Physics with beam tau-neutrino appearance at DUNE

Abstract

We explore the capabilities of the upcoming Deep Underground Neutrino Experiment (DUNE) to measure ν τ charged-current interactions and the associated oscillation probability P (ν µ → ν τ ) at its far detector, concentrating on how such results can be used to probe neutrino properties and interactions. DUNE has the potential to identify significantly more ν τ events than all existing experiments and can use this data sample to nontrivially test the three-massive-neutrinos paradigm by providing complementary measurements to those from the ν e appearance and ν µ disappearance channels. We further discuss the sensitivity of the ν τ appearance channel to several hypotheses for the physics that may lurk beyond the three-massive-neutrinos paradigm: a non-unitary lepton mixing matrix, the 3 + 1 light neutrinos hypothesis, and the existence of non-standard neutral-current neutrino interactions. Throughout, we also consider the relative benefits of the proposed high-energy tune of the Long-Baseline Neutrino Facility (LBNF) beam-line.

Tau neutrinos at DUNE: New strategies, new opportunities

“…Ultimately, several physics analyses could benefit from applying our tool chain with realistic detector effects and a treatment of systematic uncertainties. Amongst those are ν τ -nucleus interaction measurements [6,21]; violations of unitarity in the leptonic mixing matrix [23,25,[48][49][50]; nonstandard neutrinos interactions in neutrino production, detection and propagation [51]; sterile neutrino searches [52][53][54][55]; and general consistency tests of the three neutrino oscillation paradigm [24,28]. In our work we demonstrate that the tau-optimized beam significantly enhances the prospects of tau neutrino measurements at DUNE.…”

“…Despite such difficulties, upcoming multipurpose neutrino experiments, such as DUNE [14], are well posed to detect tau neutrinos given their large fiducial volume, powerful neutrino beam and exquisite track reconstruction capability. There have been a number of works which explore the tau neutrino sector including pioneering proposals for observing ν τ at beam dump experiments [15] and the subsequent experimental search by NOMAD [16], polarization effects on τ decay products for atmospheric and beam ν τ searches [17][18][19][20][21], optimization of cuts on τ decay products in the DUNE beam neutrino sample [22], tests of unitarity and patterns of leptonic mixing [23][24][25] and beyond the Standard Model physics probes with ν τ measurements [26][27][28][29].…”

Quasi-Dirac neutrino oscillations at DUNE and JUNO

“…This possibility has been recently discussed in Ref. [89,90]. If neutrinos are quasi-Dirac particles, β P αβ < 1, with β = {e, µ, τ }.…”

Neutrino non-standard interactions: A status report

“…These were mostly interested in new physics impacting the ν µ -disapparance channel and the ν e -appearance channel in the DUNE far detector. For results including ν τ -appearance, see [259]. Simulations involving Hyper-Kamiokande were also considered, mostly in the context of elucidating the nature of the new phenomenon that manifested itself in long-baseline oscillations.…”