Novel constraints on neutrino physics beyond the standard model from the CONUS experiment

Abstract

The measurements of coherent elastic neutrino-nucleus scattering (CEνNS) experiments have opened up the possibility to constrain neutrino physics beyond the standard model of elementary particle physics. Furthermore, by considering neutrinoelectron scattering in the keV-energy region, it is possible to set additional limits on new physics processes. Here, we present constraints that are derived from Conus germanium data on beyond the standard model (BSM) processes like tensor and vector non-standard interactions (NSIs) in the neutrino-quark sector, as well as light vector and scalar mediators. Thanks to the realized low background levels in the Conus experiment at ionization energies below 1 keV, we are able to set the world's best limits on tensor NSIs from CEνNS and constrain the scale of corresponding new physics to lie above 360 GeV. For vector NSIs, the derived limits strongly depend on the assumed ionization quenching factor within the detector material, since small quenching factors largely suppress potential signals for both, the expected standard model CEνNS process and the vector NSIs. Furthermore, competitive limits on scalar and vector mediators are obtained from the CEνNS channel at reactor-site which allow to probe coupling constants as low as 5 • 10 −5 of low mediator masses, assuming the currently favored quenching factor regime. The consideration of neutrino-electron scatterings allows to set even stronger constraints for mediator masses below ∼ 1 MeV and ∼ 10 MeV for scalar and vector mediators, respectively.

Dark matter detectors as a novel probe for light new physics

“…3 we compare our present results at 90% C.L. with existing constraints from the analysis of COHERENT-CsI data [23] as well as with constraints coming from the recent CONNIE [28] and CONUS [29] data and the anomalous magnetic moment of the muon reported in Ref. [4].…”

“…Available results can be found from CEνNS analyses in Refs. [23,28,29] and from the interpretation of the XENON1T excess in Ref. [7].…”

“…While the implications of light vector and scalar mediators to the expected signal rates had already been explored at direct detection dark matter experiments [15,16], after the recent observation of coherent elastic neutrino-nucleus scattering (CEνNS) by the COHER-ENT experiment [17][18][19] there has been an intense interest for novel mediator investigations [20][21][22][23][24][25][26][27]. In addition to COHERENT, data-driven constraints also exist from upper limits on CEνNS, placed by the recent CONNIE [28] and CONUS [29] measurements. Phenomenological studies focusing on various U (1) realisations such as the L µ − L τ and B − L guage symmetries have been explored using solar neutrinos [30,31] as well as using supernova neutrinos taking also into account corrections from medium effects [32].…”

“…[39] where their connection to neutrino transition magnetic moments was emphasised. Finally, constraints in the tensor parameter space were extracted from the analysis of COHERENT data [40] and more recently by the CONUS collaboration [29].…”

Direct measurement of the ionization quenching factor of nuclear recoils in germanium in the keV energy range

“…It consists of four 1kg-sized HPGe detectors [7] deployed at the nuclear power plant of Brokdorf (Germany). For CONUS, the quenching factor is not only crucial for the interpretation of the Standard Model neutrino data [23], but it is also the current main systematic uncertainty in the search for new physics [24]. Further experimental determination of this quantity was thus needed to support the on-going and future experimental program as well as to refine the understanding of the stopping process of low energy ions.…”