5,398 research outputs found
Leptonic CP Violation and Wolfenstein Parametrization for Lepton Mixing
We investigate a general structure of lepton mixing matrix resulting from the
SU(3) gauge family model with an appropriate vacuum structure of SU(3)
symmetry breaking. It is shown that the lepton mixing matrix can be
parametrized by using the Wolfenstein parametrization method to characterize
its deviation from the tri-bimaximal mixing. A general analysis for the allowed
leptonic CP-violating phase and the leptonic Wolfenstein parameters
, , is carried out based on the observed lepton mixing
angles. We demonstrate how the leptonic CP violation correlates to the leptonic
Wolfenstein parameters. It is found that the phase is strongly
constrained and only a large or nearly maximal leptonic CP-violating phase
is favorable when . In
particular, when taking to be the Cabbibo angle \gl_e\simeq
\lambda \simeq 0.225, a sensible result for leptonic Wolfenstein parameters
and CP violation is obtained with , , \delta_{e}\sim
101.76\;^o, which is compatible with the one in quark sector. An interesting
correlation between leptons and quarks is observed, which indicates a possible
common origin of masses and mixing for the charged-leptons and quarks.Comment: 18 pages, 5 figures, sources of CP-violating phases are clarified,
references adde
Positive co-degree Tur\'an number for and
The \emph{minimum positive co-degree} of a non-empty
-graph is the maximum such that if is an -set contained
in a hyperedge of , then is contained in at least hyperedges of .
For any -graph , the \emph{positive degree Tur\'an number}
is defined as the maximum value of
over all -vertex -free non-empty -graphs . In
this paper, we determine the positive degree Tur\'an number for and
.Comment: 8 page
Gauge Family Model and New Symmetry Breaking Scale From FCNC Processes
Based on the gauge family symmetry model which was proposed to
explain the observed mass and mixing pattern of neutrinos, we investigate the
symmetry breaking, the mixing pattern in quark and lepton sectors, and the
contribution of the new gauge bosons to some flavour changing neutral currents
(FCNC) processes at low energy. With the current data of the mass differences
in the neutral pseudo-scalar systems, we find that the
symmetry breaking scale can be as low as 300TeV and the mass of the
lightest gauge boson be about TeV. Other FCNC processes, such as the
lepton flavour number violation process
and the semi-leptonic rare decay , contain
contributions via the new gauge bosons exchanging. With the constrains got from
system, we estimate that the contribution of the new physics is
around , far below the current experimental bounds.Comment: 3figure
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