1997
To be published in Phys. Rev. D57, No.7 (1998)
Updated Estimate of Running Quark Masses
Hideo Fusaoka and Yoshio Koide
Stimulated by recent development of the calculation methods of
the running quark masses m_q(\mu) and renewal of the input data,
for the purpose of making a standard table of m_q(\mu) for
convenience of particle physicists, the values of m_q(\mu) at
various energy scales \mu (\mu = 1 GeV, \mu = m_c, \mu=m_b,
\mu=m_t and so on), especially at \mu = m_Z, are systematically
evaluated by using the mass renormalization equations and by
taking into consideration a matching condition at the quark threshold.
To be published in Phys. Rev. D, (1998)
Neutrino Masses and Mixings in a Universal Seesaw Mass Matrix Model
Neutrino masses and mixings are investigated on the basis of a universal
seesaw mass matrix model, in which quark (except for top) and charged
lepton mass matrices M_f and neutrino mass matrix M_\nu are given by
M_f \simeq m_L M_F^{-1} m_R and M_\nu \simeq m_L M_F^{-1} m_L^T (F=N),
respectively. For a simple model which can successfully describe quark
masses and mixings, we find that the observed neutrino data (except for
the solar neutrino data) are favor to the intermediate mass scales
O(m_R) = 10^{11} GeV and O(M_F)= 10^{13} GeV together with O(m_L)= 10^2
GeV. In spite of the largesse of O(m_R), the observed top quark mass
can be consistently understood from the would-be seesaw mass matrix
with these mass scales.
Phys. Rev. D56, 2656 (1997)
Abnormal Structure of Fermion Mixings in a Seesaw Quark Mass Matrix Model
It is pointed out that in a seesaw quark mass matrix model which
yields a singular enhancement of the top-quark mass, the right-handed
fermion-mixing matrix U_R^u for the up-quark sector has a peculiar
structure in contrast to the left-handed one U_L^u. As an example of
the explicit structures of U_L^u and U_R^u, a case in which the heavy
fermion mass matrix M_F is given by a form [(unit matrix)+(rank-one
matrix)] is investigated. As a consequence, one finds observable
signatures at projected high energy accelerators like the production
of a fourth heavy quark family.
To be published in the Proceedings of MMQL97
Updated Running Quark Mass Values
Hideo Fusaoka and Yoshio Koide
The running quark masses m_q(mu) at various energy scales
mu (mu= 1 GeV, mu=m_q, mu=m_Z and so on) are evaluated by
using the mass renormalization equations systematically.
Also, those at energy scales mu higher than mu=m_Z (from
mu=10^3 GeV to mu=10^{16} GeV) are evaluated by using the
evolution equations of Yukawa coupling constants for the
standard model with a single Higgs boson.
To be published in the Proceedings of MMQL97
Democratic Seesaw Mass Matrix Model and New Physics
A seesaw mass matrix model is reviewed as a unification model of quark
and lepton mass matrices. The model can understand why top-quark mass
m_t is so singularly enhanced compared with other quark masses, especially,
why m_t >> m_b in contrast to m_u = O(m_d), and why only top-quark mass
is of the order of the electroweak scale Lambda_W, i.e., m_t = O(Lambda_W).
The model predicts the fourth up-quark t' with a mass m_{t'}= O(m_{W_R}),
and an abnormal structure of the right-handed up-quark mixing matrix U_R^u.
Possible new physics is discussed.
Mod. Phys. Lett. A12, 2655 (1997)
NNI-Form Quark Mass Mass Matrix
Expressed by the Observable Quantities
It is pointed out that the phase convention of CKM matrix V
affects texture analysis of the quark mass matrices (M_u, M_d)
when we try to describe (M_u, M_d) by the observable quantities
(quark masses and CKM matrix parameters) only. This is
demonstrated for a case of the non-Hermitian Fritzsch-type mass
matrix (\widetilde{M}_u, \widetilde{M}_d), which is a general
expression of quark mass matrix (M_u, M_d) and is described by
twelve parameters. We find that we can always choose a phase
convention of V which yields \widetilde{M}_{u32} = 0,
so that the remaining ten physical parameters in (\widetilde{M}_u,
\widetilde{M}_d) can completely be expressed by the ten observable
quantities.