Relativistic electron scattering from a freely movable proton in a strong laser field

Abstract

We study the electron scattering from the freely movable spin-5 proton in the presence of a linearly polarized laser field in the first Born approximation. The dressed state of the electron is described by a time-dependent wave function derived from a perturbation treatment (in a laser field). With the aid of numerical results we explore the dependencies of the differential cross section (DCS) on the electron-impact energy. Due to the mobility of the target, the DCS of this process is modified compared to the Mott scattering, especially in large scattering angles. PACS number(s): 34.80.Qb, 34.80.Dp Physics related to the radiative processes experienced by free electrons inside a strong electrom agnetic field w ere studied since the advent o f laser sources in the early 1960s [1,2]. An overview on this field can be found in the textbooks by Faisal [3], M ittlem an [4], Fedorov [5], and som e other recent papers [6-8]. M ost o f these studies are carried out in the regim e o f nonrelativistic collisions and for low-or m oderate-field intensities. There are also som e studies that have been carried out to investigate theoretically the relativistic potential. In the presence o f ultrastrong lasers, a relativistic treatm ent becom es im perative (even for slow electrons). In the treatm ents o f Refs. [9-11], effects related to the electron spin have been neglected, and the electron has been considered as a K lein-G ordon particle. Based on the theory of Refs. [12,13], Szym anow ski e ta l. [14] and Szym anow ski and M aquet [15] investigated the spin effect in the relativistic potential scattering in the presence o f a circularly polarized field. However, as they stated, the resulting expression for the circularly polarized field turned out to be m ore tractable than for the general case o f elliptical or linear polarizations, and then Li et al. studied the case o f a linearly polarized field [16], A ttaourti et al. studied the cases o f circularly and elliptically polarized fields [17], and M anaut et al. investigated the case o f polarized electrons [18]. The present B rief Report addresses the problem o f an electron scattering off the freely m ovable target in the presence o f a m onochrom atic linearly polarized hom ogeneous laser field. The aim o f this B rief R eport is to add som e physical insight and to show the m odification o f a differential cross section (DCS) due to the m ovable target and com pare it to the case o f M ott scattering. We investigate, to be specific, the recoil effect in relativistic scattering o f an electron from a freely m ovable proton. A DCS is derived by the trace procedure with the aid o f FEYNCALC [19] and M athem atica, and a sim plified form is given for specific cases. U nless specifically stated, atom ic units h = m = e = 1 are used throughout, and the m etric tensor is g^ = diag(l,-1,-1,-1).In the regim e o f laser field intensity as considered in this B rief Report, the field can be treated as classically, w hich does not allow pair creation [20], its four-potential that sa...

Elastic electron-proton scattering in the presence of a circularly polarized laser field

“…The first simple physical explanation to which we can attribute this behavior is as follows: the electron, when embedded in a circularly polarized laser field, of course moves in perpendicular electric and magnetic fields, but at the same time rotates on an orbit whose radius corresponds to the value of the laser field strength. In contrast, the results obtained in the case of the linearly polarized laser field show that the laser makes a significant contribution to the enhancement of the DCS [40,41]. In this case, the electron moves only in perpendicular electric and magnetic fields without any other movement, so that the probability of the electron being scattered with the proton will be greater with respect to the linearly polarized laser field than that corresponding to a circularly polarized laser field.…”

“…To the best of our knowledge, only two articles have addressed the electron-proton scattering, where the proton is not considered to be fixed, in the presence of an electromagnetic field. In 2014 and in a brief report, the recoil effect in relativistic scattering of an electron from a freely movable proton in the presence of a linearly polarized laser field has been investigated in the first Born approximation by Liu and Li [40]. In another recent paper, Wang et al studied the electron scattering from freely movable proton and positive muon µ + in the presence of a radiation field and examined the dependencies of the DCS on the laser field intensity and the electron-impact energy [41].…”

Influence of intense laser fields on measurable quantities in $W^{-}$-boson decay

“…Thus, it cannot be denied that the polarization of the laser field plays an important role in the contrast of the results. The same can be said about the various changes that can occur in the differential cross section in laser-assisted scattering processes [38][39][40] with respect to different polarizations of the laser field. However, this difference in lifetime behavior in both cases of polarization can be widely accepted with reference to the quantum Zeno effect [41,42] or the anti-Zeno effect [43,44], depending on whether the decay is decelerated or accelerated.…”

Relativistic elastic scattering of an electron by a muon in the field of a circularly polarized electromagnetic wave

“…Electron-positron scattering in the field of a light wave was studied in the works [18,19]. Elastic electron-proton scattering in the presence of a circularly [20] or linearly [21,22] polarized laser field has been also reported. In addition to QED processes, many authors have studied some processes of the electroweak theory such as the decay of particles [23,24] and the Higgs-boson production [25] in the presence of a circularly polarized laser field.…”