557 research outputs found

### Supergravity Tensor Calculus in 5D from 6D

Supergravity tensor calculus in five spacetime dimensions is derived by
dimensional reduction from the d=6 superconformal tensor calculus. In
particular, we obtain an off-shell hypermultiplet in 5D from the on-shell
hypermultiplet in 6D. Our tensor calculus still retains the dilatation gauge
symmetry so that it becomes a trivial gauge fixing to make the Einstein term
canonical in a general matter-Yang-Mills-supergravity coupled system.Comment: 38 pages, no figures, LaTeX, version to appear in PTP
104(2000),835-86

### Off-shell d=5 Supergravity coupled to Matter-Yang-Mills System

We present an off-shell formulation of matter-Yang-Mills system coupled to
supergravity in five dimensional space-time. We give an invariant action for
the general system of vector multiplets and hypermultiplets coupled to
supergravity as well as the supersymmetry transformation rules. All the
auxiliary fields are kept un-eliminated so that the supersymmetry
transformation rules remain unchanged even when the action is changed.Comment: 36 pages, no figures, LaTeX, version to appear in PTP
105(2001),323-35

### Coupling Supersymmetric Nonlinear Sigma Models to Supergravity

It is known that supersymmetric nonlinear sigma models for the compact Kahler
manifolds G/H cannot be consistently coupled to supergravity, since the Kahler
potentials are not invariant under the G transformation. We show that the
supersymmetric nonlinear sigma models can be deformed such that the Kahler
potential be exactly G-invariant if and only if one enlarges the manifolds by
dropping all the U(1)'s in the unbroken subgroup H. Then, those nonlinear sigma
models can be coupled to supergravity without losing the G invariance.Comment: 14 pages, LaTeX2

### Two- and three-point Green's functions in two-dimensional Landau-gauge Yang-Mills theory

The ghost and gluon propagator and the ghost-gluon and three-gluon vertex of
two-dimensional SU(2) Yang-Mills theory in (minimal) Landau gauge are studied
using lattice gauge theory. It is found that the results are qualitatively
similar to the ones in three and four dimensions. The propagators and the
Faddeev-Popov operator behave as expected from the Gribov-Zwanziger scenario.
In addition, finite volume effects affecting these Green's functions are
investigated systematically. The critical infrared exponents of the
propagators, as proposed in calculations using stochastic quantization and
Dyson-Schwinger equations, are confirmed quantitatively. For this purpose
lattices of volume up to (42.7 fm)^2 have been used.Comment: 14 pages, 14 figures, 4 tables, references adde

### Gravitational Supersymmetry Breaking

We consider supersymmetry breaking models with a purely constant
superpotential in supergravity. The supersymmetry breaking is induced for the
vanishing cosmological constant. As a hidden mediation sector of supersymmetry
breaking, it naturally leads to a split spectrum in supersymmetric standard
model. We also point out possible utility of our setup to construct nonlinear
sigma model and/or Fayet-Iliopoulos-like term in broken supergravity.Comment: 6 page

### Mass Matrices in E6 Unification

We study a supersymmetric E6 grand unified model in which the SU(5) 5^*
components are twisted in the third generation 27. Supplementing the adjoint
Higgs field to a model analyzed previously, we calculate the mass matrices for
the up and down quarks and charged leptons. Although the number of free
parameters is less than that of observables, an overall fitting to the observed
masses and mixing angles is shown to be possible. Most notably, we find two
novel, parameter-independent relations between the lepton 2-3 mixing angle and
the quark masses and CKM mixing angles that are in good agreement with the
large lepton mixing recently observed.Comment: 33 pages, 5 figures, typos correcte

### Dynamical radion superfield in 5D action

We derive 5D N=1 superspace action including the radion superfield. The
radion is treated as a dynamical field and identified as a solution of the
equation of motion even in the presence of the radius stabilization mechanism.
Our derivation is systematic and based on the superconformal formulation of 5D
supergravity. We can read off the couplings of the dynamical radion superfield
to the matter superfields from our result. The correct radion mass can be
obtained by calculating the radion potential from our superspace action.Comment: 29 pages, no figures, LaTeX, some comments adde

### Large Lepton Mixing in a Coset-space Family Unification on $E_7/SU(5) \times U(1)^3$

We study a coset-space unification model for families based on $E_7/SU(5)
\times U(1)^3$. We find that qualitative structure of quark and lepton mass
matrices in this model describes very well the observation. We stress, in
particular, that the large mixing angle, $\sin^22\theta_{\nu_\mu\nu_\tau}
\simeq 1$, required for the atmospheric neutrino oscillation reported by the
SuperKamiokande collaboration, is naturally obtained, which is a consequence of
unparallel family structure in the present coset-space unification.Comment: 8 pages, Latex2

### Exploratory study of three-point Green's functions in Landau-gauge Yang-Mills theory

Green's functions are a central element in the attempt to understand
non-perturbative phenomena in Yang-Mills theory. Besides the propagators,
3-point Green's functions play a significant role, since they permit access to
the running coupling constant and are an important input in functional methods.
Here we present numerical results for the two non-vanishing 3-point Green's
functions in 3d pure SU(2) Yang-Mills theory in (minimal) Landau gauge, i.e.
the three-gluon vertex and the ghost-gluon vertex, considering various
kinematical regimes. In this exploratory investigation the lattice volumes are
limited to 20^3 and 30^3 at beta=4.2 and beta=6.0. We also present results for
the gluon and the ghost propagators, as well as for the eigenvalue spectrum of
the Faddeev-Popov operator. Finally, we compare two different numerical methods
for the evaluation of the inverse of the Faddeev-Popov matrix, the point-source
and the plane-wave-source methods.Comment: 18 pages, 12 figures, 3 table

### Superfield description of 5D supergravity on general warped geometry

We provide a systematic and practical method of deriving 5D supergravity
action described by 4D superfields on a general warped geometry, including a
non-BPS background. Our method is based on the superconformal formulation of 5D
supergravity, but is easy to handle thanks to the superfield formalism. We
identify the radion superfield in the language of 5D superconformal gravity,
and clarify its appearance in the action. We also discuss SUSY breaking effects
induced by a deformed geometry due to the backreaction of the radius
stabilizer.Comment: 25 pages, no figures, LaTeX, final version to appear in JHE

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