Theory of Neutrino-Atom Collisions: The History, Present Status, and BSM Physics

Abstract

An overview of the current theoretical studies on neutrino-atom scattering processes is presented. The ionization channel of these processes, which is studied in experiments searching for neutrino magnetic moments, is brought into focus. Recent developments in the theory of atomic ionization by impact of reactor antineutrinos are discussed. It is shown that the stepping approximation is well applicable for the data analysis practically down to the ionization threshold.

Electromagnetic properties of massive neutrinos in low-energy elastic neutrino-electron scattering

“…Notable deviations of the weak and magnetic cross sections from the stepping formula (34) are found only close to the ionization threshold [29,30], where the cross-section values decrease relative to the free-electron approximation. The latter behavior is attributed to the effects of electron-electron correlations in atoms [28].…”

“…The stepping approximation was first introduced in Ref. [26] on the basis of numerical calculations for the case of an iodine atomic target, and later it was supported by a general theoretical analysis [27,28]. Notable deviations of the weak and magnetic cross sections from the stepping formula (34) are found only close to the ionization threshold [29,30], where the cross-section values decrease relative to the free-electron approximation.…”

Electromagnetic interactions of neutrinos in processes of low-energy elastic neutrino-electron scattering

“…Notable deviations of the weak and magnetic cross sections from the stepping formula (18) are found only close to the ionization threshold [16,17], where the cross-section values decrease relative to the free-electron approximation. The latter behavior is attributed to the effects of electron-electron correlations in atoms [12]. The impact of electron-binding effects on the angular differential cross section dσ/dΩ e is, in general, more involved.…”

“…The stepping approximation was first introduced in Ref. [15] on the basis of numerical calculations for the case of an iodine atomic target, and later it was supported by a general theoretical analysis [9,12]. Notable deviations of the weak and magnetic cross sections from the stepping formula (18) are found only close to the ionization threshold [16,17], where the cross-section values decrease relative to the free-electron approximation.…”

Neutrino magnetic moment, millicharge and charge radius

“…For the recent reviews on the neutrino electromagnetic properties and related problems see [3][4][5][6][7]. In this contribution we give a very brief overview of the neutrino magnetic moment, millicharge and charge radius and discuss how they can manifest themselves in neutrino-nuclues coherent scattering.…”