Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userAngular distribution of positrons in coherent pair production in deformed crystals
239
0
0.0
(
0
)
Authors
V. V. Parazian
Ask ChatGPT about the research
No Arabic abstract
We investigate the angular distribution of positrons in the coherent process electronpositron pair creation process by high-energy photons in a periodically deformed single crystal with a complex base. The formula for the corresponding differential cross-section is derived for an arbitrary deformation field. The case is considered in detail when the photon enters into the crystal at small angles with respect to a crystallographic axis. The results of the numerical calculations are presented for${mathrm{SiO}}_{2}$ and diamond single crystals and Moliere parameterization of the screened atomic potentials in the case of the deformation field generated by the acoustic wave of S-type.
rate research
Read More
We investigate the angular distribution of photons in the coherent bremsstrahlung process by high-energy electrons in a periodically deformed single crystal with a complex base. The formula for the corresponding differential cross-section is derived for an arbitrary deformation field. The case is considered in detail when the electron enters into the crystal at small angles with respect to a crystallographic axis. The results of the numerical calculations are presented for SiO2 single crystal and Moliere parameterization of the screened atomic potentials in the case of the deformation field generated by the acoustic wave of S -type.
In the present paper we investigate coherent bremsstrahlung of high energy electrons moving in a periodically deformed single crystal with a complex base. The formula for corresponding differential cross-section is derived for an arbitrary deformation field. The conditions are discussed under which the influence of the deformation is important. The case is considered in detail when the electron enters into the crystal at small angles with respect to a crystallographic axis. It is shown that in dependence of the parameters, the presence of the deformation can either enhance or reduce the bremsstrahlung cross-section.
We investigate the coherent electron-positron pair creation by high-energy photons in a periodically deformed single crystal with a complex base. The formula for the corresponding differential cross-section is derived for an arbitrary deformation field. The conditions are specified under which the influence of the deformation is considerable. The case is considered in detail when the photon enters into the crystal at small angles with respect to a crystallographic axis. The results of the numerical calculations are presented for $mathrm{SiO}_{2}$ single crystal and Moliere parametrization of the screened atomic potentials in the case of the deformation field generated by the acoustic wave of $S$ type. In dependence of the parameters, the presence of deformation can either enhance or reduce the pair creation cross-section. This can be used to control the parameters of the positron sources for storage rings and colliders.
We assume that a massive Dirac neutrino is characteized by two phenomenological parameters, a magnetic moment, and a charge radius, and we calculate the cross-section of the scattering $e^+e^-to u bar u$ in a left-right symmetric model. We also analyze the angular distribution of the neutrino (antineutrino) with respect to the original direction of the electron (positron) to different state of helicity of the neutrino. We find that the favored directions for the neutrino (antineutrino) with respect to the electron (positron) is forward $(theta =0)$ and backward $(theta= pi)$, and is not very probable in the perpendicular direction $(theta = frac{pi}{2})$. The calculation is for $phi = -0.005$ and $M_{Z_2}=500$ $GeV$, parameters of the Left-Right symmetric model.
We study the time-dependent solitonic gauge fields in scalar QED, in which a charged particle has the energy of reflectionless P{o}sch-Teller potential with natural quantum numbers. Solving the quantum master equation for quadratic correlation functions, we find the exact pair-production rates as polynomials of inverse square of hyperbolic cosine, which exhibit solitonic characteristics of a finite total pair production per unit volume and a non-oscillatory behavior for the entire period, and an exponentially decaying factor in asymptotic regions. It is shown that the solitonic gauge fields are the simplest solutions of the quantum master equation and that the back-reaction of the produced pairs does not destabilize the solitonic gauge fields.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
