scholarly journals Coherent pair creation in linear colliders

1989 ◽  
Vol 63 (17) ◽  
pp. 1796-1799 ◽  
Author(s):  
Pisin Chen ◽  
Valery I. Telnov
2006 ◽  
Vol 20 (25) ◽  
pp. 1617-1627 ◽  
Author(s):  
A. R. MKRTCHYAN ◽  
A. A. SAHARIAN ◽  
V. V. PARAZIAN

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 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.


2002 ◽  
Vol 17 (39) ◽  
pp. 2571-2580 ◽  
Author(s):  
A. R. MKRTCHYAN ◽  
A. A. SAHARIAN ◽  
L. SH. GRIGORYAN ◽  
B. V. KHACHATRYAN

The influence of hypersonic waves excited in a single crystal is investigated on the process of electron–positron pair creation by high-energy photons. The coherent part of the corresponding differential cross-section is derived as a function of the amplitude and wave number of the hypersound. The values of the parameters are specified for which the latter affects remarkably on the pair creation cross-section. It is shown that under certain conditions the presence of hypersonic waves can result in enhancement of the process cross-section.


1989 ◽  
Vol 327 (2) ◽  
pp. 285-306 ◽  
Author(s):  
M. Jacob ◽  
Tai Tsun Wu

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
David Vegh

Abstract The classical motion of a Nambu-Goto string in AdS3 spacetime is governed by the generalized sinh-Gordon equation. It can locally be reduced to the sinh-Gordon (shG), cosh-Gordon (chG), or Liouville equation, depending on the value of the scalar curvature of the induced metric. In this paper, I examine solutions that contain both shG-type and chG-type regions. The boundary between these regions moves with the speed of light. I show that near such boundaries (generalized) solitons can be classically pair-produced. The solitons move subluminally (superluminally) in the shG (chG) region on the worldsheet, and they correspond to cusps on the string. A direct energy cascade is observed at the moment of pair-creation.For the calculations, I use an exact discretization of the equation of motion. The solutions are segmented strings. In this discrete system, pair-production leads to a complete evaporation of the shG region. The final state is a gas of cusps in a chG environment.


2016 ◽  
Vol 31 (02n03) ◽  
pp. 1641031 ◽  
Author(s):  
S. P. Gavrilov ◽  
D. M. Gitman

We consider QED with strong external backgrounds that are concentrated in restricted space areas. The latter backgrounds represent a kind of spatial x-electric potential steps for charged particles. They can create particles from the vacuum, the Klein paradox being closely related to this process. We describe a canonical quantization of the Dirac field with x-electric potential step in terms of adequate in- and out-creation and annihilation operators that allow one to have consistent particle interpretation of the physical system under consideration and develop a nonperturbative (in the external field) technics to calculate scattering, reflection, and electron-positron pair creation. We resume the physical impact of this development.


Sign in / Sign up

Export Citation Format

Share Document