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arXiv:1512.08386 [hep-ph]
Quark and Lepton Mass Matrices Described by Charged Lepton Masses
Yoshio Koide and Hiroyuki Nishiura
Recently, we proposed a unified mass matrix model for quarks and leptons,
in which, mass ratios and mixings of
the quarks and neutrinos are described using only the
observed charged lepton mass values as family-number-dependent
parameters and only six family-number-independent free
parameters. In spite of quite few parameters,
the model gives remarkable agreement with observed data (i.e.
CKM mixing, PMNS mixing and mass ratios). Moreover, the model
gives very interesting predictions for leptonic $CP$ violation
parameter $\delta_{CP}^\ell \simeq -70^\circ \simeq \delta_{CP}^q$
and effective neutrino mass $\langle m\rangle\simeq 21$ meV.
The present paper gives a theoretical
framework of the model in details.
arXiv:1510.05370 [hep-ph]
Phys.Rev.D 92, 111301(R) 1-6 (2015)
DOI: 10.1103/PhysRevD.92.111301
Quark and Lepton Mass Matrix Model
with Only Six Family-Independent Parameters
Yoshio Koide and Hiroyuki Nishiura
We propose a unified mass matrix model for quarks and leptons,
in which sixteen observables of mass ratios and mixings of
the quarks and neutrinos are
described by using no family number-dependent parameters except
for the charged lepton masses
and only six family number-independent free parameters.
The model is constructed by extending the so-called ``Yukawaon"
model to a seesaw type model with the smallest number of
possible family number-independent free parameters.
As a result, once the six parameters is fixed by the quark mixing
and the mass ratios of quarks and neutrinos, no free parameters are
left in the lepton mixing matrix.
The results are in excellent agreement with the neutrino mixing data.
We predict $\delta_{CP}^\ell =-68^\circ$ for the leptonic $CP$
violating phase and $\langle m\rangle\simeq 21$ meV for the
effective Majorana neutrino mass.
arXiv:1507.07639 [hep-ph]
Published in Physical Review D, Vol.92, p.036009 (5 pages)
(2015) (American Physical Society)
DOI: 10.1103/PhysRevD.92.036009
Family Gauge Boson Mass Estimated from $K^+ \rightarrow \pi^+ \nu
It is emphasized that a rare decay $K^+ \rightarrow \pi^+ \nu \bar{\nu}$
becomes promising in a future search for a new particle, because the
theoretical treatment is well established and the value of the branching
ratio $Br(K^+ \rightarrow \pi^+ \nu \bar{\nu})$ is sensitive to a search
for a new particle with a TeV scale mass. As an example, according to
a U(3) family gauge boson model which predicts the lowest family gauge
boson with a few TeV mass $M_{11}$, the branching ratio
$Br(K^+ \rightarrow \pi^+ \nu \bar{\nu})$ is discussed. If we can
obtain, in future, a slightly lower value $Br^{obs} \sim 0.9 \times
10^{-10}$ compared with the present observed value
$Br^{obs}=(1.7\pm 1.1)\times 10^{-10}$, we can conclude
$M_{11} \sim$ a few TeV.
arXiv:1507.04987 [hep-ph]
Preprint No. KEK-TH-1851, KIAS-Q15004
Published in Physics Letters B Vol,750, pp.384-389
(2015) [Elsevier Pub]
DOI: 10.1016/j.physletb.2015.09.024
Family Gauge Boson Production at the LHC
Yoshio Koide, Masato Yamanaka, Hiroshi Yokoya
Family gauge boson production at the LHC is investigated
according to a $U(3)$ family gauge model with twisted family
number assignment. In the model we study, a family gauge boson
with the lowest mass, $A_1^{\ 1}$, interacts only with the first
generation leptons and the third generation quarks. (The family
numbers are assigned, for example, as $(e_1, e_2, e_3)= (e^-,
\mu^-, \tau^-)$ and $(d_1, d_2, d_3)=(b, d, s)$ [or
$(d_1, d_2, d_3)=(b, s, d)$]). In the model, the family gauge
coupling constant is fixed by relating to the electroweak gauge
coupling constant. Thus measurements of production cross
sections and branching ratios of $A_1^{\ 1}$ clearly confirm
or rule out the model. We calculate the cross sections of
inclusive $A_1^{\ 1}$ production and $b \bar{b} \, (t \bar{t})$
associated $A_1^{\ 1}$ production at $\sqrt{s} = 14~\text{TeV}$
and $100~\text{TeV}$. With the dielectron production cross
section, we discuss the determination of diagonalizing matrix
of quark mass matrix, $U_{u}$ and $U_{d}$, respectively.
arXiv:1507.00457 [hep-ph]
JPSJ Conf Proc. Vol.7, 010009 (2015).
http://dx.doi.org/10.7566/JPSCP.7.010009
Invited talk at CST-MISC Joint International Symposium
on Particle Physics from Spacetine Dynamics to Phenomenology
CST Hall, Nihon University, Tokyo, Japan, 15-16 Marc. 2014
Can Family Gauge Bosons Be Visible
by Terrestrial Experiments?
It is investigated whether observations of family gauge bosons
by terrestrial
experiments are possible or not.
We propose an extended version of
Sumino's family gauge boson model based on U(3) family symmetry.
Then, we can expect the lowest family gauge boson $A_1^1$
with $M \sim 4.3$ TeV.
arXiv:1503.04900 [hep-ph]
Phys.Rev. D, Vol.91, p.116002 (10 pages) (2015).
(American Physical Society)
DOI: 10.1103/PhysRevD.91.116002
Origin of Hierarchical Structures of Quark and Lepton Mass Matrices
Yoshio Koide and Hiroyuki Nishiura
It is shown that the so-called ``Yukawaon" model
can give a unified description of masses, mixing and $CP$ violation
parameters of
quarks and leptons without using any hierarchical (family number-dependent)
parameters besides the charged lepton masses.
Here, we have introduced a phase matrix
$P={\rm daig}(e^{i \phi_1}, e^{i \phi_2},
e^{i \phi_3})$ with the phase parameters
$(\phi_1, \phi_2, \phi_3)$ which are described in terms of family
number-independent parameters,
together with using only the charged lepton mass parameters
as the family number-dependent parameters.
In this paper, the $CP$ violating phase
parameters $\delta_{CP}^q$ and $\delta_{CP}^\ell$ in the standard
expression of $V_{CKM}$ and $U_{PMNS}$ are predicted as
$\delta_{CP}^q \simeq 72^\circ$
and $\delta_{CP}^\ell \simeq -76^\circ$, respectively,
i.e. $\delta_{CP}^\ell \sim - \delta_{CP}^q$.
(1) Revised version of 2014 (1): December 18, 2014
Publisehd in International Journal of Modern Physics A
(World Sci. Pub.)
Vol. 30 (2015) 1550017 (12 pages)
DOI: 10.1142/S0217751X15500177
Phenomenology of Harmless Family Gauge Bosons
to K^0-\bar{K}^0 Mixing
When we try to consider family gauge bosons with a lower
energy scale, a major obstacle is constraints from the
observed $P^0$-$\bar{P}^0$ mixings ($P^0=K^0, D^0, B^0,B^0_s$).
Against such a conventional view, we point out that, in a U(3)
family gauge boson model, the bosons are harmless
to any $P^0$-$\bar{P}^0$ mixings independently of explicit values
of the family mixings, if masses $M_{ij}$ of the gauge bosons
$A_i^{\ j}$ ($i,j$ are family indexes) satisfy a relation
$2/M_{ij}^2=1/M_{ii}^2 +1/M_{jj}^2$. If such the case can be
realized together with an inverted mass hierarchy
$M_{33}^2 \ll M_{22}^2 \ll M_{11}^2$, we can consider family
gauge bosons with a considerably lower scale, so that we can
expect rich signs for family gauge bosons in a TeV scale.
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