9,107 research outputs found

    New vector-scalar contributions to neutrinoless double beta decay and constraints on R-parity violation

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    We show that in minimal supersymmetric standard model (MSSM) with R-parity breaking as well as in the left-right symmetric model, there are new observable contributions to neutrinoless double beta decay arising from hitherto overlooked diagrams involving the exchange of one W boson and one scalar boson. In particular, in the case of MSSM, the present experimental bounds on neutrinoless double beta decay lifetime improves the limits on certain R-parity violating couplings by about two orders of magnitude. It is shown that similar diagrams also lead to enhanced rates for Ό−→e+\mu^-\rightarrow e^+ conversion in nuclei, which are in the range accessible to ongoing experiments.Comment: Latex file; 9 pages; 3 figures available on reques

    The coupling constants for an electroweak model with a SU(4)PS⊗SU(4)EWSU(4)_{PS} \otimes SU(4)_{EW} unification symmetry

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    We introduce the sequence of spontaneous symmetry breaking of a coupling between Pati-Salam and electroweak symmetries SU(4)PS⊗SU(4)EWSU(4)_{PS} \otimes SU(4)_{EW} in order to establish a mathematically consistent relation among the coupling constants at grand unification energy scale. With the values of baryon minus lepton quantum numbers of known quarks and leptons, by including right-handed neutrinos, we can find the mixing angle relations at different energy levels up to the electromagnetic U(1)EMU(1)_{EM} scale.Comment: 8 page

    Lepton Flavor Violation and the Tau Neutrino Mass

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    We point out that, in the left-right symmetric model of weak interaction, if Μτ\nu_\tau mass is in the keV to MeV range, there is a strong correlation between rare decays such as τ→3ÎŒ,τ→3e\tau \rightarrow 3 \mu, \tau \rightarrow 3 e and the Μτ\nu_\tau mass. In particular, we point out that a large range of Μτ\nu_\tau masses are forbidden by the cosmological constraints on mΜτm_{\nu_\tau} in combination with the present upper limits on these processes.Comment: UMDHEP 94-30, 14 pages, TeX file, (some new references added

    MeV neutrinos in double beta decay

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    The effect of Majorana neutrinos in the MeV mass range on the double beta decay of various isotopes is studied on pure phenomenological arguments. By using only experimental half life data, limits on the mixing parameter Ueh2U_{eh}^2 of the order 10−7^{-7} can be derived. Also the possible achievements of upcoming experiments and some consequences are outlined.Comment: 7 pages, 6 uudecoded EPS-figure

    Effects of e−e+Îœee^- e^+ \nu_e Decays of Tau Neutrinos Near A Supernova

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    We revisit the constraints implied by SN 1987 A observations on the decay rate of a multi-MeV Μτ\nu_\tau decaying into the visible channel Μτ→e+e−Μe\nu_\tau \rightarrow e^+ e^- \nu_e, if its lifetime is more than 10 {\it sec.}. We discuss its implication for the minimal left-right symmetric model with see-saw mechanism for neutrino masses. We also speculate on the possible formation of a ``giant Capacitor" in intergalactic space due to the decay of "neutronization" Μτ\nu_\tau's and spin allignment possibility in the supernova.Comment: 29 Pages, Tex file, UMDHEP 94-4

    Reconciling Supersymmetry and Left-Right Symmetry

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    We construct the minimal supersymmetric left-right theory and show that at the renormalizable level it requires the existence of an intermediate B−LB-L breaking scale. The subsequent symmetry breaking down to MSSM automatically preserves R-symmetry. Furthermore, unlike in the nonsupersymmetric version of the theory, the see-saw mechanism takes its canonical form. The theory predicts the existence of a triplet of Higgs scalars much lighter than the B−LB-L breaking scale.Comment: 4 pages, revtex, no figure

    Spontaneous Parity Violation in SUSY Strong Gauge Theory

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    We suggest simple models of spontaneous parity violation in supersymmetric strong gauge theory. We focus on left-right symmetric model and investigate vacuum with spontaneous parity violation. Non-perturbative effects are calculable in supersymmetric gauge theory, and we suggest two new models. The first model shows confinement, and the second model has a dual description of the theory. The left-right symmetry breaking and electroweak symmetry breaking are simultaneously occurred with the suitable energy scale hierarchy. The second model also induces spontaneous supersymmetry breaking.Comment: 14 page
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