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 construct models of leptons based on S 4 family symmetry combined with a generalised CP symmetry H CP . We show how the flavon potential can spontaneously break the symmetry S 4 ⋊ H CP down to Z 2 × H ν CP in the neutrino sector, where the choice of preserved CP symmetry H ν CP is controlled by free (real) parameters in the flavon potential. We propose two realistic models of this kind, one at the effective level and one at the renormalisable level. Both models predict trimaximal lepton mixing with CP being either fully preserved or maximally broken, with the intermediate possibility forbidden by the structure of the models. *
Assuming that the observed pattern of 3-neutrino mixing is related to the existence of a (lepton) flavour symmetry, corresponding to a non-Abelian discrete symmetry group G f , and that G f is broken to specific residual symmetries G e and G ν of the charged lepton and neutrino mass terms, we derive sum rules for the cosine of the Dirac phase δ of the neutrino mixing matrix U . The residual symmetries considered are: i) G e = Z 2 and G ν = Z n , n > 2 or Z n × Z m , n, m ≥ 2; ii) G e = Z n , n > 2 or Z n × Z m , n, m ≥ 2 and G ν = Z 2 ; iii) G e = Z 2 and G ν = Z 2 ; iv) G e is fully broken and G ν = Z n , n > 2 or Z n × Z m , n, m ≥ 2; and v) G e = Z n , n > 2 or Z n × Z m , n, m ≥ 2 and G ν is fully broken. For given G e and G ν , the sum rules for cos δ thus derived are exact, within the approach employed, and are valid, in particular, for any G f containing G e and G ν as subgroups. We identify the cases when the value of cos δ cannot be determined, or cannot be uniquely determined, without making additional assumptions on unconstrained parameters. In a large class of cases considered the value of cos δ can be unambiguously predicted once the flavour symmetry G f is fixed. We present predictions for cos δ in these cases for the flavour symmetry groups G f = S 4 , A 4 , T and A 5 , requiring that the measured values of the 3-neutrino mixing parameters sin 2 θ 12 , sin 2 θ 13 and sin 2 θ 23 , taking into account their respective 3σ uncertainties, are successfully reproduced.Within the approach employed this sum rule is exact. 5 It is valid, in particular, for any value of the angle θ ν 23 [14]. 6 In [11], by using the sum rule in eq. (12), predictions for cos δ and δ were obtained in the TBM, BM, GRA, GRB and HG cases for the best fit values of sin 2 θ 12 , sin 2 θ 23 and sin 2 θ 13 . The results thus obtained permitted to conclude that a sufficiently precise measurement of cos δ would allow to discriminate between the different forms ofŨ ν considered.Statistical analyses of predictions of the sum rule given in eq. (12) i) for δ and for the J CP factor, which determines the magnitude of CP-violating effects in neutrino oscillations [38], using the current uncertainties in the determination of sin 2 θ 12 , sin 2 θ 13 , sin 2 θ 23 and δ from [28], and ii) for cos δ using the prospective uncertainties on sin 2 θ 12 , sin 2 θ 13 and sin 2 θ 23 , were performed in [13] for the five symmetry forms -BM (LC), TBM, GRA, GRB and HG -of U ν .In [14] we extended the analyses performed in [11,13] by obtaining sum rules for cos δ for the following forms of the matricesŨ e andŨ ν : 7 A.Ũ ν = R 23 (θ ν 23 )R 12 (θ ν 12 ) with θ ν 23 = −π/4 and θ ν 12 as dictated by TBM, BM, GRA, GRB or HG mixing, and i)Ũ e = R −1 13 (θ e 13 ), ii)Ũ e = R −1 23 (θ e 23 )R −1 13 (θ e 13 ), and iii)Ũ e = R −1 13 (θ e 13 )R −1 12 (θ e 12 ); B.Ũ ν = R 23 (θ ν 23 )R 13 (θ ν 13 )R 12 (θ ν 12 ) with θ ν 23 , θ ν 13 and θ ν 12 fixed by arguments associated with symmetries, and iv)Ũ e = R −1 12 (θ e 12 ), and v)Ũ e = R −1 13 (θ e 13 ).The sum rules for ...
The deep underground neutrino experiment (DUNE), a 40-kton underground liquid argon time projection chamber experiment, will be sensitive to the electron-neutrino flavor component of the burst of neutrinos expected from the next Galactic core-collapse supernova. Such an observation will bring unique insight into the astrophysics of core collapse as well as into the properties of neutrinos. The general capabilities of DUNE for neutrino detection in the relevant few- to few-tens-of-MeV neutrino energy range will be described. As an example, DUNE’s ability to constrain the $$\nu _e$$ ν e spectral parameters of the neutrino burst will be considered.
The sensitivity of the Deep Underground Neutrino Experiment (DUNE) to neutrino oscillation is determined, based on a full simulation, reconstruction, and event selection of the far detector and a full simulation and parameterized analysis of the near detector. Detailed uncertainties due to the flux prediction, neutrino interaction model, and detector effects are included. DUNE will resolve the neutrino mass ordering to a precision of 5$$\sigma $$ σ , for all $$\delta _{\mathrm{CP}}$$ δ CP values, after 2 years of running with the nominal detector design and beam configuration. It has the potential to observe charge-parity violation in the neutrino sector to a precision of 3$$\sigma $$ σ (5$$\sigma $$ σ ) after an exposure of 5 (10) years, for 50% of all $$\delta _{\mathrm{CP}}$$ δ CP values. It will also make precise measurements of other parameters governing long-baseline neutrino oscillation, and after an exposure of 15 years will achieve a similar sensitivity to $$\sin ^{2} 2\theta _{13}$$ sin 2 2 θ 13 to current reactor experiments.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.