New Physics Probes: Atomic Parity Violation, Polarized Electron Scattering and Neutrino-Nucleus Coherent Scattering

Abstract

Atomic Parity Violation (APV) is usually quantified in terms of the weak nuclear charge QW of a nucleus, which depends on the coupling strength between the atomic electrons and quarks. In this work, we review the importance of APV to probing new physics using effective field theory. Furthermore, using SU (2) invariance, we correlate our findings with those from neutrino-nucleus coherent scattering. Moreover, we investigate signs of parity violation in polarized electron scattering and show how precise measurements on the Weinberg angle, sin θW , will give rise to competitive bounds on light mediators over a wide range of masses and interactions strength. Lastly, apply our bounds to several models namely, Dark Z, Two Higgs Doublet Model-U (1)X and 3-3-1, considering both light and heavy mediator regimes.

Wolfenstein potentials for neutrinos induced by ultra-light mediators

“…Near the surface (r ≈ R) the shortrange potential (green curve) is roughly half the standard Wolfenstein potential (the plateau of this curve), as expected from Eq. (27). When m A decreases, it becomes smoother (yellow line).…”

“…For m A,φ O(10 2 ) keV, g 2 /m 2 A G F and y 2 /m 2 φ G F have been excluded by numerous laboratory experiments including the elastic neutrino-electron scattering [25][26][27], neutrino-nucleus scattering [28][29][30], fixed target experiments [31][32][33], collider searches [34,35], etc. For 1 eV m A,φ 10 2 keV, the astrophysical observations provide much stronger constraints.…”

Implications of the first detection of coherent elastic neutrino-nucleus scattering (CEvNS) with Liquid Argon

“…It has been recently shown [53] that low energy scattering experiments are favorable facilities for probing the existence of light mediators, of both vector [54] and scalar [29] type. Indeed, by focusing on the Z predicted within the context of string-inspired E 6 and Left-Right symmetries, the authors of Ref.…”

Constraints on new physics from an improved calculation of parity violation in $^{133}$Cs

“…Direct experimental signature suggests its value to be less than 0.2 GeV [25]. A fairly recent manuscript [24] suggests that the limit on an effective electron-nucleus coupling describing new physics beyond the SM expressed as f ef f Vq Λ 2 < 4.38699 × 10 −9 GeV −2 with a new energy scale Λ and emphasizes that the bound on the effective couplings inferred from APV is more stringent than the ones from the neutrino-nucleus coherent scattering processes.…”