994,348 research outputs found
Theoretical Expectations for Rare and Forbidden Tau Decays
Given the experimental evidence for oscillations, the
existence of lepton flavor violation in decays is a theoretical
certainty. In this brief review, I consider the connection between models of
neutrino mass and the expected observability of some decays.Comment: Talk at TAU 02 (Santa Cruz, CA
Dark Scalar Doublets and Neutrino Tribimaximal Mixing from A_4 Symmetry
In the context of A_4 symmetry, neutrino tribimaximal mixing is achieved
through the breaking of A_4 to Z_3 (Z_2) in the charged-lepton (neutrino)
sector respectively. The implied vacuum misalignment of the (1,1,1) and (1,0,0)
directions in A_4 space is a difficult technical problem, and cannot be treated
without many auxiliary fields and symmetries (and perhaps extra dimensions). It
is pointed out here that an alternative scenario exists with A_4 alone and no
redundant fields, if neutrino masses are "scotogenic", i.e. radiatively induced
by dark scalar doublets as recently proposed.Comment: 8 pages, 2 figures, 1 reference and 1 paragraph adde
Verifiable Origin of Neutrino Mass at TeV Scale
The physics responsible for neutrino mass may reside at or below the TeV
energy scale. The neutrino mass matrix in the
basis may then be deduced from future high-energy accelerator experiments. The
newly observed excess in the muon anomalous magnetic moment may also be
related.Comment: 9 pages, 1 figure, talk at TAUP 200
Quark Mass Matrices from a Softly Broken U(1) Symmetry
Assigning U(1) charges to the quarks of the standard model, and allowing one
extra scalar doublet with m^2 > 0, the correct pattern of the up and down quark
mass matrices is obtained, together with their charged-current mixing matrix.Comment: 10 pages, no figur
Discrete Symmetry and CP Phase of the Quark Mixing Matrix
A simple specific pattern of the two 3 X 3 quark mass matrices is proposed,
resulting in a prediction of the CP phase of the charged-current mixing matrix
V_CKM, i.e. sin 2 phi_1 (beta) = 0.733, which is in remarkable agreement with
data, i.e. sin 2 phi_1 = 0.728 +/- 0.056 +/- 0.023 from Belle and sin 2 beta =
0.722 +/- 0.040 +/- 0.023 from Babar. This pattern can be maintained by a
discrete family symmetry, an example of which is D_7, the symmetry group of the
heptagon.Comment: 9 pages, no figur
Discovery of Newly Formed Broad Absorption Lines in a Radio-Loud Quasar
We report a serendipitous discovery of broad absorption lines that were newly
formed in the spectrum of the high-redshift, luminous radio-loud quasar TEX
1726 + 344, in a time interval of only 12 years. This is the first quasar
showing a transition from narrow absorption lines to broad absorption lines. It
also becomes one of the few radio-loud broad absorption line quasars. The gas
cloud responsible for these broad absorption lines is derived to have
parameters coinciding with those of the remnant of a tidally disrupted star.Comment: 6 pages, 1 figure, accepted for publication as a Letter in Mon. Not.
R. Astron. So
Obtaining the Neutrino Mixing Matrix with the Tetrahedral Group
We discuss various "minimalist'' schemes to derive the neutrino mixing matrix
using the tetrahedral group $A_{4}.
Near Tribimaximal Neutrino Mixing with Delta(27) Symmetry
The discrete subgroup Delta(27) of SU(3) has the interesting multiplication
rule 3 X 3 = bar{3} + bar{3} + bar{3}, which is used to obtain near
tribimaximal neutrino mixing. Using present neutrino oscillation data as input,
this model predicts that the effective mass m_{ee} measured in neutrinoless
double beta decay will be 0.14 eV.Comment: 6 pages, no figur
Phase Transitions for Belousov-Zhabotinsky Reactions
The main objective of this article is to study the dynamic phase transitions
associated with the spatial-temporal oscillations of the BZ reactions, given by
Field, Koros and Noyes, also referred as the Oregonator. Two criteria are
derived to determine 1) existence of either multiple equilibria or
spatiotemporal oscillations, and 2) the types of transitions. These criteria
gives a complete characterization of the dynamic transitions of the BZ systems
from the homogeneous states. The analysis is carried out using a dynamic
transition theory developed recently by the authors, which has been
successfully applied to a number of problems in science
A catalog of Kazarian galaxies
The entire Kazarian galaxies (KG) catalog is presented which combines
extensive new measurements of their optical parameters with a literature and
database search. The measurements were made using images extracted from the
STScI Digitized Sky Survey (DSS) of Jpg(blue), Fpg(red) and Ipg(NIR) band
photographic sky survey plates obtained by the Palomar and UK Schmidt
telescopes. We provide accurate coordinates, morphological type, spectral and
activity classes, blue apparent diameters, axial ratios, position angles, red,
blue and NIR apparent magnitudes, as well as counts of neighboring objects in a
circle of radius 50 kpc from centers of KG. Special attention was paid to the
individual descriptions of the galaxies in the original Kazarian lists, which
clarified many cases of misidentifications of the objects, particularly among
interacting systems. The total number of individual Kazarian objects in the
database is now 706. We also include the redshifts which are now available for
404 galaxies and the 2MASS infrared magnitudes for 598 KG. The database also
includes extensive notes, which summarize information about the membership of
KG in different systems of galaxies, and about revised activity classes and
redshifts. An atlas of several interesting subclasses of KG is also presented.Comment: 15 pages, 5 figures, 1 table, Accepted in Astrophysics, Vol. 53, No.
1, 2010 (English translation of Astrofizika
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