The science potential of a 10 kiloton deep-ocean liquid scintillation detector for ~1 MeV energy scale electron anti-neutrinos has been studied. Such an instrument, designed to be portable and function in the deep ocean (3-5 km) can make unique measu
rements of the anti-neutrinos from radioactive decays in the Earth.s mantle. Ths information speaks to some of the most fundamental questions in geology about the origin of the Earth, plat e tectonics, the geomagnetic field and even somewhat indirectly to global warming. Measurements in multiple locations will strengthen the potential insights. On the particle physics side, we have identified a unique role in the study of anti-neutrinos from a nuclear power complex, at a range of 55-60 km off shore. Not only can precision measurements be made of most neutrino mixing parameters, including $theta_{13}$ (depending on magnitude), but the neutrino mass hierarchy can be determined in a method not heretofore discussed, and one which does not rely upon matter effects. This detector is under active study on paper, in the laboratory, and at sea. An interdisciplinary and international collaboration is in formation, and plans are in motion for a major proposal, to be followed by construction over several years.
We propose that a sufficiently advanced civilization may employ Cepheid variable stars as beacons to transmit all-call information throughout the galaxy and beyond. One can construct many scenarios wherein it would be desirable for such a civilizatio
n of star ticklers to transmit data to anyone else within viewing range. The beauty of employing Cepheids is that these stars can be seen from afar(we monitor them out through the Virgo cluster), and any developing technological society would seem to be likely to closely observe them as distance markers. Records exist of Cepheids for well over one hundred years. We propose that these (and other regularly variable types of stars) be searched for signs of phase modulation (in the regime of short pulse duration) and patterns, which could be indicative of intentional signaling.
It is shown how high energy neutrino beams from very distant sources can be utilized to learn about many properties of neutrinos such as lifetimes, mass hierarchy, mixing, minuscule pseudo-Dirac mass splittings; in addition, the production mechanism
of neutrinos in astrophysical sources can also be elucidated.
Current experimental data on neutrino mixing are very well described by TriBiMaximal mixing. Accordingly, any phenomenological parametrization of the MNSP matrix must build upon TriBiMaximal mixing. We propose one particularly natural parametrization
, which we call TriMinimal. The three small deviations of the PDG angles from their TriBiMaximal values, and the PDG phase, parametrize the TriMinimal mixing matrix. As an important example of the utility of this new parametrization, we present the simple resulting expressions for the flavor-mixing probabilities of atmospheric and astrophysical neutrinos. As no foreseeable experiment will be sensitive to more than second order in the small parameters, we expand these flavor probabilities to second order.
Using a recent estimate of the velocity of pulsars arising from neutrinos emitted with modified URCA processes with electrons in Landua levels, and the temperture of the protoneutron star created by SN1987A, derived from the energy of the observed ne
utrinos, we predict the velocity of the resulting pulsar.
We discuss flavor-mixing probabilities and flavor ratios of high energy astrophysical neutrinos. In the first part of this paper, we expand the neutrino flavor-fluxes in terms of the small parameters U_{e3} and pi/4 - theta_{23}, and show that there
are universal first and second order corrections. The second order term can exceed the first order term, and so should be included in any analytic study. We also investigate the probabilities and ratios after a further expansion around the tribimaximal value of sin^2 theta_{12} = 1/3. In the second part of the paper, we discuss implications of deviations of initial flavor ratios from the usually assumed, idealized flavor compositions for pion, muon-damped, and neutron beam sources, viz., (1 : 2 : 0), (0 : 1 : 0), and (1 : 0 : 0), respectively. We show that even small deviations have significant consequences for the observed flavor ratios at Earth. If initial flavor deviations are not taken into account in analyses, then false inferences for the values in the PMNS matrix elements (angles and phase) may result.
We study baryon number violating nucleon decays induced by unparticle interactions with the standard model particles. We find that the lowest dimension operators which cause nucleon decays can arise at dimension 6 + (d_s-3/2) with the unparticles bei
ng a spinor of dimension d_s=d_U +1/2. For scalar and vector unparticles of dimension d_U, the lowest order operatoers arise at 6+d_U and 7+d_U dimensions,respectively. Comparing the spinor unparticle induced n to O^s_U and experimental bound on invisible decay of a neutron from KamLAND, we find that the scale for unparticle physics is required to be larger than 10^{10} GeV for d_U < 2 if the couplings are set to be of order one. For scalar and vector unparticles, the dominant baryon number violating decay modes are nto bar u + O_U (O^mu_U) and p to e^+ + O_U (O^mu_U). The same experimental bound puts the scales for scalar and vector unparticle to be larger than 10^{7} and 10^{5} GeV for d_U <2 with couplings set to be of order one. Data on, p to e^+ invisible, puts similar constraints on unparticle interactions.
We discuss causality properties of extra-dimensional theories allowing for effectively superluminal bulk shortcuts. Such shortcuts for sterile neutrinos have been discussed as a solution to the puzzling LSND and MiniBooNE neutrino oscillation results
. We focus here on the sub-category of asymmetrically warped brane spacetimes and argue that scenarios with two extra dimensions may allow for timelike curves which can be closed via paths in the extra-dimensional bulk. In principle sterile neutrinos propagating in the extra dimension may be manipulated in a way to test the chronology protection conjecture experimentally.
We provide a comprehensive, up-to-date analysis of possible New Physics contributions to the mass difference $Delta M_D$ in $D^0$-${bar D}^0$ mixing. We consider the most general low energy effective Hamiltonian and include leading order QCD running
of effective operators. We then explore an extensive list of possible New Physics models that can generate these operators, which we organize as including Extra Fermions, Extra Gauge Bosons, Extra Scalars, Extra Space Dimensions and Extra Symmetries. For each model we place restrictions on the allowed parameter space using the recent evidence for observation of $D$ meson mixing. In many scenarios, we find strong constraints that surpass those from other search techniques and provide an important test of flavor changing neutral currents in the up-quark sector. We also review the recent BaBar and Belle findings, and describe the current status of the Standard Model predictions of $D^0$-${bar D}^0$ mixing.
