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(7) arXiv:1311.5320 [hep-ph]: November 20, 2013
Phenomenology of Harmless Family Gauge Bosons to K^0-\bar{K}^0 Mixing
When we try to consider family gauge bosons with a visible 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, when masses $M_{ij}$ of the gauge bosons $A_i^j$
($i,j$ are family indexes) satisfy a relation
$2/M_{ij}^2=1/M_{ii}^2 +1/M_{jj}^2$, the bosons are harmless
to $P^0$-$\bar{P}^0$ mixings. In such the case, we can consider
family gauge bosons with a considerably lower scale.
Then, we can speculate many fruitful new physics in Tera scale
physics.
(6) arXiv:1309.4172 [hep-ph]: September 18, 2013
September 24, 2013: withdrawal due to a vital mistake
U(3)x[U(1)]^3 Model and Visible Family Gauge Boson Effects
A U(3) family gauge boson model is investigated based on
U(3)$\times$[U(1)]$^3$ gauge symmetry. In this model,
of nine U(3) family gauge bosons $A_i^{\ j}$,
those with $i=j$ are considerable heavy compared with those with
$i \neq j$, so that the model can be released from severe constraints
due to the observed $K^0$-$\bar{K}^0$ mixing, and so on. We speculate
that the lightest gauge boson is $A_2^{\ 3}$ and its mass is of $2 - 6$ TeV.
Thereby, visible effects of the family gauge bosons are discussed.
Especially, an observation of $\mu^- +N \rightarrow e^- + N$ versus
no observation of $\mu \rightarrow e +\gamma$ will be a promising test
for the present scenario.
For your reference, I put a revised version in which only
Eq.(6) was corrected, but other sentences were not corrected.
Therefore, the conclusion in this paper is still mistaken.
Modified manuscript (24 Sept. 2013)
(109 Kb)
(5) arXiv:1308.2129 [hep-ph]: August 09, 2013
Published in Physical Review D 88, 116004 (2013)
Yukawaon Model with Anomaly Free Set
of Quarks and Leptons in a U(3) Family Symmetry
Yoshio Koide and Hiroyuki Nishiura
In the so-called ``yukawaon" model, the (effective) Yukawa coupling
constants $Y_f^{eff}$ are given by vacuum expectation values (VEVs) of
scalars $Y_f$ (yukawaons) with $3\times 3$ components.
So far, yukawaons $Y_f$ have been assigned to ${\bf 6}$ or ${\bf 6}^*$
of U(3) family symmetry, so that quarks and leptons were not anomaly
free in U(3). In this paper, yukawaons are assigned to ${\bf 8}+{\bf 1}$
of U(3), so that quarks and leptons are anomaly free.
Since VEV relations among yukawaons are also considerably changed,
parameter fitting of the model is renewed. After fixing our free
parameters by observed mass ratios, we have only two and one
remaining free parameters for quark and lepton mixings, respectively.
We obtain successful predictions for the quark and lepton mixing parameters
including magnitudes of $CP$
violation. The effective Majorana neutrino mass is also predicted.
(4) arXiv:1305.7342 [hep-ph]: June 03, 2013
Revised version: December 30, 2013
Effective Valence Quark Model and
a Possible Dip in d Br(B -> K \ell \bar{\ell})/dq^2
Hiroyuki Ishida and Yoshio Koide
In rare B meson decays B\rightarrow K \ell^+ \ell^-,
a possible contribution of \ell^+\ell^- emission via photon
from the ``spectator" quark q (q=u,d) in the B meson
(q\bar{b}) is investigated in addition to the conventional one
\bar{b} \rightarrow \bar{s} +\gamma \rightarrow \bar{s}+\ell^+ + \ell^-.
If such a contribution is sizable compared with the standard
estimate of B\rightarrow K \ell^+ \ell^-, we will observe
visible difference between d \Gamma(B^0\rightarrow K^0 \ell^+ \ell^-)/d q^2
and d \Gamma(B^+\rightarrow K^+ \ell^+ \ell^-)/d q^2 in
q^2 dependence (q^2 \equiv m_{\ell\ell}^2).
Besides, as a result of the interference between the conventional
one and a new one, a dip appears in
d \Gamma(B\rightarrow K \ell^+ \ell^-)/d q^2 at a small region of q^2.
The interference effect in the B^0 decay will also be observed
differently from that in the B^+ decay. The calculation is done based on a
semi-classical approach, a valence quark model.
In the present model, the photon emission from the spectator
quark q, d \rightarrow d+\gamma (u \rightarrow u+\gamma)
is independent of the $b$-$s$ transition mechanism, and the
characteristic results are due to a straightforward estimate
of the quark propagator which cannot be incorporated into the factorization
method. The model is not a valence quark ``dominant" model,
so that, for example, the valence quarks in the final state carry
only 24% of the energy-momentum of the kaon.
(3) Revised version of the paper (7) in (2012)
MISC-2012-19, October 27, 2012
arXiv:1301.4312 [hep-ph]: January 21, 2013
Title was changed: January 18, 2013
Published in Journal of High Enery Physics, 04, 166 (2013),
April 30, 2013
doi:10.1007/JHEP04(2013)166
Neutrino Mass Matrix Model with a Bilinear Form
Yoshio Koide and Hiroyuki Nishiura
A neutrino mass matrix model with a bilinear form
$M_\nu = k_\nu (M_D M_R^{-1} M_D^T)^2$ is proposed
within the framework of the so-called yukawaon model, which has
been proposed for the purpose of a unified description of
the lepton mixing matrix $U_{PMNS}$
and the quark mixing matrix $V_{CKM}$.
The model has only two adjustable parameters for the PMNS mixing and
neutrino mass ratios.
(Other parameters are fixed from the observed quark and charged
lepton mass ratios and the CKM mixing.)
The model gives reasonable values $\sin^2 2\theta_{12} \simeq 0.85$
and $\sin^2 2\theta_{23} \sim 1$ and $\sin^2 2\theta_{13} \sim 0.09$
together with $R_\nu \equiv \Delta m^2_{21}/\Delta m^2_{32} \sim 0.03$.
Our prediction of the effective neutrino mass $\langle m \rangle$
in the neutrinoless double beta decay takes a sizable value
$\langle m \rangle \simeq 0.0034$ eV.
(2) Revised version of the paper (5) in (2012)
MISC-2012-18, August 25, 2012
arXiv:1209.1694 [hep-ph]: September 11, 2012
Title was changed: October 19, 2012
Published in Physical Review D87, 016016 (2013)
DOI: 10.1103/PhysRevD.87.016016
Can Mass of the Lightest Family Gauge Boson be of the Order of TeV?
The observed sign of a deviation from the $e$-$\mu$ universality
in tau decays suggests family gauge bosons with
an inverted mass hierarchy.
Under the constraints from the observed $K^0$-$\bar{K}^0$ and
$D^0$-$\bar{D}^0$ mixing, we investigate a possibility
that a mass $M_{33}$ of the lightest gauge boson $A_3^3$ which
couples with only the third generation quarks and leptons is of
the order of TeV.
It is concluded that $M_{33} \sim 1$ TeV is possible if we
adopt a specific model phenomenologically.
(1) Revised version of the paper (6) in (2012);
Accepted by EPJC
MISC-2012-17: September 06, 2012
arXiv:1209.1275 [hep-ph]: September 07, 2012
Published in Europian Physical Jurnal C73, 2277 (2013)
DOI 10.1140/epjc/s10052-013-2277-1
Large theta_{13}^\nu and Unified Description
of Quark and Lepton Mixing Matrices
Yoshio Koide and Hiroyukai Nishiura
We present a revised version of the so-called ``yukawaon model",
which was proposed
for the purpose of a unified description of the lepton mixing matrix
$U_{PMNS}$ and the quark mixing matrix $V_{CKM}$.
It is assumed from a phenomenological
point of view that the
neutrino Dirac mass matrix $M_D$ is given
with a somewhat different structure from the charged lepton
mass matrix $M_e$,
although $M_D=M_e$ was assumed in the previous model.
As a result, the revised model predicts a reasonable value
$\sin^2 2\theta_{13} \sim 0.07$ with keeping successful results for
other parameters in $U_{PMNS}$ as well as $V_{CKM}$ and quark
and lepton mass ratios.
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