2,900 research outputs found
Aspects of Neutrino Mass Matrices
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
Flavor symmetry () where is the binary tetrahedral
group predicts for neutrino mixing angles and, with one phenomenological input, provides
upper and lower bounds on both and . The predictions
arise from the deviation of the Cabibbo angle from its
lowest-order value and from the
mechanism which relates mixing of neutrinos to
mixing of quarks.Comment: Typos. Reference adde
Conformality and Gauge Coupling Unification
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 in conformal gauge
theories with three chiral families.Comment: 8 pages LaTe
Analysis of Quark Mixing Using Binary Tetrahedral Flavor Symmetry
Using the binary tetrahedral group , the three angles and phase of the
quark CKM mixing matrix are pursued by symmetry-breaking which involves
-doublet VEVs and the Chen-Mahanthappa CP-violation mechanism. The
NMRTM, 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
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
In the aspon model solution of the strong problem, there is a gauged
symmetry, spontaneously broken by the same vacuum expectation value
which breaks , whose massive gauge boson provides an additional mechanism
of weak violation. We calculate the asymmetries in decays for the
aspon model and show that they are typically smaller than those predicted from
the standard model. A linear relation between the asymmetries of different
decay processes is obtained.Comment: REVTEX, 9 pages, IFP-486-UNC, NSF-PT-94-1, and UDHEP-01-9
Entropic Inflation
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
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
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
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
- …