Probing light mediators and (g − 2)μ through detection of coherent elastic neutrino nucleus scattering at COHERENT

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 sin2θW 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.

Section: Discussionmentioning

confidence: 99%

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

Sierra

Romeri

Papoulias

2022

“…[65], we instead keep X µ as a dynamical field when setting the bounds on g X , using the likelihood from ref. [114] (see also [115,116]).…”

Section: Neutrino Oscillations and Coherent Elastic Neutrino-nucleus ...mentioning

confidence: 99%

On (g − 2)μ from gauged U(1)X

Greljo

Stangl

Thomsen

et al. 2022

We investigate an economical explanation for the (g − 2)μ anomaly with a neutral vector boson from a spontaneously broken U(1)X gauge symmetry. The Standard Model fermion content is minimally extended by 3 right-handed neutrinos. Using a battery of complementary constraints, we perform a thorough investigation of the renormalizable, quark flavor-universal, vector-like U(1)X models, allowing for arbitrary kinetic mixing. Out of 419 models with integer charges not greater than ten, only 7 models are viable solutions, describing a narrow region in model space. These are either Lμ− Lτ or models with a ratio of electron to baryon number close to −2. The key complementary constraints are from the searches for nonstandard neutrino interactions. Furthermore, we comment on the severe challenges to chiral U(1)X solutions and show the severe constraints on a particularly promising such candidate.

“…For the analysis of the COHERENT CsI and Ar data we follow closely the strategy explained in detail in ref. [69]. We obtained information on all the quantities used from refs.…”

Section: Coherentmentioning

confidence: 99%

“…Differently from ref. [69], in the CsI analysis we also include the contribution of the electron-neutrino scattering, as stated in section 2. In each electron-recoil energy-bin i, the theoretical ES event number N ES i is given by…”

Section: Coherentmentioning

confidence: 99%

Impact of the Dresden-II and COHERENT neutrino scattering data on neutrino electromagnetic properties and electroweak physics

Corona

Cadeddu

Cargioli

et al. 2022

Self Cite

Coherent elastic neutrino-nucleus scattering (CEνNS) represents a powerful tool to investigate key electroweak physics parameters and neutrino properties since its first observation in 2017 by the COHERENT experiment exploiting the spallation neutron source at Oak Ridge National Laboratory. In light of the recent detection of such a process with antineutrinos produced by the Dresden-II reactor scattering off a germanium detector, we revisit the limits so far set on the neutrino magnetic moments, charge radii and millicharges as well as on the weak mixing angle. In order to do so, we also include the contribution of elastic neutrino-electron scattering, whose effect becomes non negligible in some beyond the Standard Model theories. By using different hypotheses for the germanium quenching factor and the reactor antineutrino flux, we provide a measurement of the weak mixing angle at the low-energy scale of the Dresden-II reactor experiment and, thanks to a combined analysis with the latest cesium iodide and argon data set released by the COHERENT Collaboration, we deliver updated limits for the neutrino electromagnetic properties. Interestingly, we are able to set a new best upper limit on the electron neutrino charge radius and significantly improve the other CEνNS-related limits on the neutrino electric charge and magnetic moment.