T-violation search with very long baseline neutrino oscillation experiments

Abstract

We consider possibilities of observing T-violation effects in neutrino oscillation experiments with a very long baseline (ϳ10000 km) using a low energy neutrino (ϳ several hundreds MeV͒. We show that the matter effect effectively changes only the first-second generation mixing angle, respecting solar neutrino deficits and atmospheric neutrino anomalies. The effective mixing of the first-second generation in the Earth grows up to maximum by resonance. This effect enables one to search T-violation in case the first-second mixing angle is small. We discuss its implications to the observations of T-violation effects in long baseline experiments.

Energy dependence of K − -“pp” effective potential derived from coupled-channel Green’s function

“…If we use CC Green's functions in Eq. (2), we expect to confirm the previous results [3,4] for the 3 He(in-flight K − , n) spectrum within the DWIA calculation. Now we define the K − -"pp" equivalent local potential for channel 1,Ũ eff 11 as…”

“…In the single-channel framework, we have shown that behavior of the 3 He(inflight K − , n) spectrum can be understood in the "moving pole" picture [4]; a pole of the K − pp bound state moves in the complex energy plane as a function of the energy E on the real axis because the K − -"pp" effective potential is considerably energy-dependent. A trajectory of its moving pole governs the shape of the spectrum.…”

“…In this article, we investigate a single-channel K − -"pp" equivalent local potential which is derived from CC Green's functions for K − (pp)-π(Σ N) systems, and evaluate the energy dependence of this effective potential to be compared with a phenomenological one [4] which is determined within Eq. (1).…”

“…We theoretically have discussed the expected inclusive and semi-exclusive spectra for the 3 He(in-flight K − , n) reaction within the framework of the distorted-wave impulse approximation (DWIA) . We have employed a phenomenological single-channel K − -"pp" (complex) effective potential between the K − and the "pp"-core nucleus [3,4], which has the form of where V 0 and W 0 are strength parameters in real and imaginary parts, respectively, and b is the range parameter. f (E) is the phase space suppression factor of the K − pp → πΣ N decay modes [5] where E is the energy measured from the K − pp threshold.…”

Critical gravitational collapse of a perfect fluid: Nonspherical perturbations

“…The spherically symmetric fluid with κ = 1/3, corresponding to an ultrarelativistic gas, was one of the first systems in which critical phenomena were found [4]. These results were later extended to the range 0 < κ < 1 [5][6][7]. We now ask what happens when we allow small deviations from spherical symmetry.…”