The physics potential of a reactor neutrino experiment with Skipper CCDs: Measuring the weak mixing angle

Abstract

We analyze in detail the physics potential of an experiment like the one recently proposed by the vIOLETA collaboration: a kilogram-scale Skipper CCD detector deployed 12 meters away from a commercial nuclear reactor core. This experiment would be able to detect coherent elastic neutrino nucleus scattering from reactor neutrinos, capitalizing on the exceptionally low ionization energy threshold of Skipper CCDs. To estimate the physics reach, we elect the measurement of the weak mixing angle as a case study. We choose a realistic benchmark experimental setup and perform variations on this benchmark to understand the role of quenching factor and its systematic uncertainties, background rate and spectral shape, total exposure, and reactor antineutrino flux uncertainty. We take full advantage of the reactor flux measurement of the Daya Bay collaboration to perform a data driven analysis which is, up to a certain extent, independent of the theoretical uncertainties on the reactor antineutrino flux. We show that, under reasonable assumptions, this experimental setup may provide a competitive measurement of the weak mixing angle at few MeV scale with neutrino-nucleus scattering.

The physics potential of a reactor neutrino experiment with Skipper CCDs: measuring the weak mixing angle

“…This scenario corresponds to the Atucha II Nuclear Power plant, located at Lima, a town ∼100 km away from Buenos Aires capital city in Argentina. We will consider a data taking period of 3 years [5]. We assume 45 days of reactor off data taking per year, as in Ref.…”

“…Nevertheless, since the experimental setup consists on a set of Skipper-CCD detectors near a commercial nuclear reactor, the overburden is only set by the concrete over the detector and the power plant concrete dome. We thus adopt a conservative estimate of the background rate of 1 kdru (1 differential rate unit, or dru, is 1 event per day-keV-kg) [79].…”

“…A novel technology that has yet to be exploited for CEvNS is that of Skipper charged coupled devices, or Skipper-CCDs. A basic explanation of the Skipper-CCD technology can be found in our previous work [5], but we highlight here two key features of these detectors: (1) Skipper-CCDs are endowed with single-electron counting capability [6,7], which allows them to observe energy deposits as low as a few electronvolts; and (2) the readout time for this technology is relatively large, about 1 millisecond per 15 µm by 15 µm pixel, which makes impractical to use active vetos in order to reduce cosmic ray backgrounds.…”

Search for coherent elastic neutrino-nucleus scattering at a nuclear reactor with CONNIE 2019 data

“…The lower momentum exchange in CEνNS from reactor neutrinos eliminates the dependence on the nuclear form factor, with F (q) ∼ 1 in Eq. 1.1, and enhances the sensitivity to potential effects predicted in new physics scenarios, such as an anomalous magnetic moment [6] or millicharge [7] of the neutrino, light sterile neutrinos [8], weak mixing angle [9,10], and non-standard interactions of neutrinos such as light mediators [11,12].…”

SENSEI: Characterization of Single-Electron Events Using a Skipper-CCD

“…The development of the Skipper-CCD [6], with its deep sub-electron read-out noise and resulting ability to detect events producing only a single photon or a single electron, has revolutionized the search for coherent neutrino scattering and dark matter particles, since these produce events typically containing only one or a few ionized electrons [7,8]. The first science results from data collected with a single Skipper-CCD have already been presented in [9][10][11], and the construction of large-mass detectors for both neutrino and dark matter particles searches is underway or planned [11][12][13][14].…”