8,277 research outputs found

### Formulations of spin 1 resonances in the chiral lagrangian

Equivalence of the hidden local symmetry formulation with non-minimal
interactions and the anti-symmetric tensor field method of $\rho$ and $a_1$
mesons in the chiral lagrangian is shown by using the auxiliary field method.
Violation of the KSRF I relation, which becomes important in the application of
chiral lagrangian to {\em non QCD-like} technicolor models can be parametrized
by non-minimal coupling in the hidden local symmetry formalism keeping low
energy theorem of hidden local symmetry. We also obtain explicit correspondence
of parameters in both formulations.Comment: 14 pages, late

### Higgs Doublets as Pseudo Nambu-Goldstone Bosons in Supersymmetric E_6 Unification

The idea to have Higgs doublets as pseudo Nambu-Goldstone (PsNG) multiplet is
examined in the framework of supersymmetric E_6 unified theory. We show that
extra PsNG multiplets other than the expected Higgs doublets necessarily appear
in the E_6 case. If we demand that the extra PsNG multiplets neither disturb
the gauge coupling unification nor make the color gauge coupling diverge before
unification occurs, only possibility for the extra PsNG is 10+\bar{10} of
SU(5). This is realized when the symmetry breaking E_6 \to SO(10) occurs in the
\phi(27)+\phi(\bar{27}) sector while E_6 \to SU(4)_C\times SU(2)_L\times
U(1)\times U(1) in the \Sigma(78) sector. The existence of 10+\bar{10}
multiplets with mass around 1 TeV is therefore a prediction of this E_6 PsNG
scenario. Implication of their existence on the proton decay is also discussed.Comment: 16 pages, no figures, LaTeX(PTPTeX style

### Sterile Neutrinos in a Grand Unified Model

The recent experimental results indicating the neutrino oscillations may
strongly suggest that at least one more light neutrino species is required in
order to reconcile the existing data. In the simple GUT frameworks, this fact
seems difficult to preserve the parallelism between quarks and leptons. In this
letter, we investigate an SO(10) grand unified model with a pair of extra
generations in addition to the known three ones. Using the GUT relations, the
obtained neutrino mass matrix naturally indicates that one of the SU(2) singlet
(sterile) neutrino is very light and has large mixing with muon neutrino, which
can explain the atmospheric neutrino anomaly, and the hot dark matter neutrino
is also provided. The solar neutrino problem can be solved by the mixing with
muon neutrino consistently with quark mixing, namely, the Cabibbo angle.Comment: 15 pages, 5 eps figure

### A Signal for Technicolor?

We propose an interpretation for the ($l\bar l\gamma \gamma ,\ M_{\gamma
\gamma }=60{\rm GeV}$) events, which have recently been reported by L3 group at
LEP. This may be a first signal of `Technicolor' theory.Comment: 5pages, two Figures not included, phyzzx.te

### E_6 Unification with Bi-Large Neutrino Mixing

A scenario of SO(10) grand unified theory (GUT) proposed by one of the
authors is extended to E_6 unification. This gives realistic quark and lepton
mass matrices. In neutrino sector, the model reproduces large mixing angle
(LMA) MSW solution as well as large mixing angle for atmospheric neutrino
anomaly. In this model, right-handed down quark and left-handed lepton of the
first and second generation belong to a single multiplet 27. This causes
natural suppression of flavor changing neutral current(FCNC).Comment: 23 pages, V2:published versio

### Neutrino Mass Matrix Predicted From Symmetric Texture

Within the framework of grand unified theories, we make full analysis of
symmetric texture to see if such texture can reproduce large neutrino mixings,
which have recently been confirmed by the observed solar and atmospheric
neutrino oscillation experiments. It is found that so-called symmetric texture
with anomalous U(1) family symmetry with Froggatt-Nielsen mechanism does not
provide a natural explanation of two large mixing angles. On the contrary we
should adopt "zero texture" which have been extensively studied by many authors
and only this scenario can reproduce two large mixing angles naturally. Under
such "zero texture" with minimal symmetric Majorana matrix, all the neutrino
masses and mixing angles, 6 quantities, are expressed in terms of up-quark
masses, $m_t,m_c,m_u$ with two adjustable parameters. This provides interesting
relations among neutrio mixing angles, $\tan^2 2\theta_{12} \simeq
\frac{144m_c}{m_t} \tan^2 2\theta_{23} \cos^2 \theta_{23}, \quad \sin^2
\theta_{13} \simeq \frac{4m_c}{m_t}\sin^2 \theta_{23} \cos^2 \theta_{12}$. Thus
$|U_{e3}|$ is predicted to lie within the range $0.01-0.06$. Also absolute
masses of three neutrinos are predicted almost uniquely. This is quite in
contrast to the case where bi-large mixings come from the charged lepton sector
with non-symmetric mass matrix, which does not provide the information of
neutrino masses.Comment: 23 pages, latex, 15 figures. Preprint version contains "low
resolution" figures to reduce the size of overall postscript file. Please
contact authors to obtain the high resolution versio

### Neutrino Bi-Large Mixings and Family

After a brief review of quark-lepton relations in grand unified theories
(GUT), we show that the Pati-Salam relation with only one type of Higgs field
configuration with "four zero symmetric texture" can reproduce two large
neutrino mixings as well as observed mass differences. This is quite in
contrast to the case of SU(5) where bi-large mixings essentially come from the
charged lepton sector with non-symmetric charged lepton mass matrix.Comment: 6 pages, latex, uses ws-procs9x6.cls. Talk presented by Bando at 4th
Workshop on Neutrino Oscillations and their Origin (NOON2003), Kanazawa,
Japan, 10-14 Feb 2003. To appear in the proceeding

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