Abstract: We examine the impact of Lorentz Invariance Violation (LIV) in measuring the octant of theta(23) and CP phases in the context of the Deep Underground Neutrino Experiment (DUNE). We consider the CPT-violating LIV parameters involving e-mu(a(e mu)) and e-tau (a(e tau)) flavors, which induce an additional interference term in neutrino and antineutrino appearance probabilities. This newinterference term depends on both the standard CP phase delta and the new dynamical CP phase phi(e mu)/phi(e tau), giving rise to new degeneracies among (theta(23), delta, phi). Taking one LIV parameter at-a-time and considering a small value of vertical bar a(e mu)vertical bar = vertical bar a(e tau)vertical bar = 5 x 10(-24) GeV, we find that the octant discovery potential of DUNE gets substantially deteriorated for unfavorable combinations of delta and phi(e mu)/phi(e tau). The octant of theta(23) can only be resolved at 3 sigma if the true value of sin(2) theta(23) less than or similar to 0.42 or >= 0.62 for any choices of delta and phi. Interestingly, we also observe that when both the LIV parameters a(e mu) and a(e tau) are present together, they cancel out the impact of each other to a significant extent, allowing DUNE to largely regain its octant resolution capability. We also reconstruct the CP phases delta and phi(e mu)/phi(e tau). The typical 1 sigma uncertainty on delta is 10-15 degrees. and the same on phi(e mu)/phi(e tau) is 25-30 degrees depending on the choices of their true values.

Abstract: Recent data from long-baseline neutrino oscillation experiments have provided new information on theta(13), hinting that 0.01 less than or similar to sin(2) 2 theta(13) less than or similar to 0.1 at 2 sigma confidence level. In the near future, further confirmation of this result with high significance will have a crucial impact on the optimization of the future long-baseline neutrino oscillation experiments designed to probe the neutrino mass ordering and leptonic CP violation. In this context, we expound in detail the physics reach of an experimental setup where neutrinos produced in a conventional wide-band beam facility at CERN are observed in a proposed Giant Liquid Argon detector at the Pyhasalmi mine, at a distance of 2290 km. Due to the strong matter effects and the high detection efficiency at both the first and second oscillation maxima, this particular setup would have unprecedented sensitivity to the neutrino mass ordering and leptonic CP violation in the light of the emerging hints of large theta(13). With a 10 to 20 kt 'pilot' detector and just a few years of neutrino beam running, the neutrino mass hierarchy could be determined, irrespective of the true values of delta(CP) and the mass hierarchy, at 3 sigma (5 sigma) confidence level if sin(2) 2 theta(13)(true) = 0.05 (0.1). With the same exposure, we start to have 3 sigma sensitivity to CP violation if sin(2) 2 theta(13)(true) > 0.05, in particular testing maximally CP-violating scenarios at a high confidence level. After optimizing the neutrino and anti-neutrino running fractions, we study the performance of the setup as a function of the exposure, identifying three milestones to have roughly 30%, 50% and 70% coverage in delta(CP) (true) for 3 sigma CP violation discovery. For comparison, we also study the CERN to Slanic baseline of 1540 km. This work nicely demonstrates that an incremental program, staged in terms of the exposure, can achieve the desired physics goals within a realistically feasible timescale, and produce significant new results at each stage.