1,233 research outputs found
Quark Mass Hierarchies, Flavor Mixing and Maximal CP-Violation
Flavor mixing and the quark mass spectrum are intimately related. In view of
the observed strong hierarchy of the quark and lepton masses and of the flavor
mixing angles it is argued that the description of flavor mixing must take this
into account. One particular interesting way to describe the flavor mixing
emerges, which is particularly suited for models of quark mass matrices based
on flavor symmetries. We conclude that the unitarity triangle important for
physics should be close to or identical to a rectangular triangle.
violation is maximal in this sense.Comment: 21 latex page
Hierarchy and Anarchy in Quark Mass Matrices, or Can Hierarchy Tolerate Anarchy?
The consequences of adding random perturbations (anarchy) to a baseline
hierarchical model of quark masses and mixings are explored. Even small
perturbations of the order of 5% of the smallest non-zero element can already
give deviations significantly affecting parameters of the
Cabibbo-Kobayashi-Maskawa (CKM) matrix, so any process generating the anarchy
should in general be limited to this order of magnitude. The regularities of
quark masses and mixings thus appear to be far from a generic feature of
randomness in the mass matrices, and more likely indicate an underlying order.Comment: 11 pages, LaTeX, 3 figures, to be submitted to Phys. Lett. B.
Abstract and Introduction changed to better reflect conclusion
Implications of the KamLAND Measurement on the Lepton Flavor Mixing Matrix and the Neutrino Mass Matrix
We explore some important implications of the KamLAND measurment on the
lepton flavor mixing matrix and the neutrino mass matrix . The
model-independent constraints on nine matrix elements of are obtained to a
reasonable degree of accuracy. We find that nine two-zero textures of are
compatible with current experimental data, but two of them are only marginally
allowed. Instructive predictions are given for the absolute neutrino masses,
Majorana phases of CP violation, effective masses of the tritium beta decay and
neutrinoless double beta decay.Comment: RevTex 15 pages (4 PS figures included
and Expansion of the Weak Mixing Matrix
We perform a and expansion of the Cabibbo-Kobayashi- Maskawa
mixing matrix. Data suggest that the dominant parts of the Yukawa couplings are
factorizable into sets of numbers , , and ,
associated, respectively, with the left-handed doublets, the right-handed up
singlets, and the right- handed down singlets. The first order expansion is
consistent with Wolfenstein parameterization, which is an expansion in to third order. The mixing matrix elements in the present approach
are partitioned into factors determined by the relative orientations of , , and and the dynamics provided by the subdominant
mass matrices. A short discussion is given of some experimental support and a
generalized Fritzsch model is used to contrast our approach.Comment: A set of references has been added to ealier related wor
Composite Weak Bosons, Leptons and Quarks
The weak bosons consist of two fermions, bound by a new confining gauge
force. The mass scale of this new interaction is determined. At energies below
0.5 TeV the standard electroweak theory is valid. A neutral isoscalar weak
boson X must exist - its mass is less than 1 TeV. It will decay mainly into
quark and lepton pairs and into two or three weak bosons. Above the mass of 1
TeV one finds excitations of the weak bosons, which mainly decay into pairs of
weak bosons. Leptons and quarks consist of a fermion and a scalar. Pairs of
leptons and pairs of quarks form resonances at very high energy.Comment: 11 pages, no figure
A Search for the Fourth SM Family Fermions and E_6 Quarks at Colliders
The potential of colliders to investigate the fourth SM
family fermions predicted by flavour democracy has been analyzed. It is shown
that muon colliders are advantageous for both pair production of fourth family
fermions and resonance production of fourth family quarkonia. Also isosinglet
quarks production at colliders has been investigated.Comment: 9 pages, 5 table
Hierarchy and Up-Down Parallelism of Quark Mass Matrices
In view of the quark mass hierarchy and in the assumption of the up-down
parallelism, we derive two phenomenologically-favored patterns of Hermitian
quark mass matrices from the quark flavor mixing matrix. We compare one of them
with two existing {\it Anstze} proposed by Rosner and Worah and by
Roberts {\it et al}, and find that only the latter is consistent with the
present experimental data.Comment: RevTex 9 pages. Accepted for publication in Phys. Rev.
Nearly Bi-Maximal Neutrino Mixing, Muon g-2 Anomaly and Lepton-Flavor-Violating Processes
We interpret the newly observed muon g-2 anomaly in the framework of a
leptonic Higgs doublet model with nearly degenerate neutrino masses and nearly
bi-maximal neutrino mixing. Useful constraints are obtained on the rates of
lepton-flavor-violating rare decays ,
and as well as the - conversion ratio .
We find that , and
depend crucially on possible non-zero but samll values of the
neutrino mixing matrix element , and they are also sensitive to the
Dirac-type CP-violating phase. In particular, we show that , and are approximately in the ratio if is much larger than , and in the
ratio if is much lower than , where and are the corresponding mass-squared
differences of atmospheric and solar neutrino oscillations.Comment: LaTex 6 pages (2 PS figures). Phys. Rev. D (in printing
Democratic Neutrino Mixing and Radiative Corrections
The renormalization effect on a specific ansatz of lepton mass matrices,
arising naturally from the breaking of flavor democracy for charged leptons and
that of mass degeneracy for light neutrinos, is studied from a superhigh energy
scale M_0 \sim 10^{13} GeV to the electroweak scale in the framework of the
minimal supersymmetric standard model. We find that the democratic neutrino
mixing pattern obtained from this ansatz may in general be instable against
radiative corrections. With the help of similar flavor symmetries we prescribe
a slightly different scheme of lepton mass matrices at the scale M_0, from
which the democratic mixing pattern of lepton flavors can be achieved, after
radiative corrections, at the experimentally accessible scales.Comment: RevTex 8 pages. Phys. Rev. D (in printing
The anomalous magnetic moment of the muon and radiative lepton decays
The leptons are viewed as composite objects, exhibiting anomalous magnetic
moments and anomalous flavor-changing transition moments. The decay is expected to occur with a branching ratio of the same order as the
present experimental limit.Comment: 5 page
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