2,900 research outputs found

    Aspects of Neutrino Mass Matrices

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    After an Introduction briefly describing the rise and fall of the three-zero texture of the Zee model, we discuss still-allowed two-zero textures for the Majorana three-neutrino mass matrix. Finally, a model with two right-handed neutrinos and two Dirac texture zeros is described (FGY model) which can relate CP violation in leptogenesis to CP violation in long-baseline neutrino oscillations.Comment: 9 pages latex. Talk at Coral Gables 2003. Added reference

    Predictions of Neutrino Mixing Angles in a T'Model

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    Flavor symmetry (T×Z2T^{'} \times Z_2) where TT^{'} is the binary tetrahedral group predicts for neutrino mixing angles θ13=2(π4θ23)\theta_{13} = \sqrt{2} (\frac{\pi}{4} - \theta_{23}) and, with one phenomenological input, provides upper and lower bounds on both θ13\theta_{13} and θ23\theta_{23}. The predictions arise from the deviation of the Cabibbo angle Θ12\Theta_{12} from its lowest-order value tan2Θ12=(2)/3\tan 2\Theta_{12} = (\sqrt{2})/3 and from the TT^{'} mechanism which relates mixing of (ντ,νμ,νe)(\nu_{\tau}, \nu_{\mu}, \nu_e) neutrinos to mixing of (s,d)(s, d) quarks.Comment: Typos. Reference adde

    Conformality and Gauge Coupling Unification

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    It has been recently proposed to embed the standard model in a conformal gauge theory to resolve the hierarchy problem, and to avoid assuming either grand unification or low-energy supersymmetry. By model building based on string-field duality we show how to maintain the successful prediction of an electroweak mixing angle with sin2θ0.231sin^2\theta \simeq 0.231 in conformal gauge theories with three chiral families.Comment: 8 pages LaTe

    Analysis of Quark Mixing Using Binary Tetrahedral Flavor Symmetry

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    Using the binary tetrahedral group TT^{'}, the three angles and phase of the quark CKM mixing matrix are pursued by symmetry-breaking which involves TT^{'}-doublet VEVs and the Chen-Mahanthappa CP-violation mechanism. The NMRT^{'}M, Next-to-Minimal-Renormalizable -T^{'}-Model is described, and its one parameter comparison to experimental data is explored.Comment: 14 pages latex. Two .eps figures include

    Virtual bilepton effects in polarized Moller scattering

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    We investigate the indirect effects of heavy vector bileptons being exchanged in polarized Moller scattering, at the next generation of linear colliders. Considering both longitudinal and transverse beam polarization, and accounting for initial-state radiation, beamstrahlung and beam energy spread, we discuss how angular distributions and asymmetries can be used to detect clear signals of virtual bileptons, and the possibility of distinguishing theoretical models that incorporate these exotic particles. We then estimate 95% C.L. bounds on the mass of these vector bileptons and on their couplings to electrons.Comment: 19 pages, 10 figure

    Outcome from Spontaneous CP Violation for B Decays

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    In the aspon model solution of the strong CPCP problem, there is a gauged U(1)U(1) symmetry, spontaneously broken by the same vacuum expectation value which breaks CPCP, whose massive gauge boson provides an additional mechanism of weak CPCP violation. We calculate the CPCP asymmetries in BB decays for the aspon model and show that they are typically smaller than those predicted from the standard model. A linear relation between the CPCP asymmetries of different decay processes is obtained.Comment: REVTEX, 9 pages, IFP-486-UNC, NSF-PT-94-1, and UDHEP-01-9

    Entropic Inflation

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    One of the major pillars of modern cosmology theory is a period of accelerating expansion in the early universe. This accelerating expansion, or inflation, must be sustained for at least 30 e--foldings. One mechanism used to drive the acceleration is the addition of a new energy field, called the Inflaton; often this is a scalar field. We propose an alternative mechanism which, like our approach to explain the late-time accelerating universe, uses the entropy and temperature intrinsic to information holographically stored on a surface enclosing the observed space. The acceleration is due in both cases to an emergent entropic force, naturally arising from the information storage on the horizon.Comment: 12 pages; version to appear in IJMP

    Private Well Owners Pay Price as MTBE Contamination Exposes the Lack of Groundwater Protection in Federal and New York Law

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    Since 1992 Methyl Tertiary Butyl Ether (MTBE) has been routinely added to gasoline in response to the Clean Air Act amendments of 1990, in an attempt to reduce carbon dioxide emissions. MTBE production has become a multi-billion dollar industry, as it now makes up 85% of the reformulated gasoline market. Although the health risks posed by the seemingly omnipresent chemical are still being debated, MTBE is highly soluble in water and when introduced to groundwater, it is devilishly difficult to remove. This article explores the potential federal and New York State laws that could provide a legal remedy for MTBE contamination of a private water well. Do citizens with private water wells have recourse when MTBE fouls the water under their land? Are there laws that protect groundwater as a natural resource from such pervasive chemicals as MTBE? Ultimately, this article concludes that federal and New York State laws do not provide adequate opportunities for a citizen to be compensated for MTBE contamination of groundwater. This legal gap represents the failure of state and federal law to protect groundwater as a natural resource

    The Cabibbo Angle in a Supersymmetric D14 Model

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    We construct a supersymmetric model with the flavor symmetry D14 in which the CKM matrix element |V_{ud}| can take the value |V_{ud}| =cos (pi/14) = 0.97493 implying that the Cabibbo angle theta_C is sin (theta_C) = |V_{us}| = sin (pi/14) = 0.2225. These values are very close to those observed in experiments. The value of |V_{ud}| (theta_C) is based on the fact that different Z2 subgroups of D14 are conserved in the up and down quark sector. In order to achieve this, D14 is accompanied by a Z3 symmetry. The spontaneous breaking of D14 is induced by flavons, which are scalar gauge singlets. The quark mass hierarchy is partly due to the flavor group D14 and partly due to a Froggatt-Nielsen symmetry U(1)_{FN} under which only the right-handed quarks transform. The model is completely natural in the sense that the hierarchies among the quark masses and mixing angles are generated with the help of symmetries. The issue of the vacuum alignment of the flavons is solved up to a small number of degeneracies, leaving four different possible values for |V_{ud}|. Out of these, only one of them leads to a phenomenological viable model. A study of the Z2 subgroup breaking terms shows that the results achieved in the symmetry limit are only slightly perturbed. At the same time they allow |V_{ud}| (theta_C) to be well inside the small experimental error bars.Comment: 1+24 page

    Quark masses without Yukawa hierarchies

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    A model based on the local gauge group SU(3)_c x SU(3)_L x U(1)_X without particles with exotic electric charges is shown to be able to provide the quark mass spectrum and their mixing, by means of universal see-saw mechanisms, avoiding a hierarchy in the Yukawa coupling constants.Comment: 7 pages, 1 eps figure. Published in Europhysics Letter
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