Distributed SUSY Breaking: Dark Energy, Newton's Law and the LHC
Abstract
We identify the underlying symmetry mechanism that suppresses the low-energy
effective 4D cosmological constant within 6D supergravity models, leading to
results suppressed by powers of the KK scale relative to the much larger masses
associated with particles localized on codimension-2 branes. In these models
the conditions for unbroken supersymmetry can be satisfied locally everywhere
within the extra dimensions, but are obstructed by global conditions like flux
quantization or the mutual inconsistency of boundary conditions at the various
branes. Consequently quantities forbidden by supersymmetry cannot be nonzero
until wavelengths of order the KK scale are integrated out, since only such
long wavelength modes see the entire space and so know that supersymmetry
breaks. We verify these arguments by extending earlier rugby-ball calculations
of one-loop vacuum energies to more general pairs of branes within two warped
extra dimensions. The predicted effective 4D vacuum energy density can be of
order C (m Mg/4 pi Mp)^4, where Mg (Mp) is the rationalized 6D (4D) Planck
scale and m is the heaviest brane-localized particle. Numerically this is C
(5.6 x 10^{-5} eV)^4 if we take m = 173 GeV and take Mg as small as possible
(10 TeV corresponding to KK size r < 1 micron), consistent with supernova
bounds. C is a constant depending on details of the bulk spectrum, which could
be ~ 500 for each of hundreds of fields. The value C ~ 6 x 10^6 gives the
observed Dark Energy density.