265 research outputs found
Higher dimensional supersymmetry in 4D superspace
We present an explicit formulation of supersymmetric Yang-Mills theories from
\D= 5 to 10 dimensions in the familiar \N=1,\D=4 superspace. This provides
the rules for globally supersymmetric model building with extra dimensions and
in particular allows us to simply write down SUSY preserving
interactions between bulk fields and fields localized on branes. We present a
few applications of the formalism by way of illustration, including
supersymmetric ``shining'' of bulk fields, orbifolds and localization of chiral
fermions, anomaly inflow and super-Chern-Simons theories.Comment: Typos corrected. Added reference to early work by Marcus, Sagnotti
and Siegel and a term to the non-Abelian Lagrangian for D>5 formally needed
for gauge invariance. The results however remain unchange
Breaking the electroweak symmetry and supersymmetry by a compact extra dimension
We revisit in some more detail a recent specific proposal for the breaking of
the electroweak symmetry and of supersymmetry by a compact extra dimension.
Possible mass terms for the Higgs and the matter hypermultiplets are considered
and their effects on the spectrum analyzed. Previous conclusions are reinforced
and put on firmer ground.Comment: 25 pages, LaTeX, 9 eps figure
Towards 5D Grand Unification without SUSY Flavor Problem
We consider the renormalization group approach to the SUSY flavor problem in
the supersymmetric SU(5) model with one extra dimension. In higher dimensional
SUSY gauge theories, it has been recently shown that power corrections due to
the Kaluza-Klein states of gauge fields run the soft masses generated at the
orbifold fixed point to flavor conserving values in the infra-red limit. In
models with GUT breaking at the brane where the GUT scale can be larger than
the compactification scale, we show that the addition of a bulk Higgs
multiplet, which is necessary for the successful unification, is compatible
with the flavor universality achieved at the compactification scale.Comment: JHEP style file of 35 pages with 3 figures, Version to appear in JHE
Brane-induced supersymmetry breaking
We study spontaneous supersymmetry breaking induced by brane-localized
dynamics in five-dimensional supergravity compactified on S^1/Z_2. We consider
a model with gravity in the bulk and matter localized on tensionless branes at
the orbifold fixed points. We assume that the brane dynamics give rise to
effective brane superpotentials that trigger the supersymmetry breaking. We
analyze in detail the super-Higgs effect. We compute the full spectrum and show
that the symmetry breaking is spontaneous but nonlocal in the fifth dimension.
We demonstrate that the model can be interpreted as a new, non-trivial
implementation of a coordinate-dependent Scherk-Schwarz compactification.Comment: 15 pages. v2: improved treatment of brane actions, relation with
conventional Scherk-Schwarz mechanism clarified, version to be published in
JHE
Gauged Symmetries and Fayet-Iliopoulos Terms in 5D Orbifold Supergravity
We discuss a gauged supergravity on five-dimensional (5D) orbifold
() in which both a -even U(1) gauge field and the -odd
graviphoton take part in the gauging. Based on the off-shell
formulation of 5D supergravity, we analyze the structure of Fayet-Iliopoulos
(FI) terms allowed in such model. Introducing a -even gauge field
accompanies new bulk and boundary FI terms in addition to the known integrable
boundary FI term which could be present in the absence of any gauged
symmetry. Some physical consequences of these new FI terms are examined.Comment: 1+17 pages, 9 figures, typeset in JHEP styl
Bhabha Scattering with Radiated Gravitons at Linear Colliders
We study the process e+- e- -> e+- e- +- missing energy at a high-energy e+-
e- collider, where the missing energy arises from the radiation of Kaluza-Klein
gravitons in a model with large extra dimensions. It is shown that at a
high-energy linear collider, this process can not only confirm the signature of
such theories but can also sometimes be comparable in effectiveness to the
commonly discussed channel e+- e- -> gamma +- missing energy, especially for a
large number of extra dimensions and with polarized beams. We also suggest some
ways of distinguishing the signals of a graviton tower from other types of new
physics signals by combining data on our suggested channel with those on the
photon-graviton channel.Comment: 16 pages, LaTex, 8 figures embedded, typos, report no and references
correcte
Exponentially Small Supersymmetry Breaking from Extra Dimensions
The supersymmetric ``shining'' of free massive chiral superfields in extra
dimensions from a distant source brane can trigger exponentially small
supersymmetry breaking on our brane of order e^{-2 pi R}, where R is the radius
of the extra dimensions. This supersymmetry breaking can be transmitted to the
superpartners in a number of ways, for instance by gravity or via the standard
model gauge interactions. The radius R can easily be stabilized at a size O(10)
larger that the fundamental scale. The models are extremely simple, relying
only on free, classical bulk dynamics to solve the hierarchy problem.Comment: RevTex, 1 figure. Comment on mu problem adde
Energy Spectra of Reactor Neutrinos at KamLAND
The upcoming reactor neutrino experiment, KamLAND, has the ability to explore
the Large Mixing Angle (LMA) solution to the solar neutrino problem. Here, we
investigate the precision to which KamLAND should be able to measure these
parameters, utilizing the distortion of the energy spectrum of reactor
neutrinos. Incomplete knowledge of the fuel composition of the reactors will
lead to some error on this measurement. We estimate the size of this effect.Comment: 7 pages, 7 figures. References added. Minor changes in wordin
Kaluza-Klein Structure Associated With Fat Brane
It is known that the imposition of orbifold boundary conditions on background
scalar field can give rise to a non-trivial vacuum expectation value (VEV)
along extra dimensions, which in turn generates fat branes and associated
unconventional Kaluza-Klein (KK) towers of fermions. We study the structure of
these KK towers in the limit of one large extra dimension and show that
normalizable (bound) states of massless and massive fermions can exist at both
orbifold fixed points. Closer look however indicates that orbifold boundary
conditions act to suppress at least half of bound KK modes, while periodic
boundary conditions tend to drive the high-lying modes to the conventional
structure. By investigating the scattering of fermions on branes, we
analytically compute masses and wavefunctions of KK spectra in the presence of
these boundary conditions up to one-loop level. Implication of KK-number
non-conservation couplings on the Coulomb potential is also examined.Comment: RevTex4, 29 pages, 7 ps figures, new references adde
R-mediation of Dynamical Supersymmetry Breaking
We propose a simple scenario of the dynamical supersymmetry breaking in four
dimensional supergravity theories. The supersymmetry breaking sector is assumed
to be completely separated as a sequestered sector from the visible sector,
except for the communication by the gravity and U(1)_R gauge interactions, and
the supersymmetry breaking is mediated by the superconformal anomaly and U(1)_R
gauge interaction. Supersymmetry is dynamically broken by the interplay between
the non-perturbative effect of the gauge interaction and Fayet-Iliopoulos
D-term of U(1)_R which necessarily exists in supergravity theories with gauged
U(1)_R symmetry. We construct an explicit model which gives phenomenologically
acceptable mass spectrum of superpartners with vanishing (or very small)
cosmological constant.Comment: 12 pages, to be published in Phys. Rev.
- …