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The SuperCDMS experiment is designed to directly detect weakly interacting massive particles (WIMPs) that may constitute the dark matter in our Galaxy. During its operation at the Soudan Underground Laboratory, germanium detectors were run in the CDMSlite mode to gather data sets with sensitivity specifically for WIMPs with masses <10 GeV=c 2 . In this mode, a higher detector-bias voltage is applied to amplify the phonon signals produced by drifting charges. This paper presents studies of the experimental noise and its effect on the achievable energy threshold, which is demonstrated to be as low as 56 eV ee (electron equivalent energy). The detector-biasing configuration is described in detail, with analysis corrections for voltage variations to the level of a few percent. Detailed studies of the electric-field geometry, and the resulting successful development of a fiducial parameter, eliminate poorly measured events, yielding an energy resolution ranging from ∼9 eV ee at 0 keV to 101 eV ee at ∼10 keV ee . New results are derived for astrophysical uncertainties relevant to the WIMP-search limits, specifically examining how they are affected by variations in the most probable WIMP velocity and the Galactic escape velocity. These variations become more important for WIMP masses below 10 GeV=c 2 . Finally, new limits on spin-dependent low-mass WIMP-nucleon interactions are derived, with new parameter space excluded for WIMP masses ≲3 GeV=c 2 .

The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber with an active volume of 7.2× 6.1× 7.0 m3. It is installed at the CERN Neutrino Platform in a specially-constructed beam that delivers charged pions, kaons, protons, muons and electrons with momenta in the range 0.3 GeV/c to 7 GeV/c. Beam line instrumentation provides accurate momentum measurements and particle identification. The ProtoDUNE-SP detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment, and it incorporates full-size components as designed for that module. This paper describes the beam line, the time projection chamber, the photon detectors, the cosmic-ray tagger, the signal processing and particle reconstruction. It presents the first results on ProtoDUNE-SP's performance, including noise and gain measurements, dE/dx calibration for muons, protons, pions and electrons, drift electron lifetime measurements, and photon detector noise, signal sensitivity and time resolution measurements. The measured values meet or exceed the specifications for the DUNE far detector, in several cases by large margins. ProtoDUNE-SP's successful operation starting in 2018 and its production of large samples of high-quality data demonstrate the effectiveness of the single-phase far detector design.

We report on νe andνe appearance in νµ andνµ beams using the full MINOS data sample. The comparison of these νe andνe appearance data at a 735 km baseline with θ13 measurements by reactor experiments probes δ, the θ23 octant degeneracy, and the mass hierarchy. This analysis is the first use of this technique and includes the first accelerator long-baseline search forνµ →νe. Our data disfavor 31% (5%) of the three-parameter space defined by δ, the octant of the θ23, and the mass hierarchy at the 68% (90%) C.L. We measure a value of 2sin 2 (2θ13)sin 2 (θ23) that is consistent with reactor experiments. 2PACS numbers: 14.60. Pq, 14.60.Lm, The neutrino oscillation phenomenon is successfully modeled by a theory of massive neutrino eigenstates that are different from the neutrino flavor eigenstates. These sets of eigenstates are related by the PMNS matrix [1] which is commonly parameterized by three angles, θ ij , and a CP-violating phase, δ.The values of θ 12 and θ 23 have been measured [2-4] with indications that θ 23 is not maximal [5][6][7]. The final angle, θ 13 , is now known to have a nonzero value from measurements by reactor experiments [8][9][10], the measurement by the T2K [11] accelerator experiment, and from earlier MINOS results [12,13].Despite these accomplishments, the value of δ is still unknown, as is the ordering of the neutrino masses, which is referred to as the neutrino mass hierarchy. Much of the attention in the neutrino community is now focused on resolving these unknowns. The mass hierarchy is not only a fundamental property of neutrinos but also has a direct impact on the ability of neutrinoless double beta decay searches to state definitively whether the neutrino is its own antiparticle [14]. Reactor experiments make a pure measurement of θ 13 , whereas the ν µ → ν e and ν µ →ν e appearance probabilities measured by accelerator experiments such as MINOS depend on the value of δ and sin 2 (θ 23 ). In addition, the long-baseline of MI-NOS means that interactions between neutrinos and the matter of the Earth make the appearance probabilities dependent on the neutrino mass hierarchy [15,16].We report the result from the search for ν e (ν e ) appearance in a ν µ (ν µ ) beam using the full MINOS data sample. This result uses an exposure of 10.6 × 10 20 protons-ontarget taken with a ν beam and an exposure of 3.3 × 10 20 protons-on-target taken with aν beam. The neutrino sample is 30% larger than the sample used for the previous MINOS results on this topic [13]. This analysis represents the first long-baseline search forν µ →ν e appearance and places new constraints on θ 13 and on a combination of δ, θ 23 , and the neutrino mass hierarchy.In the MINOS experiment [17], neutrino oscillation is studied with the NuMI beamline [18] by measuring neutrino interactions in two detectors. The Near Detector (ND), which has a fiducial mass of 29 tons, is at a distance of 1.04 km from the production target and is used to determine the composition of the beam before the neutrinos have oscillated. The Far Detector...