Modern neutrino detectors, particularly the large liquid argon time projection chambers (LAr TPCs) at SBN and DUNE, provide an unprecedented amount of information about GeV-scale interactions. By taking advantage of the excellent spatial and calorimetric resolution as well as the low tracking thresholds provided by LAr TPCs, we present a novel method of estimating the neutrino energy in neutral current interactions. This method has potential implications for the search for a sterile neutrino; it allows for the potential observation of spectral distortions due to sterile neutrino-induced oscillations in the neutral current neutrino energy spectrum. As an example, we use this method to perform an analysis of the statistics-only sensitivity to sterile neutrinos in the neutral current channel at SBN under a 3+1 model.
Reactor neutrinos have been an intense field of investigation for the last decade. Two anomalies are discussed in this document. First, a status of the sterile neutrino searches by STEREO, PROSPECT and DANSS is presented. The best-fit parameters of active-to-sterile oscillations from the Reactor Antineutrino Anomaly are strongly rejected by these experiments. Second, the analyses of the shape anomaly ("5 MeV bump") by STEREO and PROSPECT, both using a virtually pure-$^{235}$U neutrino flux, are detailed. Results show a significant excess of events at 5-6 MeV and indicate that the bump observed…
I describe two new searches for sterile neutrino oscillations from the MINOS and Daya Bay experiments. MINOS looked for evidence through muon neutrino disappearance with data collected from the NuMI neutrino beam. Daya Bay searched for evidence through electron antineutrino disappearance using data collected from nuclear reactors. I explain how the MINOS and Daya Bay searches were combined to produce constraints on the same phase space as LSND and MiniBooNE. Finally, I present the status of the sterile neutrino search using data from MINOS+.
Search for New Physics beyond the Standard Model is the main direction in particle physics nowadays. There are several experimental hints of New Physics. The most statistically significant (5-6$σ$) are the hints of eV mass scale sterile neutrinos. They come from antineutrino disappearance in reactor experiments, $ν_e$ disappearance in experiments with very powerful radioactive sources, and electron (anti)neutrino appearance in the muon (anti)neutrino beams. Very important results in this field were obtained in 2021 by the BEST, MicroBooNE, and Neutrino-4 collaborations as well as by several ot…
Anomalies in short baseline experiments have been interpreted as evidence for additional neutrino mass states with large mass splittings from the known, active flavors. This explanation mandates a corresponding signature in the muon neutrino disappearance channel, which has yet to be observed. Searches for muon neutrino disappearance at the IceCube neutrino telescope presently provide the strongest limits in the space of mixing angles for eV-scale sterile neutrinos. This proceeding for the Very Large Volume Neutrino Telescopes (VLVnT) Workshop summarizes the IceCube analyses that have searched…
Several anomalies are discussed in neutrino physics, linked to the possible existence of light sterile neutrinos. These sterile neutrinos would not interact weakly, but they could leave an imprint in various measurements, such as neutrino oscillation experiments or precise measurements of beta decay spectra. Global analyses of neutrino oscillation data suggest sterile neutrinos with a mass in the eV range, but reveal at the same time tensions with the observed neutrino anomalies. In the next years several experiments will test the sterile neutrino hypothesis with masses in the eV range with pr…
In the last decades, the results from a number of short-baseline neutrino experiments and the reanalysis of previous reactor experiments with updated antineutrino fluxes suggest some incompatibility with the standard three-neutrino model. A possible solution to these anomalies is the existence of neutrinos that do not interact via the electroweak force, known as sterile neutrinos. The existence of sterile neutrinos can be investigated with the T2K Experiment. Here we present a search for the disappearance of electron neutrinos over a baseline of 280 m using the T2K off-axis near detector. The …
The Precision Reactor Oscillation and Spectrum Experiment (PROSPECT) performs a precision measurement of reactor antineutrinos through inverse beta decay at a baseline range of 7-9 m from the core of the High Flux Isotope Reactor (HFIR). The single, movable detector has a segmented design of 154 optically separated individual segments that serves multiple purposes. Segments, filled with 6Li-loaded liquid scintillator, cover a range of baselines from the reactor core and allow precise event localization. A reactor-model independent search of eV2-scale sterile neutrino oscillations is achieved b…
We investigate features of the sterile neutrinos in the presence of a light gauge boson $X^μ$ that couples to the neutrino sector. The novel bounds on the active-sterile neutrino mixings $| U_{\ell 4} |^2$, especially for tau flavor ($l = τ$), from various collider and fixed target experiments are explored. Also, taking into account the additional decay channel of the sterile neutrino into a light gauge boson ($ν_4 \to ν_\ell e^+ e^-$), we explore and constrain a parameter space for low energy excess in neutrino oscillation experiments.
Two anomalies at nuclear reactors, one related to the absolute antineutrino flux, one related to the antineutrino spectral shape, have drawn special attention to the field of reactor neutrino physics during the past decade. Numerous experimental efforts have been launched to investigate the reliability of flux models and to explore whether sterile neutrino oscillations are at the base of the experimental findings. This review aims to provide an overview on the status of experimental searches at reactors for sterile neutrino oscillations and measurements of the antineutrino spectral shape in mi…
Tagged kaon beams are attractive neutrino sources, which would provide flavor pure $ν_e$-beams with exactly measured normalization. We point out that this also leads to an anti-tagged flavor pure $ν_μ$-beam, with equally well known normalization. Exposing a 1 kt liquid argon detector at a baseline of 1 km to this combination of unique beams allows to decisively test recent indications by IceCube and Neutrino-4 of sterile neutrino oscillations in the multi-eV range.
For a long time there were 3 main experimental indications in favor of the existence of sterile neutrinos: $\bar{ν_e}$ appearance in the $\bar{ν_μ}$ beam in the LSND experiment, $\bar{ν_e}$ flux deficit in comparison with theoretical expectations in reactor experiments, and $ν_e$ deficit in calibration runs with radioactive sources in the Ga solar neutrino experiments SAGE and GALEX. All three problems can be explained by the existence of sterile neutrinos with the mass square difference in the ballpark of $1~\mathrm{eV^2}$. Recently the MiniBooNE collaboration observed electron (anti)neutrino…
Superluminal neutrinos are expected to lose energy due to bremstrauhlung. It is dominated by e+e--pair production if kinematically allowed. The same signature was used in searches for 3-body decays of hypothetical heavy sterile neutrinos. From the absence of these processes in CERN PS191 and CHARM experiments we set upper limits on the neutrino velocity in the energy range from 0.2 GeV to 280 GeV. Our limits are well below the neutrino velocity favored by the recent OPERA results. For energy-independent neutrino velocity the limits obtained in this paper are stronger than those coming from ICA…
We summarize the status of SM Higgs boson searches at the Fermilab Tevatron performed by the CDF and DØcollaborations, with an emphasis on measurements at large Higgs mass, and derive sensitivity prospects for the upcoming increase in integrated luminosity.
A number of anomalous results in short-baseline oscillation may hint at the existence of one or more light sterile neutrino states in the eV mass range and have triggered a wave of new experimental efforts to search for a definite signature of oscillations between active and sterile neutrino states. The present paper aims to provide a comprehensive review on the status of light sterile neutrino searches in mid-2019: we discuss not only the basic experimental approaches and sensitivities of reactor, source, atmospheric, and accelerator neutrino oscillation experiments but also the complementary…
Sterile neutrinos with masses in the range (1-100) GeV, have been searched for in a variety of experiments. Here, we discuss the prospects to search for sterile neutrinos at the LHC using displaced vertices. Two different cases are discussed: (i) the standard model extended with sterile neutrinos and (ii) right-handed neutrinos in a left-right symmetric extension of the standard model. A dedicated displaced vertex search will allow to probe parts of the parameter space not accessible to other searches, but will require large luminosity in both cases.
Light sterile neutrinos have been motivated by anomalies observed in short-baseline neutrino experiments.Among them, radioactive-source and reactor experiments have provided evidence and constraints, respectively, for electron neutrino disappearance compatible with an eV-scale neutrino. The results from these observations are seemingly in conflict. This letter brings into focus the assumption that the neutrino wave packet can be approximated as a plane wave, which is adopted in all analyses of such experiments. We demonstrate that the damping of oscillations, e.g., due to a finite wave packet …
We study discovery prospects for long-lived sterile neutrinos at the LHC with multitrack displaced vertices, with masses below the electroweak scale. We reinterpret current displaced vertex searches making use of publicly available, parametrized selection efficiencies for modeling the detector response to displaced vertices. We focus on production of right-handed $W_{R}$ bosons and neutrinos $N$ in a left-right symmetric model, and find poor sensitivity. After proposing a different trigger strategy (considering the prompt lepton accompanying the neutrino displaced vertex) and optimized cuts in…
We present the recent prospects and strategies of the ATLAS and CMS experiments in the search for signatures of Supersymmetry. The emphasis is placed on standard signatures with missing transverse energy and on the initial data taking periods.
An overview on the prospects for Higgs Boson searches with the CMS detector is presented. Projections have been made to estimate the potential to a possible discovery or exclusion of the Higgs Boson during the run at a center of mass energy of 7 TeV at the LHC, with a recorded integrated luminosity of approximately 1 fb-1, conditions expected by the end of 2011
Possible mixing of the active and sterile neutrinos has been considered both in the single Delta m^2 approximation and in the case of more than one Delta m^2. We perform global fit of the available solar neutrino data with free boron neutrino flux in the single Delta m^2 context. The best fit value corresponds to zero fraction of sterile component eta=0. We get the upper bounds: eta<0.26 (0.64) at 1σ(3 sigma). Due to degeneracy of parameters no one individual experiment restricts eta. The bound appears as an interplay of the SNO and Gallium as well as SuperKamiokande data. Future measurements …
Sterile neutrinos may be an important extension to the standard model, and could both hold the key to understanding neutrino mass and mixing as well as play an important role in leptogenesis. In many models, the sterile neutrinos could be light and accessible to current and near term experiments. The MiniBooNE experiment is set up to explore these possibilities in the $Δm^{2}$ region from 0.3 to a few eV$^{2}$ where the LSND experiment has reported a $\barν_{e}$ appearance signal. This report will outline some of these extensions, give the status and prospects for the MiniBooNE experiment, and…
The IceCube Neutrino Observatory is capable of performing a unique search for sterile neutrinos through the exploitation of a matter enhanced resonant neutrino oscillation phenomena. As atmospheric muon neutrinos pass the dense material within the Earth, neutral current elastic forward scattering is predicted to induce a transition into a sterile state. This thesis presents two 3+1 sterile neutrino analyses by searching for spectral differences in the reconstructed energy and zenith direction of muon neutrino events, indicative of a transition into a sterile state. The first search probes the …
The IceCube neutrino telescope at the South Pole has measured the atmospheric muon neutrino spectrum as a function of zenith angle and energy in the approximate 320 GeV to 20 TeV range, to search for the oscillation signatures of light sterile neutrinos. No evidence for anomalous $ν_μ$ or $\barν_μ$ disappearance is observed in either of two independently developed analyses, each using one year of atmospheric neutrino data. New exclusion limits are placed on the parameter space of the 3+1 model, in which muon antineutrinos would experience a strong MSW-resonant oscillation. The exclusion limits…
We show that study of the atmospheric neutrinos in the 10--100 GeV energy range by DeepCore sub-array of the IceCube Neutrino Observatory can substantially constrain the mixing of sterile neutrinos of mass $\sim 1$ eV with active neutrinos. In the scheme with one sterile neutrino we calculate $ν_μ-$ and $\barν_μ-$ oscillation probabilities as well as zenith angle distributions of $ν_μ^{CC}$ events in different energy intervals in DeepCore. The distributions depend on the mass hierarchy of active neutrinos. Therefore, in principle, the hierarchy can be identified, if $ν_s$ exists. After a few y…
We analyze the energy and zenith angle distributions of the latest 2-year IceCube dataset of upward going atmospheric neutrinos to constrain sterile neutrinos at the eV scale in the 3+1 scenario. We find that the parameters favored by a combination of LSND and MiniBooNE data are excluded at more than the 99% C.L. We explore the impact of nonstandard matter interactions on this exclusion, and find that the exclusion holds for nonstandard interactions (NSI) that are within the stringent model-dependent bounds set by collider and neutrino scattering experiments. However, for large NSI parameters …
We report on results obtained at the Tevatron by the CDF and D0 collaborations up to June 2008 (2.4 fb-1), on searches for standard model (SM) Higgs bosons having a high mass (135-200 GeV). High mass Higgs bosons decay dominantly in WW and the presented searches are performed in the leptonic decay modes of the W's. Both direct production (ppbar -> H) and associated production (ppbar -> WH) are studied and eventually combined with all channels available at the Tevatron. Prospects for SM Higgs searches with the full projected Tevatron statistics are also given.
We provide a consistent framework to set limits on properties of light sterile neutrinos coupled to all three active neutrinos using a combination of the latest cosmological data and terrestrial measurements from oscillations, $β$-decay and neutrinoless double-$β$ decay ($0νββ$) experiments. We directly constrain the full $3+1$ active-sterile mixing matrix elements $|U_{\alpha4}|^2$, with $α\in ( e,μ,τ)$, and the mass-squared splitting $Δm^2_{41} \equiv m_4^2-m_1^2$. We find that results for a $3+1$ case differ from previously studied $1+1$ scenarios where the sterile is only coupled to one of…
The first description of the experimental program "OKA" with RF-separated K+/- beam at Protvino U-70 PS is presented. The parameters of the beam as well as the potential for CP-violation searches are discussed.
A sterile neutrino is a well motivated minimal new physics model that leaves an imprint in neutrino oscillations. Over the last two decades, a number of hints pointing to a sterile neutrino have emerged, many of which are pointing near $m_4\sim1$ eV. Here we show how MicroBooNE data can be used to search for electron neutrino disappearance using each of their four analysis channels. We find a hint for oscillations with the highest single channel significance of $2.4σ$ (using the Feldman-Cousins approach) coming from the Wire-Cell analysis and a simplified treatment of the experimental systemat…
Here we present the latest results of the charged Lepton Flavor Violation process searches at the BESIII experiment in the decay of $J/ψ$ to $eμ$, using $(225.3\pm2.8)\times10^6$ $J/ψ$ events collected with the BESIII detector at the BEPCII collider. An upper limit on the branching fraction of $B(J/ψ\rightarrow eμ)<1.6\times10^{-7}$ (90$\%$ C.L.) is obtained. The prospects and challenges with the future data are also discussed based on MC simulation.
The two long-baseline experiments ICARUS and OPERA have recently provided bounds on light ($\sim$ eV) sterile neutrinos exploiting the negative results of the $ν_μ\to ν_e$ appearance searches. Both collaborations have performed the data analysis using an effective 2-flavor description. We show that such a simplified treatment neglects sizable genuine 4-flavor effects, which are induced by the interference of the new large squared-mass splitting $Δm^2 _{14}$ with the atmospheric one. The inclusion in the data analysis of such effects weakens the upper bounds on the effective appearance amplitud…
MINOS is a two-detector on-axis experiment based at Fermilab. The NuMI neutrino beam encounters the MINOS Near Detector 1 km downstream before travelling 734 km through the Earth's crust, to reach the Far Detector located at the Soudan Underground Laboratory in Northern Minnesota. By searching for oscillations driven by a large mass splitting, MINOS is sensitive to the existence of sterile neutrinos. This poster will present results of a search for sterile neutrinos that is sensitive to the parameter space suggested by LSND and MiniBooNE. Both charged current numu and neutral current neutrino …
Current results of the MiniBooNE experiment show excess events that indicate neutrino oscillations, but only if one goes beyond the standard 3 family scenario. Recently a different explanation of the events has been given, not in terms of oscillations but by the production and decay of a massive sterile neutrino with large transition magnetic moment. We study the effect of such a sterile neutrino in the rare decays $τ^- \rightarrow μ^- μ^+ π^- ν$ and $τ^{-}\rightarrow μ^{-} μ^{+} e^{-} νν$. We find that searches for these decays featuring displaced vertices between the $μ^-$ and the other char…
This document presents the latest results for a 3+1 sterile neutrino search using the $10.56 \times 10^{20}$ protons-on-target data set taken from 2005 - 2012. By searching for oscillations driven by a large mass splitting, MINOS is sensitive to the existence of sterile neutrinos through any energy dependent deviations using a charged current sample, as well as looking at any relative deficit between neutral current events between the far and near detectors. This document will discuss the novel analysis that enabled a search for sterile neutrinos setting a limit in the previously unexplored re…
We discuss how the CMS and ATLAS experiments are preparing for the analysis of first LHC data with emphasis on the search for supersymmetry. We will show the importance of the understanding of detector, trigger, reconstruction and backgrounds, and we will present realistic estimates of the reach of CMS and ATLAS.
The PROSPECT experiment has substantially addressed the original 'Reactor Antineutrino Anomaly' by performing a high-resolution spectrum measurement from an enriched compact reactor core and a reactor model-independent sterile neutrino oscillation search based on the unique spectral distortions the existence of eV$^2$-scale sterile neutrinos would impart. But as the field has evolved, the current short-baseline (SBL) landscape supports many complex phenomenological interpretations, establishing a need for complementary experimental approaches to resolve the situation. While the global suite of…
The investigation of the electroweak symmetry breaking is one of the primary tasks of the experiments at the CERN Large Hadron Collider (LHC). The potential of the ATLAS experiment for the discovery of the Higgs boson(s) in Standard Model and Minimal Supersymmetric Standard Model is presented, with emphasis on studies which have been completed recently.
Searches for signatures of new physics in top anti-top events at the LHC require efficient reconstruction of top quarks with a broad range of transverse momenta. Three new reconstruction schemes are developed to deal with the large variety of top decay topologies. Their performance on the lepton + jets final state is evaluated using a detailed simulation of signal and background processes. Compared to previous ATLAS studies, a much improved reconstruction efficiency is found over a large top anti-top invariant mass range. As a consequence, even in the earliest phase of the experiment, ATLAS is…
The status of the search at LEP2 for the Higgs in the Standard Model (SM) and in the minimal supersymmetric extension of the Standard Model MSSM) is reviewed. A preliminary lower limit of 95.5/c^2 at 95% C.L. on the SM Higgs is obtained after a preliminary analysis of the data collected at sqrt(s)= 189 GeV. For standard choices of MSSM parameter sets, the search for the neutral Higgs bosons h and A leads to preliminary 95% C.L. exclusion lower limits of 83.5GeV/c^2 and 84.5 GeV/c^2, respectively.
The majority of neutrino oscillation experiments have obtained evidence for neutrino oscillations that are compatible with the three-flavor model. Explaining anomalous results from short-baseline experiments, such as LSND and MiniBooNE, in terms of neutrino oscillations requires the existence of sterile neutrinos. The search for sterile neutrino mixing conducted in NOvA uses a long baseline of 810 km between Near Detector (ND) at Fermilab and Far Detector (FD) in Minnesota. The signal for sterile neutrino oscillations is a deficit of neutral-current neutrino interactions at the FD with respect…
This note presents the prospects of searches for new heavy resonances decaying to diboson (WW) and measurements of electroweak WW/WZ production via vector boson scattering (VBS) in association with a high-mass dijet system in the $\ellνqq$ final states ($W\to\ellν$, $W/Z\to qq$). The prospects are presented for an integrated luminosity of 15 ab$^{-1}$ of proton-proton ($pp$) collisions at $\sqrt{s}=27$ TeV with an ATLAS-like detector simulated in the Delphes framework. The cross-section measurement of the electroweak $WW/WZ$ production in VBS processes is expected to reach the precision of $\s…
O(1) eV sterile neutrino can be responsible for a number of anomalous results of neutrino oscillation experiments. This hypothesis may be tested at short base-line neutrino oscillation experiments, several of which are either ongoing or under construction. Here we concentrate on the so-called Gallium anomaly, found by SAGE and GALLEX experiments, and its foreseeable future tests with BEST experiment at Baksan Neutrino Observatory. We start with a revision of the neutrino-gallium cross section, that is performed by utilizing the recent measurements of the nuclear final state spectra. We accordi…
The report describes the research program on the development of ultra-low-energy germanium detectors, with emphasis on WIMP dark matter searches. A threshold of 100 eV is achieved with a 20 g detector array, providing a unique probe to the low-mas WIMP. Present data at a surface laboratory is expected to give rise to comparable sensitivities with the existing limits at the $\rm{5 - 10 GeV}$ WIMP-mass range. The projected parameter space to be probed with a full-scale, kilogram mass-range experiment is presented. Such a detector would also allow the studies of neutrino-nucleus coherent scatteri…
Searches for this Higgs boson are reaching an exciting time. This proceeding reports the progress on Standard Model Higgs boson searches at the Tevatron and the prospects for Higgs boson searches at the Large Hadron Collider. Also reported are the results of non Standard Model searches and prospects at the Tevatron, Large Hadron Collide and B factories. Included in this result are the first limits on the mass of the Standard Model Higgs boson at high masses beyond the kinematic reach of the Large Electron Positron collider.
Several anomalies observed in short-baseline neutrino experiments indicate that the standard 3-flavor framework may be incomplete and point towards the existence of light sterile neutrinos. Here, we present a concise review of the status of the neutrino oscillations within the 3+1 scheme, which is a minimal extension of the standard 3-flavor framework with one sterile neutrino species. We emphasize the potential role of LBL experiments in the searches of CP violation connected to sterile neutrinos and their complementarity with the SBL experiments.
We use the LHC Higgs data to derive updated constraints on electroweak-scale sterile neutrinos that naturally occur in many low-scale seesaw extensions of the Standard Model to explain the neutrino masses. We also analyze the signal sensitivity for a new final state involving a single charged lepton and two jets with missing energy, which arises from the decay of sterile neutrinos produced through the Higgs and $W,Z$ boson mediated processes at the LHC. Future prospects of these sterile neutrino signals in precision Higgs measurements, as well as at a future 100 TeV collider, are also discusse…
A considerable experimental effort is currently under way to test the persistent hints for oscillations due to an eV-scale sterile neutrino in the data of various reactor neutrino experiments. The assessment of the statistical significance of these hints is usually based on Wilks' theorem, whereby the assumption is made that the log-likelihood is $χ^2$-distributed. However, it is well known that the preconditions for the validity of Wilks' theorem are not fulfilled for neutrino oscillation experiments. In this work we derive a simple asymptotic form of the actual distribution of the log-likeli…
This paper reviews the results of the LSND and MiniBooNE experiments. The primary goal of each experiment was to effect sensitive searches for neutrino oscillations in the mass region with $Δm^2 \sim 1$ eV$^2$. The two experiments are complementary, and so the comparison of results can bring additional information with respect to models with sterile neutrinos. Both experiments obtained evidence for $\bar ν_μ\rightarrow \bar ν_e$ oscillations, and MiniBooNE also observed a $ν_μ\rightarrow ν_e$ excess. In this paper, we review the design, analysis, and results from these experiments. We then con…
We propose new searches that exploit the unique signatures of decaying sterile neutrinos with masses below $M_W$ at the LHC, where they can be produced in rare decays of Standard Model gauge bosons. We show that for few-GeV-scale sterile neutrinos, the LHC experiments can probe mixing angles at the level of $10^{-4}-10^{-3}$ through powerful searches that look for prompt leptons in association with displaced lepton jets. For higher-mass sterile neutrinos, ${\it i.e.}$, $M_N \gtrsim 15$ GeV, Run II can explore similarly small mixing angles in prompt multilepton final states. This represents an …
Solar neutrino experiments are highly sensitive to sources of $ν\to\overlineν$ conversions in the $^8$B neutrino flux. In this work we adapt these searches to non-minimal sterile neutrino models recently proposed to explain the LSND, MiniBooNE, and reactor anomalies. The production of such sterile neutrinos in the Sun, followed the decay chain $ν_4 \to νϕ\to νν\overlineν$ with a new scalar $ϕ$ results in upper limits for the neutrino mixing $|U_{e4}|^2$ at the per mille level. We conclude that a simultaneous explanations of all anomalies is in tension with KamLAND, Super-Kamiokande, and Borexi…
The OPERA experiment at the CNGS beam has observed muon to tau neutrino oscillations in the atmospheric sector. Based on this result new limits on the mixing parameters of a massive sterile neutrino may be set. Preliminary results of the analysis done in the 3+1 neutrino framework are here presented. An update of the search for sterile neutrinos in the $ν_μ \rightarrow ν_e$ channel is also given. The status of the searches for sterile neutrinos performed at other Long--Baseline experiments (MINOS at NuMI beam and SuperK with the atmospheric flux) is also briefly recalled. Finally, some persona…
This paper is written as one chapter in a collection of essays on neutrino physics for beginning graduate students. The text presents important experimental methods and issues for those interested in searches for sterile neutrinos. Other essays in the collection, written by other authors, will cover introduction to neutrinos in the Standard Model, a description of the theory, and discussion of details of detectors, thus these aspects are not covered here. However, beyond these points, this represents a self-contained tutorial on experimental studies of sterile neutrino oscillations, covering s…
