The constraints on the number of neutrinos generations, g'1 coupling and Z?- Z′ mixing angle through the invisible width method, and in the framework of a U(1)B-L model are obtained. Based on the experimental val...The constraints on the number of neutrinos generations, g'1 coupling and Z?- Z′ mixing angle through the invisible width method, and in the framework of a U(1)B-L model are obtained. Based on the experimental value reported by the LEP for the rate , we obtained a bound on the g'1 coupling, . In addition, we derive 90% C.L. bounds on the Z?- Z′ mixing angle , improving the existing bounds by one order of magnitude.展开更多
In this work the neutral-current scattering cross-section for neutrinos on electrons is calculated assuming that a massive Dirac neutrino is characterized by a phenomenological parameters, a charge radius 2> and th...In this work the neutral-current scattering cross-section for neutrinos on electrons is calculated assuming that a massive Dirac neutrino is characterized by a phenomenological parameters, a charge radius 2> and the right-handed currents are present in the framework of a Left-Right symmetric model (LR). Using the CHARM II result for the charge radius of the muon-neutrino |2>|<6.0×10-33cm2, we place a bound on -7.9×10-33cm2≤2>LR≤7.9×10-33cm2. We discuss the relationship between the electron neutral couplings gVeV and gVeA and the LR model parameters. We also estimate a bound on the heavy massive neutral vector boson mass MZR>650GeV of the LR model. These results have never been reported in the literature before and could have practical or theoretical interest, such as in the case of the neutrinos produced in core-collapse supernova explosions, that is to say, right-handed Dirac neutrinos emission from supernova core vLe-→vRe-.展开更多
文摘The constraints on the number of neutrinos generations, g'1 coupling and Z?- Z′ mixing angle through the invisible width method, and in the framework of a U(1)B-L model are obtained. Based on the experimental value reported by the LEP for the rate , we obtained a bound on the g'1 coupling, . In addition, we derive 90% C.L. bounds on the Z?- Z′ mixing angle , improving the existing bounds by one order of magnitude.
文摘In this work the neutral-current scattering cross-section for neutrinos on electrons is calculated assuming that a massive Dirac neutrino is characterized by a phenomenological parameters, a charge radius 2> and the right-handed currents are present in the framework of a Left-Right symmetric model (LR). Using the CHARM II result for the charge radius of the muon-neutrino |2>|<6.0×10-33cm2, we place a bound on -7.9×10-33cm2≤2>LR≤7.9×10-33cm2. We discuss the relationship between the electron neutral couplings gVeV and gVeA and the LR model parameters. We also estimate a bound on the heavy massive neutral vector boson mass MZR>650GeV of the LR model. These results have never been reported in the literature before and could have practical or theoretical interest, such as in the case of the neutrinos produced in core-collapse supernova explosions, that is to say, right-handed Dirac neutrinos emission from supernova core vLe-→vRe-.