11,288 research outputs found
Yukawaon Approach to the Sumino Relation for Charged Lepton Masses
On the basis of a supersymmetric yukawaon model, Sumino's relation for
charged lepton masses is re-derived. A relation between values of and
is investigated without using a relation . Predicted
value of is compared with the observed value of ,
and it is concluded that the value is of the
order of or less.Comment: 14 pages, 3 figures, version accepted by PL
Lepton Family Symmetry and Possible Application to the Koide Mass Formula
A finite group generated by four Z_3 transformations is applied to lepton
families in a supersymmetric model, resulting in the charged-lepton masses m_i
being proportional to v_i^2, where v_i are three vacuum expectation values.
This may be relevant in obtaining the Koide formula m_e + m_mu + m_tau =
(2/3)(sqrt{m_e} + sqrt{m_mu} + sqrt(m_tau})^2.Comment: 10 pages, no figur
Charged Lepton Mass Formula -- Development and Prospect --
The recent devolopment on the charged lepton mass forumula
m_e+m_{\mu}+m_{\tau}={2/3}(\sqrt{m_e}+\sqrt{m_\mu}+\sqrt{m_{\tau}})^2 is
reviewed. An S_3 or A_4 model will be promising for the mass relation.Comment: Latex, 11 pages, no figure, Talk at Internationa Workshop on Neutrino
Masses and Mixing, at Shizuoka, Japan, December, 17-19, 200
Family Gauge Bosons with an Inverted Mass Hierarchy
A model that gives family gauge bosons with an inverted mass hierarchy is
proposed, stimulated by Sumino's cancellation mechanism for the QED radiative
correction to the charged lepton masses. The Sumino mechanism cannot
straightforwardly be applied to SUSY models because of the non-renormalization
theorem. In this paper, an alternative model which is applicable to a SUSY
model is proposed. It is essential that family gauge boson masses in
this model is given by an inverted mass hierarchy , in contrast to in the
original Sumino model. Phenomenological meaning of the model is also
nvestigated. In particular, we notice a deviation from the -
universality in the tau decays.Comment: 13 pages, 1 fugure, added discussion on the neutrino sector, version
accepted by Phys.Lett.
Permutation Symmetry S_3 and VEV Structure of Flavor-Triplet Higgs Scalars
A model with flavor-triplet Higgs scalars \phi_i (i=1,2,3)is investigated
under a permutation symmetry S_3 and its symmetry breaking. A possible S_3
breaking form of the Higgs potential whose vacuum expectation values v_i=<
\phi_i> satisfy a relation v_1^2 +v_2^2 +v_3^2 ={2/3}(v_1 +v_2 +v_3)^2 is
investigated, because if we suppose a seesaw-like mass matrix model M_e = m
M^{-1} m with m_{ij} \propto \delta_{ij} v_i and M_{ij} \propto \delta_{ij},
such a model can lead to the well-known charged lepton mass relation m_e +m_\mu
+m_\tau = {2/3} (\sqrt{m_e}+\sqrt{m_\mu} +\sqrt{m_\tau})^2.Comment: 7 pages, 1 figure, final version to appear in PR
S_4 Flavor Symmetry Embedded into SU(3) and Lepton Masses and Mixing
Based on an assumption that an S_4 flavor symmetry is embedded into SU(3), a
lepton mass matrix model is investigated. A Frogatt-Nielsen type model is
assumed, and the flavor structures of the masses and mixing are caused by VEVs
of SU(2)_L-singlet scalars \phi_u and \phi_d which are nonets (8+1) of the
SU(3) flavor symmetry, and which are broken into 2+3+3' and 1 of S_4. If we
require the invariance under the transformation (\phi^{(8)},\phi^{(1)}) \to
(-\phi^{(8)},+\phi^{(1)}) for the superpotential of the nonet field
\phi^{(8+1)}, the model leads to a beautiful relation for the charged lepton
masses. The observed tribimaximal neutrino mixing is understood by assuming two
SU(3) singlet right-handed neutrinos \nu_R^{(\pm)} and an SU(3) triplet scalar
\chi.Comment: 12 pages, no figure, to appear on JHE
Seesaw Mass Matrix Model of Quarks and Leptons with Flavor-Triplet Higgs Scalars
In a seesaw mass matrix model M_f = m_L M_F^{-1} m_R^\dagger with a universal
structure of m_L \propto m_R, as the origin of m_L (m_R) for quarks and eptons,
flavor-triplet Higgs scalars whose vacuum expectation values v_i are
proportional to the square roots of the charged lepton masses m_{ei}, i.e. v_i
\propto \sqrt{m_{ei}}, are assumed. Then, it is investigated whether such a
model can explain the observed neutrino masses and mixings (and also quark
masses and mixings) or not.Comment: version accepted by EPJ
A Unified Description of Quark and Lepton Mass Matrices in a Universal Seesaw Model
In the democratic universal seesaw model, the mass matrices are given by
\bar{f}_L m_L F_R + \bar{F}_L m_R f_R + \bar{F}_L M_F F_R (f: quarks and
leptons; F: hypothetical heavy fermions), m_L and m_R are universal for up- and
down-fermions, and M_F has a structure ({\bf 1}+ b_f X) (b_f is a
flavour-dependent parameter, and X is a democratic matrix). The model can
successfully explain the quark masses and CKM mixing parameters in terms of the
charged lepton masses by adjusting only one parameter, b_f. However, so far,
the model has not been able to give the observed bimaximal mixing for the
neutrino sector. In the present paper, we consider that M_F in the quark
sectors are still "fully" democratic, while M_F in the lepton sectors are
partially democratic. Then, the revised model can reasonably give a nearly
bimaximal mixing without spoiling the previous success in the quark sectors.Comment: 7 pages, no figur
New Trends in the Zee Model
Recent trends in the Zee model are reviewed. Especially, the importance of a
serious constraint in the Zee model, sin^2 2\theta_{solar} =1.0, is pointed
out.Comment: 3 pages, Latex, Plenary talk given at NuFact'01 (held in Tukuba,
Japan, 24-30 May 2001), to appear in the Proceeding
A_4 Symmetry and Lepton Masses and Mixing
Stimulated by Ma's idea which explains the tribimaximal neutrino mixing by
assuming an A_4 flavor symmetry, a lepton mass matrix model is investigated. A
Frogatt-Nielsen type model is assumed, and the flavor structures of the masses
and mixing are caused by the VEVs of SU(2)_L-singlet scalars \phi_i^u and
\phi_i^d (i=1,2,3), which are assigned to {\bf 3} and ({\bf 1}, {\bf 1}',{\bf
1}'') of A_4, respectively.Comment: 13 pages including 1 table, errors in Sec.7 correcte
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