Related papers: Pion Generalized Dipole Polarizabilities by Virtua…
A measurement is presented of elastic deeply virtual Compton scattering \gamma* p \to \gamma p made using e^+ p collision data corresponding to a luminosity of 46.5 pb^{-1}, taken with the H1 detector at HERA. The cross section is measured…
We analyze virtual Compton scattering off the nucleon at low energies in a covariant, model-independent formalism. We define a set of invariant functions which, once the irregular nucleon pole terms have been subtracted in a gauge-invariant…
We calculate the one-photon loop radiative corrections to charged pion Compton scattering, $\pi^- \gamma \to \pi^- \gamma $. Ultraviolet and infrared divergencies are both treated in dimensional regularization. Analytical expressions for…
Fermilab E781 plans measurements of gamma-Sigma and $\gamma$-pion interactions using a 600 GeV beam of Sigmas and pions, and a virtual photon target. Pion polarizabilities and radiative transitions will be measured in this experiment. The…
Pionic beta decay \pi^+ to \pi^0 e^+ \nu_e is analyzed in chiral perturbation theory with virtual photons and leptons. All electromagnetic corrections up to order e^2 p^2 are taken into account. Theoretical results are confronted with…
Incoherent pion photoproduction on the deuteron in the $\Delta$(1232)-resonance region is investigated with special emphasis on polarization observables. For the elementary pion photoproduction operator an effective Lagrangian model which…
We employ the generalized parton picture to analyze the reaction $\pi^- p \rightarrow D^- \Lambda_c^+$. Thereby it is assumed that the process amplitude factorizes into one for the perturbatively calculable subprocess $\bar{u}\ u\rightarrow…
Cross sections for \nuc{6}{Li}($\gamma$,$\gamma$)\nuc{6}{Li} have been measured at the High Intensity Gamma-Ray Source (\HIGS) and the sensitivity of these cross sections to the nucleon isoscalar polarizabilities was studied. Data were…
The reaction $\gamma d\to \pi^+ nn$ is calculated up to order $\chi^{5/2}$ in chiral perturbation theory, where $\chi$ denotes the ratio of the pion to the nucleon mass. Special emphasis is put on the role of nucleon--recoil corrections…
We discuss the experimental issues confronting measurements of the Virtual Compton Scattering (VCS) reaction ep->ep gamma with electron beam energies 6-30 GeV. We specifically address the kinematics of Deeply Virtual Compton Scattering…
GRAPE-Dilepton is a Monte Carlo event generator for dilepton production in ep collisions. The cross-section calculation is based on the exact matrix elements in the electroweak theory at tree level. The dilepton productions via $\gamma…
We construct the generating functional of two flavor chiral perturbation theory including the effects of virtual photons in the one loop approximation. As an application, we calculate the electromagnetic corrections to the elastic $\pi\pi$…
A rigorous multipole analysis of the recent {\gamma}p -> \pi^{0}p cross section measurement is presented. The data were taken using the photon spectrometer TAPS at the tagged photon beam of the Mainz microtron. The s and p wave multipoles…
We examine manifestations of neutron electromagnetic polarizabilities in coherent Compton scattering from the Helium-3 nucleus. We calculate $\gamma ^3$He elastic scattering observables using chiral perturbation theory to next-to-leading…
The electric (${\alpha}_{\pi}$) and the magnetic (${\beta}_{\pi}$) polarisabilities are fundamental properties of the pion characterising the rigidity of its internal structure. They have been precisely measured at the COMPASS experiment at…
General properties of the differential cross section and of the polarization observables are derived for the $e^++e^-\to N+\bar N$ reaction, in presence of two--photon exchange. Polarization effects are investigated for longitudinally…
This paper reports on the most comprehensive data set obtained on differential and fully integrated cross sections for the process $e p \to e' p \pi^{+} \pi^{-} $. The data were collected with the CLAS detector at Jefferson Laboratory.…
Motivated by the fact that a polarized ${}^3$He nucleus behaves as an `effective' neutron target, we examine manifestations of neutron electromagnetic polarizabilities in elastic Compton scattering from the Helium-3 nucleus. We calculate…
The $\pi^-p \to e^+e^- n$ and $\pi^+n \to e^+e^- p$ reaction cross sections are calculated below and in the vicinity of the vector meson ($\rho^0$, $\omega$) production threshold. These processes are largely responsible for the emission of…
The double pion photoproduction off nucleons near threshold is analyzed in a covariant baryon chiral perturbation theory up to next to leading order, where the $\Delta(1232)$, $N^*(1400)$ and $\rho(770)$ resonances are included as explicit…