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.
Neutrino-neutrino interactions in dense neutrino streams, like those emitted by a core-collapse supernova, can lead to self-induced neutrino flavor
The recent Belle and BaBar measurements of the branching ratio of $B^+ to tau^+ u_tau$ indicate a significant deviation from the Standard Model prediction. We demonstrate that this measurement has a serious impact on models with minimal flavor viola
tion involving a charged Higgs boson, ruling out a large portion of the currently-allowed parameter space. In the constrained minimal supersymmetric standard model, this creates a tension between the measurements of $B^+ to tau^+ u_tau$ and the anomalous magnetic moment of the muon, unless $tanbeta$ is small, $mu > 0$, and $A_0$ takes a large negative value. In fact, a very small region of the parameter space of this model, with small values of $m_0$ and $m_{1/2}$, survives all the constraints at 95% C.L.. It is remarkable that this specific region is still consistent with the lightest supersymmetric particle as the dark matter. Moreover, it predicts observable SUSY signals in the early runs of the LHC, even perhaps at 7 TeV. We also show that a consistent explanation for the deviation of the $B^+ to tau^+ u_tau$ branching ratio from the Standard Model can be achieved in a non-universal Higgs mass model, which could also predict early signals of supersymmetry at the LHC.
In the scenario with four quark generations, we perform a fit using flavor-physics data and determine the allowed values -- preferred central values and errors -- of all of the elements of the 4X4 quark mixing matrix. In addition to the direct measur
ements of some of the elements, we include in the fit the present measurements of several flavor-changing observables in the K and B systems that have small hadronic uncertainties, and also consider the constraints from the vertex corrections to Z -> b bbar. The values taken for the masses of the fourth-generation quarks are consistent with the measurements of the oblique parameters and perturbativity of the Yukawa couplings. We find that |{tilde V}_{tb}| >= 0.98 at 3sigma, so that a fourth generation cannot account for any large deviation of |{tilde V}_{tb}| from unity. The fit also indicates that all the new-physics parameters are consistent with zero, and the mixing of the fourth generation with the other three is constrained to be very small: we obtain |{tilde V}_{ub}| < 0.06, |{tilde V}_{cb}| < 0.027, and |{tilde V}_{tb}| < 0.31 at 3sigma. Still, this does allow for the possibility of new-physics signals in Bd, Bs and rare K decays.
We summarize our current understanding of the neutrino flavor
We point out possible features of neutrino spectra from a future galactic core collapse supernova that will enhance our understanding of neutrino mixing as well as supernova astrophysics. We describe the neutrino flavor
The neutrino burst from a galactic supernova can help determine the neutrino mass hierarchy and $theta_{13}$, and provide crucial information about supernova astrophysics. Here we review our current understanding of the neutrino burst, flavor
Symmetry-based ideas, such as the quark-lepton complementarity (QLC) principle and the tri-bimaximal mixing (TBM) scheme, have been proposed to explain the observed mixing pattern of neutrinos. We argue that such symmetry relations need to be imposed
at a high scale $Lambda sim 10^{12}$ GeV characterizing the large masses of right-handed neutrinos required to implement the seesaw mechanism. For nonhierarchical neutrinos, renormalisation group evolution down to a laboratory energy scale $lambda sim 10^3$ GeV tends to radiatively break these symmetries at a significant level and spoil the mixing pattern predicted by them. However, for Majorana neutrinos, suitable constraints on the extra phases $alpha_{2,3}$ enable the retention of those high scale mixing patterns at laboratory energies. We examine this issue within the Minimal Supersymmetric Standard Model (MSSM) and demonstrate the fact posited above for t
We investigate new physics models that can increase the lifetime differences in the $B_q$--$bar{B}_q$ systems ($q = d,s$) above their standard model values. If both $B_q$ as well as $bar{B}_q$ can decay to a final state through flavour dependent new
physics interactions, the so-called Grossman bound may be evaded. As examples, we consider the scalar leptoquark model and $lambda$-type R-parity violating supersymmetry. We find that models with a scalar leptoquark can enhance $DeltaGamma_s/Gamma_s$ all the way up to its experimental upper bound and $DeltaGamma_d/Gamma_d$ to as much as $sim 2.5%$, at the same time allowing the CP violating phase $beta_s$ to vary between $- 45^circ$ and $20^circ$. R-parity violating supersymmetry models cannot enhance the lifetime differences significantly, but can enhance the value of $beta_s$ up to $sim pm 20^circ$. This may bring the values of $DeltaGamma_q/Gamma_q$ as well as $beta_s$ within the measurement capabilities of $B$ factories and LHCb. We also obtain bounds on combinations of these new physics couplings, and predict enhanced branching ratios of $B_{s/d} to tau^+ tau^-$.
