and proton-neutron collisions at laboratory kinetic energies in 1-5 GeV range. Production amplitudes include…

High Energy Physics - Phenomenology · Physics 2009-11-10 R. Shyam , U. Mosel

We examine the role of the elementary isoscalar pion--nucleon scattering amplitude in the description of the processes $pp \to pp\pi^0$ and $pp\to d\pi^+$ at threshold. We argue that the presently used tree level dimension two approximation…

Nuclear Theory · Physics 2009-10-30 C. Hanhart , J. Haidenbauer , M. Hoffmann , Ulf-G. Meißner , J. Speth

We derive the long-range components of the nucleon-nucleon (NN) two-pion-exchange potential with an intermediate Roper resonance. Leading-order interactions in heavy-baryon chiral perturbation theory are considered. NN phase shifts with…

Nuclear Theory · Physics 2026-03-02 Yang Xiao , Li-Sheng Geng , U. van Kolck

In this work we investigate the reaction $\gamma p\to\pi^-\Delta^{++}$ in the Reggeized model for $\pi(138)+\rho(775)+a_2(1320)$ exchanges in the $t$-channel. For a convergence of the reaction cross section at high energies the minimal…

High Energy Physics - Phenomenology · Physics 2018-08-01 Byung-Geel Yu , Kook-Jin Kong

We revisit the emissivity from neutrino pair bremsstrahlung in neutron-neutron scattering, nn -> nn nu nubar, which was calculated from the one-pion exchange potential including correlation effects by Friman and Maxwell. Starting from the…

Nuclear Theory · Physics 2009-11-10 A. Schwenk , P. Jaikumar , C. Gale

Model-independent effects of $\Delta$(1232) excitation on nucleon polarizabilities are computed in a Lorentz-invariant fashion. We find a large effect of relative order $(M_\Delta - M)/M$ in some of the spin polarizabilities, with the…

Nuclear Theory · Physics 2009-11-10 Vladimir Pascalutsa , Daniel R. Phillips

The scaling of photoproduction $\gamma p\to\pi^0 p$ is investigated in the Reggeized model with $N^*$ and $\Delta$ resonances included to describe resonance peaks up to photon energy $E_\gamma$= 3 GeV. Given the $t$-channel exchanges…

Nuclear Theory · Physics 2016-08-09 Kook-Jin Kong , Tae Keun Choi , Byung-Geel Yu

Roles of the $\Delta (1232)$, ${N}^{*}(1520)$, and ${N}^{*}(1650)$ resonances in the $\gamma p\to{\pi }^{0}{\pi }^{0}p $ reaction near threshold is investigated within an effective Lagrangian approach. We have calculated the differential…

High Energy Physics - Phenomenology · Physics 2025-01-28 Meng-Yuan Dai , Si-Wei Liu , Cheng Chen , De-Min Li , En Wang , Ju-Jun Xie

We calculate in baryon chiral perturbation theory the relativistic $1/M^2$-corrections to the leading order two-pion exchange diagrams. We give explicit expressions for the corresponding one-loop NN-amplitudes in momentum space. The…

Nuclear Theory · Physics 2009-11-07 N. Kaiser

The nuclear response functions for high energy electron scattering were calculated in the wide region of excitation energy. The three typical regions were studied: the quasi-elastic region, the $\Delta$-excitation region and the…

Nuclear Theory · Physics 2009-10-30 Valeriya Gadiyak , Vladimir Dmitriev

The role of the nucleon resonances ($N^*$) in $\omega$ photoproduction is investigated by using the resonance parameters predicted by Capstick and Roberts [Phys. Rev. D {\bf 46}, 2864 (1992); {\bf 49}, 4570 (1994)]. In contrast with the…

Nuclear Theory · Physics 2009-11-06 Yongseok Oh , Alexander I. Titov , T. -S. H. Lee

The charge changing weak production of Delta in nucleons and nuclei is studied. The reactions e^{-} p -> Delta^{0} \nu_{e} and e^{+} p -> Delta^{++} \bar{\nu}_{e} are considered as a possible source of information about the weak N-Delta…

Nuclear Theory · Physics 2011-02-09 L. Alvarez-Ruso , E. Oset , S. K. Singh , M. J. Vicente Vacas

A novel soft-photon amplitude is proposed to replace the conventional Low soft-photon amplitude for nucleon-nucleon bremsstrahlung. Its derivation is guided by the standard meson-exchange model of the nucleon-nucleon interaction. This new…

Nuclear Theory · Physics 2009-10-28 M. K. Liou , R. Timmermans , B. F. Gibson

The uncertainty in the contribution to the Lamb shift in muonic hydrogen, $\Delta E^{subt}$ arising from proton polarizability effects in the two-photon exchange diagram at large virtual photon momenta is shown large enough to account for…

Nuclear Theory · Physics 2015-06-11 Gerald A. Miller

Within fixed-t dispersion relations the results of new VPI partial-wave analysis for the multipole amplitudes $M_{1+}^{3/2},E_{1+}^{3/2}$ are successfuly described, and the resonance and nonresonance contributions into these amplitudes are…

High Energy Physics - Phenomenology · Physics 2007-05-23 I. G. Aznauryan

Phenomenological expressions are derived for rates of the $\Delta (1232)$ radiative and Dalitz decays, $\Delta (1232)$ $\to N\gamma$ and $\Delta (1232)$ $\to Ne^{+}e^{-}$. Earlier calculations of these decays are commented.

Nuclear Theory · Physics 2009-11-07 M. I. Krivoruchenko , Amand Faessler

The exchange-driven contribution to the magnetoelectric susceptibility $\hat\alpha$ is formulated using a microscopic model Hamiltonian coupling the spin degrees of freedom to lattice displacements and electric field, which may be…

Materials Science · Physics 2014-05-13 Sai Mu , A. L. Wysocki , K. D. Belashchenko