Reconciling dark matter and solar neutrinos

We present a simple model for neutrino dark matter in which neutrino masses arise radiatively and the solar neutrino data are explained via the MSW effect. The dark matter scale arises at the one-loop level with the MSW scale arises only in two loops. The model is compatible with all observational facts and allows observable νeντ or νμντ oscillation rates in the laboratory if the limits from primordial big bang nucleosynthesis (BBN) are taken conservatively. In addition, it can be probed by searching for muon number violating processes such as μ→ e+ γ, and μ→3 e. These rates can well lie within the sensitivities of present experiments. Finally, if we ignore BBN limits we can have also a common explanation for the atmospheric neutrino deficit via νμ oscillations to a sterile neutrino νs with maximal mixing and 10 -2-10 -3 eV 2

THE ANIMAL WELFARE ACT IS LACKING: HOW TO UPDATE THE FEDERAL STATUTE TO IMPROVE ZOO ANIMAL WELFARE

Visiting the zoo is a beloved national pastime — American zoos attract 183 million people annually. For many Americans, zoos provide the first, and sometimes only, opportunity for individuals to be in the presence of animals outside of domesticated cats and dogs. However, for the animals themselves, zoos can cause suffering. Two philosophies support the protection of wild animals in captivity: an anthropocentric and ecocentric view. According to the former, anthropocentric view, wild animals hold an extrinsic value and when they cease to be valuable to humans, or conflict with our other values, their interests can be sacrificed. The latter, ecocentric view, holds that wild animals have intrinsic value, can be morally harmed, and how we treat them should not be judged solely by the benefit to humans of a particular course of action. This article is written from the philosophy that animals have an intrinsic value. It examines how zoos operate under the Animal Welfare Act and how it must be improved to better zoo animal welfare under the ecocentric view. Part II provides an overview of the Animal Welfare Act, under which all zoos must adhere and are licensed. Part III discusses issues with the Animal Welfare Act, focusing on the lack of enforcement, bare minimum care standards, the United States Department of Agriculture’s (“USDA”) failure to shut down non-compliant zoos, and the USDA’s secrecy regarding Animal Welfare Act violator documentation. Part IV discusses two zoo accreditation organizations that provide additional animal welfare guidance to zoos and offer membership status. Part V examines the problems with zoos, including individual animal psychological suffering in captivity and breeding programs, animal susceptibility to human diseases, exploitation of zoo animals for human entertainment, and potential harm to humans. Part VI examines suggestions for improvement to the Animal Welfare Act and the viability of these recommendations, assessing their practicality and sufficiency. This article concludes that the Animal Welfare Act should be amended with species specific guidelines, a prohibition on public contact with animals, a stricter licensing procedure, and a provision for the creation of USDA facilities to treat and house confiscated animals from non-compliant zoos. Without meaningful changes to the Animal Welfare Act, the animals will continue to suffer in sub-par conditions

Right Handed Weak Currents in Sum Rules for Axialvector Constant Renormalization

The recent experimental results on deep inelastic polarized lepton scattering off proton, deuteron and $^{3}$He together with polari% zed neutron $\beta$-decay data are analyzed. It is shown that the problem of Ellis-Jaffe and Bjorken sum rules deficiency and the neutron paradox could be solved simultaneously by assuming the small right handed current (RHC) admixture in the weak interaction Lagrangian. The possible RHC impact on pion-nucleon $\sigma$-term and Gamow-Teller sum rule for $(p,n)$ nuclear reactions is pointed out.Comment: to be published in Phys. Rev. Lett. LaTeX, 8 pages, 21 k

Third Generation Familons, B Factories, and Neutrino Cosmology

We study the physics of spontaneously broken family symmetries acting on the third generation. Massless familons (or Majorons) $f$ associated with such broken symmetries are motivated especially by cosmological scenarios with decaying tau neutrinos. We first note that, in marked contrast with the case for the first two generations, constraints on third generation familon couplings are poor, and are, in fact, non-existent at present in the hadronic sector. We derive new bounds from $B^0$--$\bar{B}^0$ mixing, $B^0 \to l^+ l'^-$, $b\to s\nu\bar{\nu}$, and astrophysics. The resulting constraints on familon decay constants are still much weaker than those for the first and second generation. We then discuss the promising prospects for significant improvements from searches for $\tau\to l f$, $B\to (\pi, K) f$, and $b\to (d,s) f$ with the current CLEO, ARGUS, and LEP data. Finally, we note that future constraints from CLEO III and the $B$ factories will probe decay constants beyond 10^8 GeV, well within regions of parameter space favored by proposed scenarios in neutrino cosmology.Comment: ReVTeX, 33 pages, 6 figures, notation improved, references added, revised to conform to pubished versio

Precision tau physics

Precise measurements of the lepton properties provide stringent tests of the Standard Model and accurate determinations of its parameters. We overview the present status of tau physics, highlighting the most recent developments, and discuss the prospects for future improvements. The leptonic decays of the tau lepton probe the structure of the weak currents and the universality of their couplings to the W boson. The universality of the leptonic Z couplings has also been tested through Z -> l(+)l(-) decays. The hadronic tau decay modes constitute an ideal tool for studying low-energy effects of the strong interaction in very clean conditions. Accurate determinations of the QCD coupling and the Cabibbo mixing V-us have been obtained with tau data. The large mass of the tau opens the possibility to study many kinematically-allowed exclusive decay modes and extract relevant dynamical information. Violations of flavour and CP conservation laws can also be searched for with tau decays. Related subjects such as μdecays, the electron and muon anomalous magnetic moments, neutrino mixing and B-meson decays into tau leptons are briefly covered. Being one the fermions most strongly coupled to the scalar sector, the tau lepton is playing now a very important role at the LHC as a tool to test the Higgs properties and search for new physics at higher scales

Spontaneous R-parity violation and the origin of neutrino mass

We study the phenomenology of supersymmetric models that explain neutrino masses through the spontaneous breaking of R-parity, finding strong correlations between the decays of the lightest neutralino and the neutrino mixing angles. In addition, the existence of a Goldstone boson, usually called Majoron ($J$), completely modifies the phenomenology with respect to the standard picture, inducing large invisible branching ratios and charged lepton decays, like $\mu \to e J$, interesting signals that can be used to constrain the model.Comment: 10 pages, 5 figures. To appear in the DISCRETE'08 proceeding

Left-handed neutrino disappearance probe of neutrino mass and character

We explore the sensitivity to a non vanishing neutrino mass offered by dynamical observables, i.e., branching ratios and polarizations. The longitudinal polarization in the C.M. frame decreases by a 4% for $D^+ \rightarrow \tau^+ \nu_\tau$ and $m_{\nu_\tau}=24$ MeV. Taking advantage of the fact that the polarization is a Lorentz variant quantity, we study the polarization effects in a boosted frame. By means of a neutrino beam, produced by a high velocity boosted parent able to flip the neutrino helicity, we find that an enhanced left-handed neutrino deficit, induced by a Wigner rotation, appears.Comment: 8 pages and 2 figures. Last version accepted in PRL, new references and better analysis of experimental possibilitie

Constraints from Precision Electroweak Data on Leptoquarks and Bileptons

Explicit expressions are derived for the oblique parameters $S$ and $T$ in certain extensions of the standard model. In particular, we consider leptoquarks and bileptons, and find phenomenological constraints on their allowed masses. Leptoquarks suggested by the neutral and charged current anomalies at HERA can give improved agreement with both $S$ and $T$. If bileptons are the only new states, the singly-charged one must be heavier than the directly-established lower limit. Finally, we study SU(15) grand unification and show that there are regions of parameter space where the theory is compatible with experimental data.Comment: 25 pages LaTeX including 7 figures. With improved comparison to experimental data and other update