Probing neutrino coupling to a light scalar with coherent neutrino scattering

Abstract

Large neutrino event numbers in future experiments measuring coherent elastic neutrino nucleus scattering allow precision measurements of standard and new physics. We analyze the current and prospective limits of a light scalar particle coupling to neutrinos and quarks, using COHERENT and CONUS as examples. Both lepton number conserving and violating interactions are considered. It is shown that current (future) experiments can probe for scalar masses of a few MeV couplings down to the level of 10 −4 (10 −6 ). Scalars with masses around the neutrino energy allow to determine their mass via a characteristic spectrum shape distortion. Our present and future limits are compared with constraints from supernova evolution, Big Bang nucleosynthesis and neutrinoless double beta decay. We also outline UV-complete underlying models that include a light scalar with coupling to quarks for both lepton number violating and conserving coupling to neutrinos. II. LIGHT SCALAR INTERACTIONS IN COHERENT NEUTRINO-NUCLEUS SCATTERINGIn this section, we first introduce the possible interactions of neutrinos with quarks (or nuclei) mediated by a light scalar boson and then discuss the corresponding cross section of coherent neutrino-nucleus scattering. A. New scalar interactionsWe consider a scalar field denoted by φ which couples to neutrinos. There are two possibilities for such coupling, namely lepton number violating (LNV) and conserving (LNC) couplings. The latter possibility requires the presence arXiv:1802.05171v1 [hep-ph]

Constraining sterile neutrino cosmology with terrestrial oscillation experiments

“…We estimate the sensitivity of the CONUS experiment to oscillations involving a sterile neutrino following the procedures employed in Refs. [90,91]; we present this analysis fully in Appendix B, but provide some relevant details here. We consider two benchmark configurations for CONUS.…”

“…We form the following χ 2 in order to probe the sensitivity of these experiments to a sterile neutrino, following Ref. [90]:…”

“…For our benchmark analysis of CONUS, we take ∆t = 1 year, and n f to be consistent with 4.0 kg of natural germanium; the isotopic abundances are shown in Table III. Because the ionization detection threshold is 0.3 keV and the quenching factor is ∼ 0.25, the minimum recoil energy is 1.2 keV [90], and the recoil spectrum is binned in 0.05-keV increments. The normalization and shape uncertainties are taken to be 2% and 1%, respectively.…”

“…Furthermore, we assume a recoil threshold of 0.1 keV can be attained and that improvements in reactor antineutrino flux predictions can drive down the normalization and shape uncertainties to 0.5% and 0.1%, respectively. For both configurations, we take the background rate to be 1 count/(day·keV·kg) [90], even in the low-recoil regime and for the larger target.…”

Probing new neutral gauge bosons with CEνNS and neutrino-electron scattering

“…New constraints have been placed on non-standard and generalized interactions [26][27][28][29], nuclear physics parameters [30][31][32], neutrino electromagnetic properties [33,34] and sterile neutrinos [35][36][37]. It has been noted [38][39][40][41][42][43][44][45][46] that light mediators may be accessible to CEνNS experiments, providing information that is complementary to what can be achieved from high-energy and/or precision measurements. Constraints on the Z parameters from CEνNS have been reported in Refs.…”