115 research outputs found
S4 Flavor Model of Quarks and Leptons
We present an flavor model to unify quarks and leptons in the framework
of the SU(5) GUT. Three generations of -plets in SU(5) are assigned
of while the first and the second generations of 10-plets in SU(5)
are assigned to be 2 of , and the third generation of 10-plet is to be
of . Right-handed neutrinos are also assigned 2 for the first and
second generations and for the third generation, respectively. Taking
vacuum alignments of relevant gauge singlet scalars, we predict the quark
mixing as well as the tri-bimaximal mixing of neutrino flavors. Especially, the
Cabbibo angle is predicted to be in the limit of the vacuum
alignment. We can improve the model to predict observed CKM mixing angles.Comment: 11 pages, talked at the 16th Yukawa International Seminar, Particle
Physics beyond the Standard Mode
Predicting CP violation in Deviation from Tri-bimaximal mixing of Neutrinos
We study the CP violation in the deviation from the tri-bimaximal mixing
(TBM) of neutrinos. We examine non-trivial relations among the mixing angles
and the CP violating Dirac phase in the typical four cases of the deviation
from the TBM. The first two cases are derived by the additional rotation of the
2-3 or 1-3 generations of neutrinos in the TBM basis. The other two cases are
given by the additional rotation of the 1-3 or 1-2 generations of charged
leptons with the TBM neutrinos. These four cases predict different relations
among three mixing angles and the CP violating Dirac phase. The rotation of the
2-3 generations of neutrinos in the TBM basis predicts , and the CP violating Dirac phase to be
for NH () depending on . The rotation of the 1-3 generations of neutrinos in the TBM
basis gives . The CP violating Dirac phase is not
constrained by the input of the present experimental data. For the case of the
1-3 and 1-2 rotations of charged leptons in the TBM basis, the CP violating
Dirac phase is predicted in depending on for both NH and IH cases. We also discuss the specific case
that is related with the Cabibbo angle such as
, in which the maximal CP violation is
preferred. The CP violating Dirac phase can distinguish the lepton flavor
mixing patterns at T2K and NOA experiments in the future.Comment: 18 pages, 22 figures, figures are changed, discussions are adde
Towards the minimal seesaw model via CP violation of neutrinos
We study the minimal seesaw model, where two right-handed Majorana neutrinos
are introduced, focusing on the CP violating phase. In addition, we take the
trimaximal mixing pattern for the neutrino flavor where the charged lepton mass
matrix is diagonal. Thanks to this symmetric framework, the Dirac
neutrino mass matrix is given in terms of a few parameters. Numerical studies
reveal that the observation of the CP violating phase can determine the flavor
structure of the Dirac neutrino mass matrix in the minimal seesaw model. In
particular, new minimal Dirac neutrino mass matrices are proposed in the case
of , which is derived by the additional 2-3 family mixing to the
tri-bimaximal mixing basis in the normal hierarchy of neutrino masses. Our
analyses include the Littlest seesaw model by King {\it et al.}, which is one
of the specific one in our results. Furthermore, it is remarked that our
Dirac neutrino mass matrix is reproduced by introducing gauge
singlet flavons with the specific alignments of the VEV's. These alignments
suggest the residual symmetry of group.Comment: 27 pages, 27 figures, final versio
Neutrino CP violation and sign of baryon asymmetry in the minimal seesaw model
We discuss the correlation between the CP violating Dirac phase of the lepton
mixing matrix and the cosmological baryon asymmetry based on the leptogenesis
in the minimal seesaw model with two right-handed Majorana neutrinos and the
trimaximal mixing for neutrino flavors. The sign of the CP violating Dirac
phase at low energy is fixed by the observed cosmological baryon asymmetry
since there is only one phase parameter in the model. According to the recent
T2K and NOA data of the CP violation, the Dirac neutrino mass matrix of
our model is fixed only for the normal hierarchy of neutrino masses.Comment: 19 pages, 4 figures, 1 table. 1 reference is added in this version.
arXiv admin note: text overlap with arXiv:1709.0213
Searching for the squark flavor mixing in CP violations of Bs -> K+ K- and K0bar K0 decays
We study CP violations in the B_s-> K+K- and Bs->K0K0 decays in order to find
the contribution of the supersymmetry, which comes from the gluino-squark
mediated flavor changing current. We obtain the allowed region of the squark
flavor mixing parameters by putting the experimental data, the mass difference
Delta M_Bs, the CP violating phase phi_s in Bs to J/psi phi decay and the b to
s gamma branching ratio. In addition to these data, we take into account the
constraint from the asymmetry of B0->K+pi because the Bs->K+K- decay is related
with the B0->K+pi- decay by replacing the spectator s with d. Under these
constraints, we predict the magnitudes of the CP violation in the Bs->K+K- and
Bs->K0K0 decays. The predicted region of the CP violation C_{K+K-} is strongly
cut from the direct CP violation of barB0 to K-pi+, therefore, the deviation
from the SM prediction of C_{K+K-} is not found. On the other hand, the CP
violation S_{K+K-} is possibly deviated from the SM prediction considerably, in
the region of 0.1- 0.5. Since the standard model predictions of C_{K0bar K0}
and S_{K0bar K0} are very small, the squark contribution can be detectable in
C_{K0bar K0} and S_{K0bar K0}. These magnitudes are expected in the region
C_{K0bar K0}=-0.06-0.06 and S_{K0bar K0}=-0.5-0.3. More precise data of these
CP violations provide us a crucial test for the gluino-squark mediated flavor
changing current.Comment: 20 pages, 10 figures, discussions added, references added. arXiv
admin note: substantial text overlap with arXiv:1307.037
Like-sign dimuon asymmetry of B0 meson and LFV in SU(5) SUSY GUT with S4 flavor symmetry
The like-sign dimuon charge asymmetry of the meson, which was reported in
the D\O Collaboration, is studied in the SU(5) SUSY GUT model with
flavor symmetry. Additional CP violating effects from the squark sector are
discussed in mixing process. The predicted like-sign charge
asymmetry is in the 2 range of the combined result of D\O and CDF
measurements. Since the SUSY contributions in the quark sector affect to the
lepton sector because of the SU(5) GUT relation, two predictions are given in
the leptonic processes: (i) both and the electron
EDM are close to the present upper bound, (ii) the decay ratios of
decays, and , are related to each other
via the Cabibbo angle : {\rm BR}(\tau \to e\gamma)/{\rm BR}(\tau
\to \mu\gamma)\sime \lambda_c^2. These are testable at future experiments.Comment: 33 pages, 4 figures, a footnote and references are adde
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