Consequences of the Dresden-II reactor data for the weak mixing angle and new physics

Abstract

The Dresden-II reactor experiment has recently reported a suggestive evidence for the observation of coherent elastic neutrino-nucleus scattering, using a germanium detector. Given the low recoil energy threshold, these data are particularly interesting for a low-energy determination of the weak mixing angle and for the study of new physics leading to spectral distortions at low momentum transfer. Using two hypotheses for the quenching factor, we study the impact of the data on: (i) The weak mixing angle at a renormalization scale of ∼ 10 MeV, (ii) neutrino generalized interactions with light mediators, (iii) the sterile neutrino dipole portal. The results for the weak mixing angle show a strong dependence on the quenching factor choice. Although still with large uncertainties, the Dresden-II data provide for the first time a determination of sin 2 θ W at such scale using coherent elastic neutrino-nucleus scattering data. Tight upper limits are placed on the light vector, scalar and tensor mediator scenarios. Kinematic constraints implied by the reactor anti-neutrino flux and the ionization energy threshold allow the sterile neutrino dipole portal to produce up-scattering events with sterile neutrino masses up to ∼ 8 MeV. In this context, we find that limits are also sensitive to the quenching factor choice, but in both cases competitive with those derived from XENON1T data and more stringent that those derived with COHERENT data, in the same sterile neutrino mass range.

New reactor data improves robustness of neutrino mass ordering determination

“…In fig. 2 we show the constraints from the Dresden-II data reinterpreted from [85] along with the LMA-Dark Dresden-II FIG. 2.…”

“…The constraints from the recent Dresden-II data on new physics scenarios have been analyzed in [83][84][85][86]. We translate the results from [85] to arrive at the excluded regions in the |g q g νe |−M Z parameter space.…”

“…The constraints from the recent Dresden-II data on new physics scenarios have been analyzed in [83][84][85][86]. We translate the results from [85] to arrive at the excluded regions in the |g q g νe |−M Z parameter space. To quantify the dependence of the results on the quenching factor, the relation between nuclear recoil energy to electronic recoils, the results are derived for two different quenching factors: the first is based on a quenching factor determined using iron-filtered monochromatic neutrons provided in [52,87], and the second is based on a modified Lindhard factor [88].…”

Snowmass White Paper: Beyond the Standard Model effects on Neutrino Flavor

“…If the mediator also couples to quarks, it can be tested by Coherent Elastic ν Nucleus Scattering (CEνNS) measurements at the COHERENT experiment [147,151,156,[178][179][180][181][182][183]. Relevant limits on light mediators have also been obtained from CEνNS searches using reactor neutrinos at CONUS [184], CONNIE [185], and the Dresden-II reactor experiment [147,148,186]. Proposals for similar searches have been put forward at the European Spallation Source [157,187] and at Los Alamos National Laboratory [188].…”

Probing neutrino magnetic moments and the XENON1T excess with coherent elastic solar neutrino scattering

“…CEνNS experiments based on the neutrino fluxes from man-made sources including the spallation neutron source [28,29] and nuclear reactors [30][31][32][33][34][35] are promising on providing competitive constraints on a series of the new physics theory. On the other hand, there have already been intensive interests in the observation of astrophysical neutrino fluxes through the CEνNS process, which could be a new probe to supernovae [36][37][38][39][40][41], the collapsing supermassive stars [42] and the primordial black holes [43].…”