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Nuclear Phyiscs (Proceedings Supplements) (Elsevier Pub)
DOI: 10.1016/j.nuclphys.2014.09.057
Hint of family gauge bosons with an inverted mass hierarchy
from the observed tau decays
The present data show a deviation from the e-m universality
$\varepsilon \equiv \varepsilon_\mu -\varepsilon_e =
0.0020 \pm 0.0016$.
If we consider that the deviation originates in a mass difference
between family gauge bosons $A_3^2$ and $A_3^1$, the sign of
the observed deviation suggests $\varepsilon_\mu >\varepsilon_e$,
i.e. mass relation $M(A_3^2)
arXiv:1410.8653 [hep-ph]: October 31, 2014
Published in Physical Review D (American Physical Society)
Vol. 90, Pages 117903-1 - 117903-5 (2014)
DOI: 10.1103/PhysRevD.90.117903
Leptonic CP violating Phase in the Yukawaon Model
Yoshio Koide and Hiroyuki Nisiura
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.
In this brief report, we change VEV forms $\langle Y_f \rangle$ in the
previous paper into a unified form.
Therefore, parameter fitting for quark and lepton masses and mixings
is revised.
Especially, we obtain predicted values of neutrino mixing $\sin^2 2\theta_{13}$
and a leptonic $CP$ violating phase $\delta_{CP}^\ell$ which are consistent
with the observed curve in the $(\sin^2 2\theta_{13}, \delta_{CP}^\ell)$
reported by T2K group recently.
arXiv:1405.6778 [hep-ph]: May 27, 2014
Phyiscs Letters B736 (2014) 499-505
DOI: 10.1016/j.physletb.2014.07.061
Spectroscopy of Family Gauge Bosons
Spectroscopy of family gauge bosons is investigated
based on a U(3) family gauge boson model proposed by
Sumino. In his model, the family gauge bosons are in mass
eigenstates in a diagonal basis of the charged
lepton mass matrix. Therefore, the family numbers are defined
by $(e_1,e_2, e_3)=(e, \mu, \tau)$,
while the assignment for quark sector are free.
For possible family-number assignments $(q_1, q_2, q_3)$,
under a constraint from $K^0$-$\bar{K}^0$ mixing, we investigate
possibilities of new physics, e.g. production of
the lightest family gauge boson
at the LHC, $\mu^- N \rightarrow e^- N$, rare $K$ and $B$ decays,
and so on.
arXiv:1405.0069 [hep-ph]: April 29, 2014
Revised verion: June 21, 2014
Physical Review D 90, 016009 (2014) (American Physical Society)
DOI: 10.1103/PhysRevD.90.016009
Universal Bilinear Form of Quark and Lepton Mass Matrices
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.
In the present model, all of the VEV matrices $\langle Y_f \rangle$
are given by a bilinear form of VEVs of flavons $\Phi_f$,
$\langle Y_f \rangle_i^{\ j} = k_f \langle \Phi_f\rangle_{ik}
\langle \bar{\Phi}_f\rangle^{kj}$, where
$\Phi_f$ is assigned to ${\bf 6}$ of U(3) family symmetry.
As input parameters with family-number dependent values,
we use only charged lepton mass values.
Under this formulation, we can give reasonable values of
quark and lepton masses and their mixings.
A $CP$ violating phase $\delta_{CP}^\ell=26^\circ$ in the lepton
sector is predicted.
The effective Majorana neutrino mass is also predicted.
CST-MICS Joint International Symposium on Particle Physics
CST Hall, Nihon University, Tokyo, March 15-16, 2014
To be appear in the Proceedings
Can Family Gauge Bosons Be Visible by Terrestrial Experiments?
Stimulated by the Sumino model and its extended model, we discuss a possibility
that we build a model of family gauge bosons which can be visible by
terrestrial experiments.
(2) Revised version of 2013 (4)
arXiv:1305.7342 [hep-ph]: June 03, 2013
Revised on February 3, 2014
Pubulished in The International Jounal of Modern Physics A
(World Scientific Publishing),
Vol. 29, No. 7 (2014) 1450040 (25 pages)
DOI: 10.1142/S0217751X14500407
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.
(1) Revised version of 2013 (7): March 172, 2014
For the published version of this article, see 2015 (1)
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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