Comments on Neutrino Tests of Special Relativity

We point out that the assumption of Lorentz noninvariance examined recently by Coleman and Glashow leads to neutrino flavor oscillations which are phenomenologically equivalent to those obtained by assuming the neutrinos violate the principle of equivalence. We then comment on the limits on Lorentz noninvariance which can be derived from solar, atmospheric, and accelerator neutrino experiments.Comment: 5 pages, Revte

Imprints of the nuclear symmetry energy on gravitational waves from the axial w-modes of neutron stars

The eigen-frequencies of the axial w-modes of oscillating neutron stars are studied using the continued fraction method with an Equation of State (EOS) partially constrained by the recent terrestrial nuclear laboratory data. It is shown that the density dependence of the nuclear symmetry energy $E_{sym}(\rho)$ affects significantly both the frequencies and the damping times of these modes. Besides confirming the previously found universal behavior of the mass-scaled eigen-frequencies as functions of the compactness of neutron stars, we explored several alternative universal scaling functions. Moreover, the $w_{II}$-mode is found to exist only for neutron stars having a compactness of $M/R\geq 0.1078$ independent of the EOS used.Comment: Version appeared in Phys. Rev. C80, 025801 (2009

Comment on ``Neutrino masses and mixing angles in a predictive theory of fermion masses''

In the extension of the Dimopoulos--Hall--Raby model of the fermion mass matrices to the neutrino sector, there is an entry in the up-quark and neutrino Dirac mass matrices which can be assumed to arise from the Yukawa coupling of a {\bf 120}, instead of a {\bf 10} or a {\bf 126}, of SO(10). Although this assumption leads to an extra undetermined complex parameter in the model, the resulting lepton mixing matrix exhibits the remarkable feature that the $\nu_{\tau}$ does not mix with the other two neutrinos. Making a reasonable assumption about the extra parameter, we are able to fit the large-mixing-angle MSW solution of the solar-neutrino problem, and we obtain $m_{\nu_{\tau}} \sim 10$ eV, the right mass range to close the Universe. Other possibilities for explaining the solar-neutrino deficit are also discussed.Comment: standard LATEX, 6 pages, 2 figures available from the authors, report No. CMU-HEP93-20 and DOE-ER/40682-4

New Constraints on Neutrino Oscillations in Vacuum as a Possible Solution of the Solar Neutrino Problem

Two-neutrino oscillations in vacuum are studied as a possible solution of the solar neutrino problem. New constraints on the parameter sn2, characterizing the mixing of the electron neutrino with another active or sterile neutrino, as well as on the mass--squared difference, dm2, of their massive neutrino components, are derived using the latest results from the four solar neutrino experiments. Oscillations into a sterile neutrino are ruled out at 99 % C.L. by the observed mean event rates even if one includes the uncertainties of the standard solar model predictions in the analysis.Comment: 10 pages + 3 figures attached as postscript files, IFP-480-UNC and Ref. SISSA 177/93/EP (Updated Version which takes into account the latest GALLEX results from 30 runs

Constraining a possible time variation of the gravitational constant G with terrestrial nuclear laboratory data

Testing the constancy of the gravitational constant G has been a longstanding fundamental question in natural science. As first suggested by Jofr\'{e}, Reisenegger and Fern\'{a}ndez [1], Dirac's hypothesis of a decreasing gravitational constant $G$ with time due to the expansion of the Universe would induce changes in the composition of neutron stars, causing dissipation and internal heating. Eventually, neutron stars reach their quasi-stationary states where cooling due to neutrino and photon emissions balances the internal heating. The correlation of surface temperatures and radii of some old neutron stars may thus carry useful information about the changing rate of G. Using the density dependence of the nuclear symmetry energy constrained by recent terrestrial laboratory data on isospin diffusion in heavy-ion reactions at intermediate energies and the size of neutron skin in $^{208}Pb$ within the gravitochemical heating formalism, we obtain an upper limit of the relative changing rate of $|\dot{G}/G|\le4\times 10^{-12}yr^{-1}$ consistent with the best available estimates in the literature.Comment: 27 pages, 11 figures, and 2 tables. Accepted version to appear in PRC (2007

A Study of the Day - Night Effect for the Super - Kamiokande Detector: I. Time Averaged Solar Neutrino Survival Probability

This is the first of two articles aimed at providing comprehensive predictions for the day-night (D-N) effect for the Super-Kamiokande detector in the case of the MSW \nu_e \to \numt transition solution of the solar neutrino problem. The one-year averaged probability of survival of the solar \nue crossing the Earth mantle, the core, the inner 2/3 of the core, and the (core + mantle) is calculated with high precision (better than 1%) using the elliptical orbit approximation (EOA) to describe the Earth motion around the Sun. Results for the survival probability in the indicated cases are obtained for a large set of values of the MSW transition parameters $\Delta m^2$ and $sin^22\theta_{V}$ from the ``conservative'' regions of the MSW solution, derived by taking into account possible relatively large uncertainties in the values of the $^{8}$B and $^{7}$Be neutrino fluxes. Our results show that the one-year averaged D-N asymmetry in the $\nu_e$ survival probability for neutrinos crossing the Earth core can be, in the case of $sin^22 \theta_{V} \leq 0.13$, larger than the asymmetry in the probability for (only mantle crossing + core crossing) neutrinos by a factor of up to six. The enhancement is larger in the case of neutrinos crossing the inner 2/3 of the core. This indicates that the Super-Kamiokande experiment might be able to test the $sin^22\theta_{V} \leq 0.01$ region of the MSW solution of the solar neutrino problem by performing selective D-N asymmetry measurements.Comment: LaTeX2e - 18 Text Pages + 21 figures = 39 Pages. - Figures in PS + text file sk1b14.tex requires two auxiliary files (included

How Well Do We (and Will We) Know Solar Neutrino Fluxes and Oscillation Parameters?

Assuming neutrino oscillations occur, the pp electron neutrino flux is uncertain by at least a factor of two, the ${\rm ^8B}$ flux by a factor of five, and the ${\rm ^7Be}$ flux by a factor of forty-five. Calculations of the expected results of future solar neutrino experiments (SuperKamiokande, SNO, BOREXINO, ICARUS, HELLAZ, and HERON) are used to illustrate the extent to which these experiments will restrict the range of the allowed neutrino mixing parameters. We present an improved formulation of the ``luminosity constraint'' and show that at 95\% confidence limit this constraint establishes the best available limits on the rate of creation of pp neutrinos in the solar interior and provides the best upper limit to the ${\rm ^7Be}$ neutrino flux.Comment: 37 pages, uuencoded Z-compressed postscript file (with figures); Submitted to Physical Review

Pattern formation during electrodeposition of copper-antimony alloys

Aim of the present study is to establish the conditions of the electrolysis for the preparation of structured and unstressed purple-pink coatings of copper-antimony alloys, including their phase characterization. Also the task of the present investigation is, by changing drastically the metal content in the methanesulfonic electrolyte to find out the conditions of electrolysis where the self-organization of the different phases is expressed by higher-order structures - not only waves but also spirals and targets. The possibility to obtain copper-antimony alloy with up to 80 wt. % Sb from methanesulfonic acid is shown. The deposition rate, morphology and the phase composition of the obtained coatings are established. The phenomena of formation of spatio-temporal structures in this alloy are described.It is determined that the observed structures consist of Cu2Sb and Cu11Sb3 intermetallic phases

Chizhov and Petcov Reply

We have found in [1] new conditions for a total neutrino conversion in the case of neutrino oscillations taking place in a medium, consisting of n = 2 (or 3) alternating layers with constant densities $N_1$ and $N_2$. It is claimed in [4] that our results are particular case of enhancement of neutrino oscillations, which was suggested earlier by other authors and was widely discussed in the literature. We refute these claims, confirming the novelty of our results.Comment: 2 pages, LATEX; concise (essentially 1 page) and somewhat modified version of Ref. SISSA 5/2000/EP (hep-ph/0003110); reply on the ``Comment on New Conditions for a Total Neutrino Conversion in a Medium'', Phys. Rev. Lett. 85 (2000) 3978; published as ``Chizhov and Petcov Reply'' in Phys. Rev. Lett. 85 (2000) 397