Related papers: Pion polarisabilities and bremsstrahlung
We calculate the first Coulomb correction to the spectra of two processes: the electron bremsstrahlung and electron-positron photoproduction in the Coulomb field. We show that, in contrast to the results obtained in the Born approximation…
The differential cross section of double bremsstrahlung from high-energy electron in the electric field of heavy atoms is derived. The results are obtained with the exact account of the atomic field by means of the quasiclassical…
An intense, short laser pulse incident on a transparent dielectric can excite electrons from valence to the conduction band. As these electrons undergo scattering, both from phonons and ions, they emit bremsstrahlung radiation. Here we…
We study the non-linear Breit-Wheeler process $\vec \gamma' + \vec L \to e^+ + e^-$ in the interaction of linearly polarized probe photons ($\vec \gamma'$) with a linearly polarized laser beam ($\vec L$). In particular, we consider the…
This paper presents an analysis of pi- Pb -> X- Pb -> pi-pi-pi+ Pb events at 190 GeV/c beam momentum and very low four-momentum transfer t'<0.001 GeV^2/c^2. Coherent scattering off the nucleus as a whole dominates with contributions from…
We evaluate the amplitude for gamma gamma --> pi^+ pi^- to two loops in the framework of chiral perturbation theory.The three new coupling constants that enter the result at this order in the low-energy expansion are estimated via resonance…
Intense light with frequencies above typical atomic or molecular ionization potentials as provided by free-electron lasers couples many photons into extended targets such as clusters and biomolecules. This implies, in contrast to…
At low photon energies, the potential models of nucleus-nucleus bremsstrahlung are based on electric transition multipole operators, which are derived either only from the nuclear current or only from the charge density by making the…
The radiation at collision of high-energy particles is formed over a rather long distances and therefore is sensitive to an environment. In particular the smallness of the transverse dimensions of the colliding beams leads to suppression of…
Within the framework of a thermal model with its parameters fitted to the results from an isospin-dependent Boltzmann-Uehling-Uhlenbeck (IBUU) transport model, we study the pion in-medium effect on the charged-pion ratio in heavy-ion…
A research program has been started to study experimentally the near-threshold photodissociation of nuclides in the chain of cosmic heavy element production with bremsstrahlung from the ELBE accelerator. An important prerequisite for such…
A possible setup for the experimental verification of linear Breit-Wheeler pair creation of electrons and positrons in photon-photon collisions is studied theoretically. It combines highly energetic bremsstrahlung photons, which are assumed…
In this paper the improved multipolar model of bremsstrahlung accompanied the $\alpha$-decay is presented. The angular formalism of calculations of the matrix elements, being enough complicated component of the model, is stated in details.…
We calculate the decay of pionium atoms into two photons. The pion polarizability gives rise to a 10% correction to the corresponding decay width for pointlike pions. This opens the possibility to obtain the difference between the electric…
The theory of bremsstrahlung $e \to e\gamma$ by extremely high energy electrons passing through ordinary matter has been qualitatively incomplete. We revisit the suppression of bremsstrahlung by the Landau-Pomeranchuk-Migdal (LPM) effect,…
We use the semi-analytical program RCFORGV to evaluate radiative corrections to one-photon radiative emission in the high-energy scattering of pions in the Coulomb field of a nucleus with atomic number Z. It is shown that radiative…
The reactions $\gamma p\to\pi^0 p$ and $\gamma p\to\pi^+ n$ are analyzed in a semi-phenomenological approach up to $E\sim2.3$ GeV. Fits to differential cross section and single and double polarization observables are performed. A good…
The problem of a spin 1 charged particle with electromagnetic polarizability, obeying a generalized 15-component quantum mechanical equation, is investigated in presence of the external Coulomb potential. With the use of the Wigner's…
Two charged pion final states are studied for GeV photons incident on protons. The data come from Thomas Jefferson National Accelerator Facility using the CLAS detector. A tagged photon beam of 0.5-2.4 GeV/c was produced through…
High energy neutrino bremsstrahlung $\nu \to \nu + \gamma$ in a strong magnetic field ($B \gg B_s$) is studied in the framework of the Standard Model (SM). A resonance probability and a four-vector of the neutrino energy and momentum loss…