We have studied the mass hierarchy with atmospheric neutrinos considering the muon energy and zenith angle of the event at the magnetized iron calorimeter detector. For $χ^2$ analysis we have migrated the number of events from neutrino energy and zenith angle bins to muon energy and zenith angle bins using the two-dimensional energy-angle correlated resolution functions. The binning of data is made in two-dimensional grids of $\log_{10} E - L^{0.4}$ plane to get a better reflection of the oscillation pattern in the $χ^2$ analysis. Then the $χ^2$ is marginalized considering all possible systematic uncertainties of the atmospheric neutrino flux and cross section. The effects of the ranges of oscillation parameters on the marginalization are also studied. The lower limit of the range of $θ_{13}$ for marginalization is found to be very crucial in determining the sensitivity of hierarchy for a given $θ_{13}$. Finally, we show that one can discriminate atmospheric neutrino mass hierarchy at $>$90% C.L. if the lower limit of $θ_{13} \ge 5^\circ$.
The muon tagging is an essential tool to distinguish between gamma and hadron-induced showers in wide field-of-view gamma-ray observatories. In this work, it is shown that an efficient muon tagging (and counting) can be achieved using a water Cherenkov detector with a reduced water volume and 4 PMTs, provided that the PMT signal spatial and time patterns are interpreted by an analysis based on Machine Learning (ML). The developed analysis has been tested for different shower and array configurations. The output of the ML analysis, the probability of having a muon in the WCD station, has been u…
We study the sensitivity of the Iron Calorimeter (ICAL) at the India-Based Neutrino Observatory (INO) to Lorentz and CPT violation in the neutrino sector. Its ability to identify the charge of muons in addition to their direction and energy makes ICAL a useful tool in putting constraints on these fundamental symmetries. Using resolution, efficiencies, errors and uncertainties obtained from ICAL detector simulations, we determine sensitivities to $δ{b}_{31}$, which parametizes the violations in the muon neutrino sector. We carry out calculations for three generic cases representing mixing in th…
Neutrinos from STORed Muons (nuSTORM; formerly VLENF) is a proposed experiment to use 3.8 GeV/c muon decay to produce a well-understood beam of electron and muon neutrinos that can be used for short baseline physics. A magnetized far detector allows for the wrong-sign muon appearance physics of electron-neutrino to muon-neutrino. This channel is the CPT of the LSND anomaly and provides 10 sigma sensitivity to the anomaly. This note contains a detailed explanation of the nSTORM appearance analysis that was included in the Letter of Intent.
In order to fully address the oscillation processes at a neutrino factory, a detector should be capable of identifying and measuring all three charged lepton flavors produced in charged current interactions {\it and} of measuring their charges to discriminate the incoming neutrino helicity. This is an experimentally challenging task, given the required detector mass for long-baseline experiments. We address the benefit of a high-granularity, excellent-calorimetry non-magnetized target-detector, which provides a background-free identification of electron neutrino charged current and a kinematic…
Wide field-of-view gamma-ray observatories must fight the overwhelming cosmic ray background to identify very-high-energy astrophysical gamma-ray events. This work introduces a novel gamma/hadron discriminating variable, $LCm$, which quantifies the azimuthal non-uniformity of the particle distributions at the ground. This non-uniformity, due to the presence of hadronic sub-showers, is higher in proton-induced showers than in gamma showers. The discrimination power of this new variable is then discussed, as a function of the air shower array fill factor, in the energy range $10\,$TeV to $1\,$Pe…
We investigate the expected neutrino emissivity from nuclear collisions in magnetically dominated collisional models of gamma-ray bursts, motivated by recent observational and theoretical developments. The results indicate that significant multi-GeV neutrino fluxes are expected for model parameter values which are typical of electromagnetically detected bursts. We show that for detecting at least one muon event in Icecube and its Deep Core sub-array, a single burst must be near the high end of the luminosity function and at a redshift $z\lesssim 0.2$. We also calculate the luminosity and dista…
We propose a new experiment to search for a time-reversal (T) symmetry breaking process in muon decay and the Majoranality of the neutrinos. In the presence of V+A interactions, the Majoranality appears as a T-violating term in the muon decay width as shown by Doi et al, while in the Standard Model such a T-violating term is negligibly small. The presences of V+A interactions and the corresponding heavy right-handed Majorana neutrinos give us an important clue to solve two major issues in particle physics, the deficit of baryon asymmetry in the universe and the Majoranality of neutrinos. In th…
We calculate the intensities and angular distributions of positive and negative muons produced by atmospheric neutrinos. We comment on some sources of uncertainty in the charge ratio. We also draw attention to a potentially interesting signature of neutrino oscillations in the muon charge ratio, and we discuss the prospects for its observation (which are not quite within the reach of currently planned magnetized detectors).
The India-based Neutrino Observatory (INO) will host a 50 kt magnetized iron calorimeter (ICAL) detector that will be able to detect muon tracks and hadron showers produced by Charged-Current muon neutrino interactions in the detector. The ICAL experiment will be able to determine the precision of atmospheric neutrino mixing parameters and neutrino mass hierarchy using atmospheric muon neutrinos through earth matter effect. In this paper, we report on the sensitivity for the atmospheric neutrino mixing parameters ($\sin^{2}θ_{23}$ and $|Δm^{2}_{32}|$) for the ICAL detector using the reconstruc…
High density magnetized detectors are well suited to exploit the outstanding purity and intensities of novel neutrino sources like Neutrino Factories and Beta Beams. They can also provide independent measurements of leptonic mixing parameters through the observation of atmospheric muon-neutrinos. In this paper, we discuss the combination of these observables from a multi-kton iron detector and a high energy Beta Beam; in particular, we demonstrate that even with moderate detector granularities the neutrino mass hierarchy can be determined for $θ_{13}$ values greater than 4$^\circ$.
The proposed Iron Calorimeter (ICAL) detector at Indian Neutrino Observatory(INO) will be a large (50 kt) magnetized detector located 1270 m underground at Bodi West Hills in Tamilnadu. ICAL is capable of identifying the charge of the particles. In this paper its potential for the measurement of the muon charge ratio is explored by means of a detailed simulation-based study, first using the CORSIKA code and then comparing it with an analytical model (the "pika" model). The estimated muon charge ratio is in agreement with the existing experimental observations, its measure can be extended by IN…
Time-Structured Tail Probabilities for Ultra-High-Energy Gamma-Hadron Discrimination in Water-Cherenkov Arrays
Universidade de Lisboa（里斯本大学）；Instituto Superior Técnico (IST)（高等技术研究所）；Laboratório de Instrumentação e Física Experimental de Partículas (LIP)（粒子实验物理与仪器实验室）
The accurate prediction of the neutrino beam produced in muon decays and the absence of opposite helicity contamination for a particular neutrino flavor make a future neutrino factory the ideal place to look for the lepton flavor violating (LFV) decays of the kind $μ^+\ra e^+\nuebar\numu$ and lepton number violating (LNV) processes like $μ^-\ra e^-\nue\numu$. Excellent sensitivities can be achieved using a detector capable of muon and/or electron identification with charge discrimination. This would allow to set experimental limits that improve current ones by more than two orders of magnitude…
Operator Identification in Charged Lepton-Flavor Violation: Global EFT Analysis with RG Evolution, Polarization Observables, and Bayesian Model Discrimination at Future Colliders
Universidad Técnica Federico Santa María（弗雷德里克·萨马利亚技术大学）；Millennium Institute for Subatomic Physics at the High-Energy Frontier (SAPHIR)（高能前沿亚原子物理千年研究所（SAPHIR））
Neutrino Tridents and $W$-boson production at the Muon Collider
Universität Bonn（波恩大学）；National Centre for Nuclear Research（国家核研究中心）；Nicolaus Copernicus Astronomical Center Polish Academy of Sciences（波兰科学院尼古拉·哥白尼天文学中心）；The Pennsylvania State University（宾夕法尼亚州立大学）；Fermi National Accelerator Laboratory（费米国家加速器实验室）；University of Chicago（芝加哥大学）
The proposed ICAL detector at INO is a large sized underground magnetized iron detector. ICAL is designed to reconstruct muon momentum using magnetic spectrometers. Energy measurement using magnets fail for muons in TeV range, since the angular deflection of the muon in the magnetic field is negligible and the muon tracks become nearly straight. A new technique for measuring the energy of muons in the TeV range is used by the CCFR neutrino detector, known as the Pair-Meter technique. This technique estimates muon energy from measurements of the energy deposited by the muon in many layers of an…
High-quality charged current quasielastic scattering data have recently been reported for both muon neutrinos and antineutrinos from several accelerator-based neutrino experiments. Measurements from MiniBooNE were the first to indicate that more complex nuclear effects, now thought to be the result of nucleon pair correlations, may contribute to neutrino quasielastic samples at a much higher significance than previously assumed. These findings are now being tested by MINER$ν$A and other contemporary neutrino experiments. Presented here is a comparison of data from MiniBooNE and MINER$ν$A to a …
We investigate the potential of the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) to discriminate between two theoretical models predicting anomalous events with jets and large missing transverse energy, minimal supersymmetry and Little Higgs with T Parity. We focus on a simple test case scenario, in which the only exotic particles produced at the LHC are heavy color-triplet states (squarks or T-quarks), and the only open decay channel for these particles is into the stable missing-energy particle (neutralino or heavy photon) plus a quark. We find that in this scenari…
We study the discovery potential of the non-Standard Model (SM) heavy Higgs bosons in the Two-Higgs-Doublet Models (2HDMs) at a multi-TeV muon collider and explore the discrimination power among different types of 2HDMs. We find that the pair production of the non-SM Higgs bosons via the universal gauge interactions is the dominant mechanism once above the kinematic threshold. Single Higgs boson production associated with a pair of heavy fermions could be important in the parameter region with enhanced Yukawa couplings. For both signal final states, $μ^+μ^-$ annihilation channels dominate over…
The pattern of oscillation parameters emerging from current experimental data can be further elucidated by the observation of matter effects. In contrast to planned experiments with conventional neutrino beams, atmospheric neutrinos offer the possibility to search for Earth-induced matter effects with very long baselines. Resonant matter effects are asymmetric on neutrinos and anti-neutrinos, depending on the sign of $Δm^2$. In a three-generation oscillation scenario, this gives access to the mass hierarchy of neutrinos, while the size of the asymmetry would measure the admixture of electron n…
We calculate the yield of high energy neutrinos produced in astrophysical sources with negligible magnetic fields varying their interaction depth from nearly transparent to opaque. We take into account the scattering of secondaries on background photons as well as the direct production of neutrinos in decays of charm mesons. If multiple scattering of nucleons becomes important, the neutrino spectra from meson and muon decays are strongly modified with respect to transparent sources. Characteristic for neutrino sources containing photons as scattering targets is a strong energy-dependence of th…
Neutrino mass hierarchy can be measured in atmospheric neutrino experiments through the observation of earth matter effects. Magnetized iron calorimeters have been shown to be good in this regard due to their charge identification capabilities. The charged current interaction of $ν_μ$ in this detector, produces a muon track and a hadron shower. The direction of the muon track can be measured very accurately. We show the improvement expected in the reach of this class of experiments to the neutrino mass hierarchy, as we improve the muon energy resolution and the muon reconstruction efficiency. …
Muon Bremsstrahlung as a New Probe of Dark Sector at Neutrino Experiments
Washington University（华盛顿大学）；Johannes Gutenberg-Universität Mainz（美因茨约翰内斯古腾堡大学）；Texas A&M University（德克萨斯农工大学）；University of Michigan（密歇根大学）；University of Pittsburgh（匹兹堡大学）
We show that a very precise neutrino/anti-neutrino event separation is not mandatory to cover the physics program of a low energy neutrino factory and thus non-magnetized detectors like water Cerenkov or liquid Argon detectors can be used. We point out, that oscillation itself strongly enhances the signal to noise ratio of a wrong sign muon search, provided there is sufficiently accurate neutrino energy reconstruction. Further, we argue that apart from a magnetic field, other means to distinguish neutrino from anti-neutrino events (at least statistically) can be explored. Combined with the fac…
Earth medium effects in the three-neutrino oscillations of atmospheric neutrinos are observable under appropriate conditions. This paper generalizes the study of the medium effects and the possibility of their observation in the atmospheric neutrino oscillations from the case of neutrinos traversing only the Earth mantle, where the density is essentially constant, to the case of atmospheric neutrinos crossing also the Earth core. In the latter case new resonance-like effects become apparent. We calculate the CPT-odd asymmetry for the survival probability of muon neutrinos and the observable mu…
Scintillation light is used in liquid argon (LAr) neutrino detectors to provide a trigger signal, veto information against cosmic rays, and absolute event timing. In this work, we discuss additional opportunities offered by detectors with enhanced sensitivity to scintillation light, that is with light collection efficiencies of about $10^{-3}$. We focus on two key detector performance indicators for neutrino oscillation physics: calorimetric neutrino energy reconstruction and neutrino/antineutrino separation in a non-magnetized detector. Our results are based on detailed simulations, with neut…
Motivated by recent hints of large θ13 from the T2K, MINOS and Double Chooz experiments, we study the physics reach of a Low Energy Neutrino Factory (LENF) and its dependence on the chosen baseline distance, L, and stored-muon energy, E_μ, in order to ascertain the configuration of the optimal LENF. In particular, we study the performance of the LENF over a range of baseline distances from 1000 km to 4000 km and stored-muon energies from 4 GeV to 25 GeV, connecting the early studies of the LENF (1300 km, 4.5 GeV) to those of the conventional, high-energy neutrino factory design (4000 km and 70…
We have analyzed the atmospheric neutrino data to study the octant of $θ_{23}$ and the precision of the oscillation parameters for a large Iron CALorimeter (ICAL) detector. The ICAL being a tracking detector has the ability to measure the energy and the direction of the muon with high resolution. From bending of the track in magnetic field it can also distinguish its charge. We have generated events by Nuance and then considered only the muons (directly measurable quantities) produced in charge current interactions in our analysis. This encounters the main problem of wide resolutions of energy…
Among the combinations $L_e-L_μ$, $L_e-L_τ$ and $L_μ-L_τ$ any one can be gauged in anomaly free way with the standard model gauge group. The masses of these gauge bosons can be so light that it can induce long-range forces on the Earth due to the electrons in the Sun. This type of forces can be constrained significantly from neutrino oscillation. As the sign of the potential is opposite for neutrinos and antineutrinos, a magnetized iron calorimeter detector (ICAL) would be able to produce strong constraint on it. We have made conservative studies of these long-range forces with atmospheric neu…
We investigate the minimal performance, in terms of beam luminosity and detector size, of a neutrino factory to achieve a competitive physics reach for the determination of the mass hierarchy and the discovery of leptonic CP violation. We find that a low luminosity of $2\times 10^{20}$ useful muon decays per year and 5 GeV muon energy aimed at a 10 kton magnetized liquid argon detector placed at 1300 km from the source provides a good starting point. This result relies on $θ_{13}$ being large and assumes that the so-called platinum channel can be used effectively. We find that such a minimal f…
We study the neutrino mass hierarchy at the magnetized Iron CALorimeter (ICAL) detector at India-based Neutrino Observatory with atmospheric neutrino events generated by the Monte Carlo event generator Nuance. We judicially choose the observables so that the possible systematic uncertainties can be reduced. The resolution as a function of both energy and zenith angle simultaneously is obtained for neutrinos and anti-neutrinos separately from thousand years un-oscillated atmospheric neutrino events at ICAL to migrate number of events from neutrino energy and zenith angle bins to muon energy and…
We consider the prospects for a neutrino factory to measure mixing angles, the CP violating phase and mass-squared differences by detecting wrong-charged muons arising from the chain μ^+ to ν_e to ν_μ to μ^- and the right-charged muons coming from the chain μ^+ to \barν_μ to \barν_μ to μ^+ (similar to μ^- chains), where ν_e to ν_μ and \barν_μ to \barν_μ are neutrino oscillation channels through a long baseline. First, we perform the baseline and energy optimization of the neutrino factory including the latest simulation results from the magnetized iron neutrino detector (MIND). Second, we stud…
The neutral current non-standard interactions (NSI's) of neutrino with matter fermions while propagating through long distances inside the Earth matter can give rise to the extra matter potentials apart from the standard MSW potential due to the $W$-mediated interactions in matter. In this paper, we explore the impact of flavor violating neutral current NSI parameter $\varepsilon_{μτ}$ in the oscillation of atmospheric neutrino and antineutrino using the 50 kt magnetized ICAL detector at INO. We find that due to non-zero $\varepsilon_{μτ}$, $ν_μ\rightarrowν_μ$ and $\barν_μ\rightarrow\barν_μ$ t…
The neutrino self-energy is calculated in a weakly magnetized plasma consists of electrons, protons, neutrons and their anti-particles and using this we have calculated the neutrino effective potential up to order $M^{-4}_W$. In the absence of magnetic field it reduces to the known result. We have also calculated explicitly the effective potentials for different backgrounds which may be helpful in different environments. By considering the mixing of three active neutrinos in the medium with the magnetic field we have derived the survival and conversion probabilities of neutrinos from one flavo…
One of the unknown parameters in neutrino oscillations is the octant of the mixing angle theta_{23}. In this paper, we discuss the possibility of determining the octant of theta_{23} in the long baseline experiments T2K and NOvA in conjunction with future atmospheric neutrino detectors, in light of non-zero value of theta_{13} measured by reactor experiments. We consider two detector technologies for atmospheric neutrinos - magnetized iron calorimeter and non-magnetized Liquid Argon Time Projection Chamber. We present the octant sensitivity for T2K/NOvA and atmospheric neutrino experiments sep…
Atmospheric neutrinos travel very long distances through earth matter. It is expected that the matter effects lead to significant changes in the neutrino survival and oscillation probabilities. Initial analysis of atmospheric neutrino data by the Super- Kamiokande collaboration is done using the vacuum oscillation hypothesis, which provided a good fit to the data. In this work, we did a study to differentiate the effects of vacuum oscillations and matter modified oscillations in the atmospheric neutrino data. We find that magnetized iron detector, ICAL at INO, can make a 3 sigma discrimination…
We have studied $CPT$ violation in neutrino oscillation considering three flavor framework with matter effect. We have constructed a new way to find the oscillation probability incorporating $CPT$ violating terms without any approximation. Then $CPT$ violation with atmospheric neutrinos for a magnetized iron calorimeter detector considering the muons (directly measurable with high resolution) of the charge current events has been studied for zero and nonzero $θ_{13}$ values. It is found that a potential bound of $δb_{32} \lapp 6\times 10^{-24}$ GeV at 99% CL can be obtained with 1 Mton.year ex…
The error probability of the discrimination of the Standard Model (SM) with massive neutrinos and its new physics (NP) model extension in experiments of the muon neutrino oscillation, following the pion decay $π^{+} \rightarrow μ^{+} + ν_μ$, is calculated. The stability of the estimation of the NP charged current coupling constant $\varepsilon_{R}$ is analysed and the robustness of this estimation is checked. It is shown that the upper bound on the error probability of erroneous identification of the Standard Model with its NP model extension has reached the significantly small value of approx…
We present a Neutrino-Factory-based setup with three detectors of different kind in principle capable to solve the eightfold-degeneracy in the simultaneous measurement of $θ_{13}$ and $δ$, for $θ_{13} \geq 1^\circ (\sin^2 (2 θ_{13}) \geq 10^{-3})$. Our setup includes a Superbeam-driven water Cherenkov (the Superbeam conceived as the first stage of the Neutrino Factory); two muon-storage-ring-driven detectors (namely, a large magnetized iron calorimeter and an emulsion cloud chamber) to take advantage of both the so-called "golden" ($ν_e \to ν_μ$) and "silver" ($ν_e \to ν_τ$) channels.
We discuss the reconstruction of neutrino flavor neutrino at a distant source in the very high en- ergy regime. This reconstruction procedure is relevant to the confirmation of detecting cosmogenic neutrinos, for example. To facilitate such a reconstruction, it is imperative to achieve effective flavor discriminations in terrestrial neutrino telescopes. We note that, for energies beyond few tens of PeV, a tau-lepton behaves like a track similar to a muon. Hence, while it is rather challenging to separate νμ from ντ in this case, one can expect to isolate νe from the rest by a distinctive showe…
We have studied the prospects of measuring the CP violating phase with atmospheric neutrinos at a large magnetized iron calorimeter detector considering the muons (directly measurable) of the neutrino events generated by a MonteCarlo event generator Nuance. The effect of $θ_{13}$ and $δ_{CP}$ appears dominantly neither in atmospheric neutrino oscillation nor in solar neutrino oscillation, but appears as subleading in both cases. These are observable in range of $E \sim 1$ GeV for atmospheric neutrino, where solar and atmospheric oscillation couple. In this regime, the quasi-elastic events domi…
MONOLITH is a proposed massive magnetized tracking calorimeter at the Gran Sasso laboratory in Italy, optimized for the detection of atmospheric muon neutrinos. The main goal is to test the neutrino oscillation hypothesis through an explicit observation of the full first oscillation swing. The sensitivity range for this measurement comfortably covers the entire Super-Kamiokande allowed region. Other measurements include studies of matter effects, the NC/CC and neutrino/anti-neutrino ratio with atmospheric neutrinos and auxiliary measurements from the CERN to Gran Sasso neutrino beam. Depending…
The down-going atmospheric ν_μ and {\bar{ν_μ}} fluxes can be significantly altered due to the presence of eV^2-scale active-sterile oscillations. We study the sensitivity of a large Liquid Argon detector and a large magnetized iron detector (like the proposed ICAL at INO) to these oscillations. Such oscillations are indicated by results from LSND, and more recently, from MiniBooNE and from reanalyses of reactor experiments following recent recalculations of reactor fluxes. There are other tentative indications of the presence of sterile states in both the νand {\barν} sectors as well. Using th…
The leptonic CP-violating phase $δ$ can be measured with a Neutrino Factory with $2 \times 10^{20} $ useful muons per year, if the solar neutrino problem is solved by the LMA-MSW solution, with $Δm_{12}^2 \ge 2 \times 10^{-5}$ eV$^2$ (in this analysis a 40 kT magnetized iron detector is considered, taking into account its efficiencies and backgrounds). If LSND is confirmed, CP-violating phenomena in four-family scenarios can be most easily addressed with a small 1 kT detector at $L = \cal O$(10) km (no detailed analysis of the detector efficiencies and backgrounds has been performed in this ca…
On 2010 MINOS experiment was showing an hint of possible different mass splitting and mixing angles for neutrinos and anti-neutrinos, suggesting a charge-parity-time (CPT) violation in the lepton sector; last year 2012 a second result from MINOS showed a reduced discrepancy between the two set of parameters, nearly compatible with no CPT violation. We proposed an experiment for more precise estimation of neutrino oscillation parameters being useful not only for a complete discrimination for CPT scenarios, but also for mass hierarchy and theta 13 determination, and mostly for the first oscillat…
Use of low energy atmospheric neutrinos is considered for precision measurement of neutrino mixing parameters. At around energy $E \simeq$ a few $\times$100 MeV and baseline $L$ of a few $\times$1000 km, CP phase effect is $\sim$10 times larger than that of the conventional LBL accelerator neutrino experiments. We report here a few progresses: (1) To analyze physics in the region, a new perturbative framework at around the solar-scale enhancement is developed. (2) To know the characteristic features of CP $δ$ dependence of the atmospheric neutrinos at low energies, we plot the ratio of the $ν_…
In neutrino oscillation with non-standard interactions (NSI) the system is enriched with CP violation caused by phases due to NSI in addition to the standard lepton Kobayashi-Maskawa phase δ. In this paper we show that it is possible to disentangle the two CP violating effects by measurement of muon neutrino appearance by a near-far two detector setting in neutrino factory experiments. Prior to the quantitative analysis we investigate in detail the various features of the neutrino oscillations with NSI, but under the assumption that only one of the NSI elements, ε_{e μ} or ε_{e τ}, is present.…
A new experiment with an intense ~2 GeV neutrino beam at CERN SPS is proposed in order to definitely clarify the possible existence of additional neutrino states, as pointed out by neutrino calibration source experiments, reactor and accelerator experiments and measure the corresponding oscillation parameters. The experiment is based on two identical LAr-TPCs complemented by magnetized spectrometers detecting electron and muon neutrino events at Far and Near positions, 1600 m and 300 m from the proton target, respectively. The ICARUS T600 detector, the largest LAr-TPC ever built with a size of…
The concept of a small, single-layer water Cherenkov detector, with three photomultiplier tubes (PMTs), placed at its bottom in a $120^{\circ}$ star configuration (\emph{Mercedes} Water Cherenkov Detector) is presented. The PMTs are placed near the lateral walls of the stations with an adjustable inclination and may be installed inside or outside the water volume. To illustrate the technical viability of this concept and obtain a first-order estimation of its cost, an engineering design was elaborated. The sensitivity of these stations to low energy Extensive Air Shower (EAS) electrons, photon…
The study has been carried out on the prospects of probing the sterile neutrino mixing with the magnetized Iron CALorimeter (ICAL) at the India-based Neutrino Observatory (INO), using atmospheric neutrinos as a source. The so-called 3~$+$~1 scenario is considered for active-sterile neutrino mixing and lead to projected exclusion curves in the sterile neutrino mass and mixing angle plane. The analysis is performed using the neutrino event generator NUANCE, modified for ICAL, and folded with the detector resolutions obtained by the INO collaboration from a full GEANT4 based detector simulation. …
Pioneering atmospheric muon neutrino experiments have demonstrated the near-maximal magnitude of the flavor mixing angle $θ_{23}$. But the precise value of the deviation $D \equiv 1/2 - \sin^2 θ_{23}$ from maximality (if nonzero) needs to be known, being of great interest -- especially to builders of neutrino mass and mixing models. We quantitatively investigate in a three generation framework the feasibility of determining $D$ in a statistically significant manner from studies of the atmospheric $ν_μ,\barν_μ$ survival probability including both vacuum oscillations and matter effects. We show …
We point out that the measurement of the $L/E$ distribution of atmospheric neutrino events with sufficient resolution in order to observe the characteristic modulations of neutrino oscillations would provide a unique way to test the $\numunux$ oscillations nature of the atmospheric neutrino anomaly in the parameter range $5\times 10^{-4} < Δm^2 < 2\times 10^{-3}\rm\ eV^2$. With an integrated exposure of a few tens of kiloton-year, this method can cover the lower part of the $Δm^2$ region of the currently allowed atmospheric neutrino solution and is therefore complementary to the one explorable…
We study the potential of a Neutrino Factory in constraining the parameter space of a scheme with one sterile neutrino separated from three active ones by an O(1) eV^2, mass-squared difference. We present approximated analytic expressions for the oscillation probabilities, showing that the greatest sensitivity to sterile neutrinos at a Neutrino Factory can be achieved using the ν_μ->ν_μand the ν_μ->ν_τoscillations. We have studied two setups: a Neutrino Factory with 50 GeV (20 GeV) stored muons, with two detectors of the Hybrid-MIND type (a magnetized ECC next to a magnetized iron calorimeter)…
