40,611 research outputs found

    Mass dimension one fermions from flag dipole spinors

    Full text link
    According to the Lounesto classification, there are six classes of spinors. The Dirac and Weyl spinors belong to the first three and the sixth classes respectively. The remaining fourth and fifth classes are known as the flag dipole and flag pole spinors respectively. In this letter, a mass dimension one fermionic field with flag dipole spinors as expansion coefficients is constructed. These spinors are shown to be related to Elko (flag pole spinors) by a matrix transformation. It shows that the flag dipole spinors are generalizations of Elko. To construct a Lorentz-covariant quantum field, an infinitesimal deformation is applied to the spinor dual. Subsequently, we show that the fermionic fields constructed from Elko and flag dipole spinors are physically equivalent.Comment: 10 page

    Penguin-induced Radiative Baryonic B Decays Revisited

    Full text link
    Weak radiative baryonic B decays Bˉ→B1Bˉ2γ\bar B\to B_1\bar B_2\gamma mediated by the electromagnetic penguin process b→sγb\to s\gamma are re-examined within the framework of the pole model. The meson pole contribution that has been neglected before is taken into account in this work. It is found that the intermediate K∗K^* contribution dominates in the Σpˉγ\Sigma\bar p\gamma mode and is comparable to the baryon pole effect in Λpˉγ\Lambda\bar p\gamma and ΞΛˉγ\Xi\bar\Lambda\gamma modes. The branching ratios for B−→ΛpˉγB^-\to\Lambda\bar p\gamma and B−→Ξ0Σˉ−γB^-\to\Xi^0\bar\Sigma^-\gamma are of order 2.6×10−62.6\times 10^{-6} and 6×10−76\times 10^{-7}, respectively. The threshold enhancement effect in the dibaryon mass spectrum is responsible by the meson pole diagram. We also study the angular distribution of the baryon in the dibaryon rest frame. The baryon pole diagrams imply that the antibaryon tends to emerge in the direction of the photon in the baryon-pair rest frame. The predicted angular asymmetry agrees with experiment for B−→ΛpˉγB^-\to\Lambda\bar p\gamma. Measurements of the correlation of the photon with the baryon allow us to discriminate between different models for describing the radiative baryonic B decays. For decays B→ΞΣˉγB\to\Xi\bar\Sigma\gamma, a large correlation of the photon to the Σˉ\bar\Sigma and a broad bump in the dibaryon mass spectrum are predicted.Comment: 10 pages, 4 figure

    Magnetic field creation by solar mass neutrino jets

    Full text link
    Parity violation and its effects for neutrinos in astrophysical contexts have been considered earlier in pioneering papers of Hawking and Vilenkin. But because even the largest magnetic moments predicted by physics beyond the Standard Model are some twelve orders of magnitude smaller than the Bohr magneton, their implications for magnetic field generation and neutrino oscillations are generally considered insignificant. Here we show that since in astrophysical scenarios a huge number of neutrinos may be emitted, the smallness of the magnetic moment, when coupled with parity violation, is compensated by the sheer number of neutrinos. The merger of neutron stars would leave behind a short pulse of electromagnetic synchrotron radiation even if the neutrino jet in the merger points away from the neutrino detectors. We show that the magnetic field can be as large as 10^6\,\mbox{Gauss} and comment on the possibility of direct detection. Observation of such a pulse would lend strong support for neutrino magnetic moments and resolve the missing neutrino problem in neutron star mergers.Comment: 5 pages, version accepted for publication in Europhysics Letters (EPL

    A QFT-induced phase in neutrino flavour oscillations

    Full text link
    In the extended Standard Model of particle physics, each neutrino mass eigenstate is predicted to have a tiny but non vanishing magnetic moment induced by quantum field theoretic corrections. These QFT-induced magnetic momenta depend linearly on masses of the underlying mass eigenstates with a proportionality constant 3eGF/(82Ï€2){3eG_{F}}/{(8\sqrt{2}\pi^{2})} . As a consequence when neutrinos are embedded in an environment containing magnetic fields the flavour oscillations get a contribution from the induced relative phases.Comment: 6 page
    • …
    corecore