相关论文: On Delta resonance contribution to two-photon exch…
We analyze polarization phenomena for elastic lepton-nucleon scattering, parametrizing the $2\gamma$-exchange contribution, as the product of lepton and nucleon axial vector currents, that correspond to $C=+1$ exchange in the annihilation…
The recoil proton polarization in the $\pi^0$ production off the proton with longitudinally polarized electron beam has been studied as a means to measure quadrupole components in the N to $\Delta$ transition. On top of the $\Delta$…
We reevaluate the Zemach, recoil and polarizability corrections to the hyperfine splitting in muonic hydrogen expressing them through the low-energy proton structure constants and obtain the precise values of the Zemach radius and…
Eta meson production in the proton-proton scattering is dominated by the low-mass meson exchange. We present a brief study on how the type of the exchanged mesons within coupled-channel and multi-resonance model influences the scattering…
We present a detailed study of the effect of the double core polarization (the polarization of the core electrons due to the simultaneous action of the electric dipole and parity-violating weak fields) for amplitudes of the s-s and s-d…
The cross section for polarized and unpolarized electron-proton scattering is calculated taking into account radiative corrections in leading and next-to leading logarithmic approximation. The expression of the cross section is formally…
We consider the radiative corrections to the impact factors of electron and photon. According to a generalized eikonal representation the e\bar e scattering amplitude at high energies and fixed momentum transfers is proportional to the…
We have analyzed the $M_{1+}^{(3/2)}$ and $E_{1+}^{(3/2)}$ multipole amplitudes of pion photoproduction in the framework of fixed-$t$ dispersion relations. Applying the speed plot technique to our results for these multipoles, we have…
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…
We calculate the beam ($B_n$) and target ($A_n$) normal single-spin asymmetries in electron-proton elastic scattering from two-photon exchange amplitudes with resonance intermediate states of spin-parity $1/2^\pm$ and $3/2^\pm$ and mass $W…
We present an improved evaluation of the two-photon exchange correction to the unpolarized lepton-proton elastic scattering process at very low-energies relevant to the MUSE experiment, where only the dominant intermediate elastic proton is…
We present the first measurement of the induced proton polarization P_n in pi^0 electroproduction on the proton around the Delta resonance. The measurement was made at a central invariant mass and a squared four-momentum transfer of W=1231…
Measurements of nuclear $\beta$-decay are commonly used to extract elements of the quark-mixing Cabibbo-Kobayashi-Maskawa (CKM) matrix. The precision of these measurements is currently limited by theoretical uncertainties in electroweak…
The electromagnetic form factors of the nucleon characterize the effect of its internal structure on its response to an electromagnetic probe as studied in elastic electron-nucleon scattering. These form factors are functions of the squared…
Elastic form factors provide information about the low energy structure of composite particles.Recent double polarization coincidence experiments significantly improved our knowledge of proton and neutron form factors. Recoil polarization…
Measurements of the ratio of the proton elastic form factors ($\mu_pG_E/G_M$) using Rosenbluth separation and those using polarization-based techniques show a strong discrepancy, which has persisted both in modern experimental results and…
The deuteron spectrum in n+p -> 2 H(pi pi) at k_n = 1.88 GeV/c and theta_d = 0^o is explained by considering a Delta Delta excitation as the dominant reaction mechanism for the 2 pi production. We present a new theoretical approach based on…
We report the first measurement of the vector analyzing power in inclusive transversely polarized elastic electron-proton scattering at Q^2 = 0.1 (GeV/c)^2 and large scattering angles. This quantity should vanish in the single virtual…
We investigate the effect of high order radiative corrections in unpolarized electron proton elastic scattering and compare with the calculations at lowest order, which are usually applied to experimental data. We show that higher order…
Two-photon exchange contributions have potentially broad ranging impact on several charged lepton scattering measurements. Previously believed to be extremely small, based in part on comparisons of positron scattering and electron…