We extend our calculation of the atmospheric neutrino fluxes to polar and tropical regions. It is well known that the air density profile in the polar and the tropical regions are different from the mid-latitude region. Also there are large seasonal variations in the polar region. In this extension, we use the NRLMSISE-00 global atmospheric model [1] replacing the US-standard '76 atmospheric model [2], which has no positional or seasonal variations. With the NRLMSISE-00 atmospheric model, we study the atmospheric neutrino flux at the polar and tropical regions with seasonal variations. The geomagnetic model IGRF [3] we have used in our calculations seems accurate enough in the polar regions also. However, the polar and the equatorial regions are the two extremes in the IGRF model, and the magnetic field configurations are largely different to each other. Note, the equatorial region is also the tropical region generally. We study the effect of the geomagnetic field on the atmospheric neutrino flux in these extreme regions.

Future high-precision neutrino interaction experiments are needed to extend the current program of GeV-scale neutrino interactions and should include:1. A feasibility study of a high-statistics hydrogen or deuterium scattering experiment to supplement the currently poorly known (anti)neutrino-nucleon cross sections.2. The need for (anti)neutrino Ar scattering data in the energy range relevant for the DUNE experiment.3. The possibility of muon-based neutrino beams providing extremely accurate knowledge of the neutrino flux and an intense electron neutrino beam.• Current and future long-and short-baseline neutrino oscillation programs should evaluate and articulate what additional neutrino-nucleus interaction data is required to meet their ambitious goals and support experiments that provide this data.In addition to these general challenges facing the community, there are more specific concerns for particular topics and interaction channels. These are summarized below in the form of observations, problem description or recommendations. For a deeper insight, the reader is encouraged to consult the subsequent sections of this paper.

The coherent pion production induced by neutrinos in nuclei is studied using a delta hole model in local density approximation taking into account the renormalization of ∆ properties in a nuclear medium. The pion absorption effects have been included in an eikonal approximation. These effects give a large reduction in the total cross section. The numerical results for the total cross section are found to be consistent with recent experimental results from K2K and MiniBooNE collaborations and other older experiments in the intermediate energy region.PACS numbers: 13.15.+g, 23.40.Bw, 25.30.Pt The present experiments at K2K and MiniBooNE are designed to search for ν-oscillations in ν µ disappearance and ν e appearance channels. In these experiments, the ν µ -spectrum is determined by the observed energy spectrum of muons which are predominantly produced in forward direction through the charged current quasielastic reactions induced by ν µ . In this kinematic region the major background to these events come from the non quasielastic events in which pions are produced through coherent and incoherent processes induced by charged and neutral weak currents in ν-nucleus interactions. The neutral current induced π 0 production is of particular importance as it constitutes a major background to the electron signal in ν e appearance channel. The analysis of ν-oscillation experiments, therefore, requires a better understanding of pion production processes in ν-nucleus interaction and many experiments are being done to study ν-induced coherent and incoherent production of pions from nuclei [1].The coherent production of charged pions from 12 C has been recently studied by the K2K collaboration [2]. The coherent production of neutral pions has been studied by the K2K collaboration for 16 O [3] and by the MiniBooNE collaboration for 12 C [4]. Many experimental groups have earlier studied the coherent production of pions induced by neutrinos from other nuclei at higher energies [5]- [7]. Theoretically various authors [8]-[9] have used Adler's PCAC theorem to predict the total cross sections for neutrino reactions, which overestimate the experimental cross sections at low energies. In these calculations the nuclear medium effects are included only through the final state interaction of the outgoing pions with the nucleus using a model of pion nucleus scattering. A theoretical framework for treating the nuclear medium effects in the neutrino production of coherent pions using some model of nuclear structure has been recently discussed by some groups [10] but no definite predictions are made for the kinematics of the neutrino oscillation experiments of present interest.We present in this letter a calculation of the neutrino induced production of coherent pions from nuclei at intermediate neutrino energies. The nuclear medium effects are taken into account in the weak production process as well as in the final state interaction of the outgoing pions with the nucleus. The calculation uses the local density approximation to the de...

The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO) is designed to study the atmospheric neutrinos and antineutrinos separately over a wide range of energies and path lengths. The primary focus of this experiment is to explore the Earth matter effects by observing the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range. This study will be crucial to address some of the outstanding issues in neutrino oscillation physics, including the fundamental issue of neutrino mass hierarchy. In this document, we present the physics potential of the detector as obtained from realistic detector simulations. We describe the simulation framework, the neutrino interactions in the detector, and the expected response of the detector to particles traversing it. The ICAL detector can determine the energy and direction of the muons to a high precision, and in addition, its sensitivity to multi-GeV hadrons increases its physics reach substantially. Its charge identification capability, and hence its ability to distinguish neutrinos from antineutrinos, makes it an efficient detector for determining the neutrino mass hierarchy. In this report, we outline the analyses carried out for the determination of neutrino mass hierarchy and precision measurements of atmospheric neutrino mixing parameters at ICAL, and give the expected physics reach of the detector with 10 years of runtime. We also explore the potential of ICAL for probing new physics scenarios like CPT violation and the presence of magnetic monopoles. v Physics Potential of ICAL at INO vi PrefaceThe past two decades in neutrino physics have been very eventful, and have established this field as one of the flourishing areas of high energy physics. Starting from the confirmation of neutrino oscillations that resolved the decades-old problems of the solar and atmospheric neutrinos, we have now been able to show that neutrinos have nonzero masses, and different flavors of neutrinos mix among themselves. Our understanding of neutrino properties has increased by leaps and bounds. Many experiments have been constructed and envisaged to explore different facets of neutrinos, in particular their masses and mixing.The Iron Calorimeter (ICAL) experiment at the India-based Neutrino Observatory (INO) [1] is one of the major detectors that is expected to see the light of the day soon. It will have unique features like the ability to distinguish muon neutrinos from antineutrinos at GeV energies, and measure the energies of hadrons in the same energy range. It is therefore well suited for the identification of neutrino mass hierarchy, the measurement of neutrino mixing parameters, and many probes of new physics. The site for the INO has been identified, and the construction is expected to start soon. In the meanwhile, the R&D for the ICAL detector, including the design of its modules, the magnet coils, the active detector elements and the associated electronics, has been underway over the past deca...

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