Large Non-perturbative Effects of Small \Delta m^2_{21}/\Delta m^2_{31} and \sin \theta_{13} on Neutrino Oscillation and CP Violation in Matter

In the framework of three generations, we consider the CP violation in neutrino oscillation with matter effects. At first, we show that the non-perturbative effects of two small parameters, \Delta m_{21}^2/\Delta m_{31}^2 and \sin \theta_{13}, become more than 50% in certain ranges of energy and baseline length. This means that the non-perturbative effects should be considered in detailed analysis in the long baseline experiments. Next, we propose a method to include these effects in approximate formulas for oscillation probabilities. Assuming the two natural conditions, \theta_{23}=45^\circ and the fact that the matter density is symmetric, a set of approximate formulas, which involve the non-perturbative effects, has been derived in all channels.Comment: 25 pages, 4 figures, version to appear in JHE

Very Long Baseline Neutrino Oscillation Experiment for Precise Measurements of Mixing Parameters and CP Violating Effects

We analyze the prospects of a feasible, Brookhaven National Laboratory based, very long baseline (BVLB) neutrino oscillation experiment consisting of a conventional horn produced low energy wide band beam and a detector of 500 kT fiducial mass with modest requirements on event recognition and resolution. Such an experiment is intended primarily to determine CP violating effects in the neutrino sector for 3-generation mixing. We analyze the sensitivity of such an experiment. We conclude that this experiment will allow determination of the CP phase $\delta_{CP}$ and the currently unknown mixing parameter $\theta_{13}$, if $\sin ^2 2 \theta_{13} \geq 0.01$, a value $\sim 15$ times lower than the present experimental upper limit. In addition to $\theta_{13}$ and $\delta_{CP}$, the experiment has great potential for precise measurements of most other parameters in the neutrino mixing matrix including $\Delta m^2_{32}$, $\sin^2 2\theta_{23}$, $\Delta m^2_{21}\times \sin 2 \theta_{12}$, and the mass ordering of neutrinos through the observation of the matter effect in the $\nu_\mu \to \nu_e$ appearance channel.Comment: 12 pages, 10 figure

Tests of the Standard Model Using Muon Polarization Asymmetries in Kaon Decays

We have examined the physics and the experimental feasibility of studying various kaon decay processes in which the polarization of a muon in the final state is measured. Valuable information on CP violation, the quark mixing (CKM) matrix, and new physics can be obtained from such measurements. We have considered muon polarization in K_L to mu+ mu- and K to pi mu+ mu- decays. Although the effects are small, or difficult to measure because of the small branching ratios involved, these studies could provide clean measurements of the CKM parameters. The experimental difficulty appears comparable to the observation of K to pi nu barnu. New sources of physics, involving non-standard CP violation, could produce effects observable in these measurements. Limits from new results on the neutron and electron electric dipole moment, and epsilon-prime over epsilon in neutral kaon decays, do not eliminate certain models that could contribute to the signal. A detailed examination of muon polarization out of the decay plane in KMU3 and radiative KMU2 decays also appears to be of interest. With current kaon beams and detector techniques, it is possible to measure the T-violating polarization for KMU3 with uncertainties approaching 0.0001. This level of sensitivity would provide an interesting probe of new physics.Comment: 24 pages, 3 figures, To be published in the International Journal of Modern Physics

T-odd correlations in charged Kl4 decays

We analyse the sensitivity to physics beyond the SM of T-odd correlations in $K_{\ell 4}$ decays, which do not involve the lepton polarization. We show that a combined analysis of $K^+_{\mu 4}$ and $K^-_{\mu 4}$ decays can lead to new constraints about CP violation in $\Delta S=1$ charged-current interactions, complementary to those obtained from the transverse muon polarization in $K_{\mu 3}$ and of comparable accuracy.Comment: 6 pages (LaTeX

Experiment Simulation Configurations Used in DUNE CDR

The LBNF/DUNE CDR describes the proposed physics program and experimental design at the conceptual design phase. Volume 2, entitled The Physics Program for DUNE at LBNF, outlines the scientific objectives and describes the physics studies that the DUNE collaboration will perform to address these objectives. The long-baseline physics sensitivity calculations presented in the DUNE CDR rely upon simulation of the neutrino beam line, simulation of neutrino interactions in the far detector, and a parameterized analysis of detector performance and systematic uncertainty. The purpose of this posting is to provide the results of these simulations to the community to facilitate phenomenological studies of long-baseline oscillation at LBNF/DUNE. Additionally, this posting includes GDML of the DUNE single-phase far detector for use in simulations. DUNE welcomes those interested in performing this work as members of the collaboration, but also recognizes the benefit of making these configurations readily available to the wider community.Comment: 9 pages, 4 figures, configurations in ancillary file

Search for the Weak Decay of an H Dibaryon

We have searched for a neutral $H$ dibaryon decaying via $H\to\Lambda n$ and $H\to\Sigma^0 n$. Our search has yielded two candidate events from which we set an upper limit on the $H$ production cross section. Normalizing to the inclusive $\Lambda$ production cross section, we find $(d\sigma_H/d\Omega) / (d\sigma_\Lambda/d\Omega) < 6.3\times 10^{-6}$ at 90% C.L., for an $H$ of mass $\approx$ 2.15 GeV/$c^2$.Comment: 11 pages, 6 postscript figures, epsfig, aps, preprint, revte

Potential of optimized NOvA for large theta(13) & combined performance with a LArTPC & T2K

NOvA experiment has reoptimized its event selection criteria in light of the recently measured moderately large value of theta(13). We study the improvement in the sensitivity to the neutrino mass hierarchy and to leptonic CP violation due to these new features. For favourable values of deltacp, NOvA sensitivity to mass hierarchy and leptonic CP violation is increased by 20%. Addition of 5 years of neutrino data from T2K to NOvA more than doubles the range of deltacp for which the leptonic CP violation can be discovered, compared to stand alone NOvA. But for unfavourable values of deltacp, the combination of NOvA and T2K are not enough to provide even a 90% C.L. hint of hierarchy discovery. Therefore, we further explore the improvement in the hierarchy and CP violation sensitivities due to the addition of a 10 kt liquid argon detector placed close to NOvA site. The capabilities of such a detector are equivalent to those of NOvA in all respects. We find that combined data from 10 kt liquid argon detector (3 years of nu + 3 years of nubar run), NOvA (6 years of nu + 6 years of nubar run) and T2K (5 years of nu run) can give a close to 2 sigma hint of hierarchy discovery for all values of deltacp. With this combined data, we can achieve CP violation discovery at 95% C.L. for roughly 60% values of deltacp.Comment: 22 pages, 24 pdf figures, 5 tables. In the appendix, new results are presented with conservative choices of central values of oscillation parameters. New references are added. Accepted in JHE