Non-Oscillation Searches of Neutrino Mass in the Age of Oscillations

We focus on the implications of the oscillations for the shape of nuclear beta-spectrum (=direct search for nu mass). This is of interest because of the existing bound, m_(nu_e)<2.2 eV, that could improve by one order of magnitude with future experiments. We stress important connections with the results of Liquid Scintillator Neutrino Detector, nu_e disappearance experiments, supernova neutrinos and neutrinoless double beta decay.Comment: 3 pages, 1 figure. Matches the version to appear in the Proceedings of NOW 2000 Worksho

Is the LMA solar-neutrino solution ruled out by SN1987A data?

The development of new supernova neutrino detectors relies on the expected hard energy spectrum of the nu_mu and nu_tau emitted in the supernova. We show that SN1987A was sensitive to the large mixing angle (LMA) and "just so" solution to the solar neutrino problem. We review the previous analysis of the SN1987A data and propose a new analysis. The results of this analysis strongly disfavor the LMA solution, provided the nu_mu and nu_tau are hard as predictedComment: 4 pages; 6 figures. Presented at the Europhysics Neutrino Oscillation Workshop, NOW 2000 (EPS, Lecce, Italy, Sept. 9-16, 2000) and to be published in Nucl. Phys. B (PS) (North Holland, Amsterdam, 2001

The SuperNova Early Warning System

A core collapse in the Milky Way will produce an enormous burst of neutrinos in detectors world-wide. Such a burst has the potential to provide an early warning of a supernova's appearance. I will describe the nature of the signal, the sensitivity of current detectors, and SNEWS, the SuperNova Early Warning System, a network designed to alert astronomers as soon as possible after the detected neutrino signal.Comment: 3 pages, appearing in refereed proceedings of "Hotwiring the Transient Universe 2007", eds. A. Allan, J. S. Bloom, R. Seaman, Astron. Nachr. vol. 329, March 200

SNO and Supernovae

The Sudbury Neutrino Observatory (SNO) has unique capabilities as a supernova detector. In the event of a galactic supernova there are opportunities, with the data that SNO would collect, to constrain certain intrinsic neutrino properties significantly, to test details of the various models of supernova dynamics, and to provide prompt notification to the astronomical community through the Supernova Early Warning System (SNEWS). This paper consists of a discussion of these opportunities illustrated by some preliminary Monte Carlo results.Comment: 7 pages, latex, 3 eps figures, Invited paper at Neutrino Oscillations Workshop (NOW 2000), Otranto, Italy, September 9-16, 2000, to be published in the Proceeding

Laser-induced electron emission from a tungsten nanotip: identifying above threshold photoemission using energy-resolved laser power dependencies

We present an experiment studying the interaction of a strongly focused 25 fs laser pulse with a tungsten nanotip, investigating the different regimes of laser-induced electron emission. We study the dependence of the electron yield with respect to the static electric field applied to the tip. Photoelectron spectra are recorded using a retarding field spectrometer and peaks separated by the photon energy are observed with a 45 % contrast. They are a clear signature of above threshold photoemission (ATP), and are confirmed by extensive spectrally resolved studies of the laser power dependence. Understanding these mechanisms opens the route to control experiment in the strong-field regime on nanoscale objects.Comment: 9 pages, 6 figure

Evidence for two neutrino mass eigenstates from SN 1987A and the possibility of superluminal neutrinos

This paper reports a new phenomenological analysis of the neutrino burst detected from SN 1987 A, and it reveals the presence of two mass eigenstates. The heavier mass eigenstate has $m_H=21.4 \pm 1.2 eV/c^2$, while the lighter one has $m_L=4.0 \pm0.5 eV/c^2$. It is not the first paper to make such a claim, but it expands on a 1988 conditional analysis by Cowsik, and it attempts to make the evidence more robust through an improved statistical analysis, and through providing reasons why alternative explanations are unlikely. It also shows how the result can be made consistent with existing smaller electron neutrino mass limits with the existence of a third tachyonic (superluminal) mass eigenstate.Comment: 11 pages, 2 figure

Limits on leptonic photon interactions from SN1987a

If massless leptonic photons associated to electron, muon or tau leptonic number exist they would have been emitted from supernova 1987a via the annihilation process $\nu\bar{\nu}\to\gamma_{l}\gamma_{l}$. By requiring that this process does not carry away most of the energy that can be radiated by the supernova we obtain an upper limit on the leptonic photon coupling constants, $\alpha_{l} < 5.4 \times 10^{-11}$. Under certain assumptions about $\gamma_{l}$ - trapping conditions we find that the region of $\alpha_{l} = 10^{-8} - 10^{-7}$ might be of interest for an experimental search for leptonic photons.Comment: 6 pages, AmSTex, LaTex. The limits are revised for neutrino chemical potential $\mu$ = 0. The new limits do not differ significantly from the original one. To be published in Phys.Lett.

Cosmological bounds on tachyonic neutrinos

Recent time-of-flight measurements on muon neutrinos in the OPERA neutrino oscillation experiment have found anomalously short times compared to the light travel-times, corresponding to a superluminal velocity, $v-1=2.37\pm0.32\times 10^{-5}$ in units where $c=1$. We show that cosmological bounds rule out an explanation involving a Lorentz invariant tachyonic neutrino. At the OPERA energy scale, nucleosynthesis constraints imply $v-1<0.86\times 10^{-12}$ and the Cosmic Microwave Background observations imply $v-1<7.1\times 10^{-23}$. The CMB limit on the velocity of a tachyon with an energy of 10 MeV is stronger than the SN1987A limit. Superluminal neutrinos that could be observed at particle accelerator energy scales would have to be associated with Lorentz symmetry violation.Comment: LaTeX, 4 page

Few body Calculation of Neutrino Neutral Inelastic scattering on 4He

The inelastic neutral reaction of neutrino on 4He is calculated using two modern nucleon--nucleon potentials. Full final state interaction among the four nucleons is considered, via the Lorentz integral transform (LIT) method. The effective interaction hyperspherical-harmonic (EIHH) approach is used to solve the resulting Schrodinger like equations. A detailed energy dependent calculation is given in the impulse approximation.Comment: 4 pages; talk at 18th International Conference on Few-Body Problems in Physics (FB18), Santos, SP, Brazil, August 200