21-26 July 2014
Renold Building
Europe/London timezone
On the smallness of the cosmological constant in SUGRA models with Planck scale SUSY breaking and degenerate vacua
Presented by Dr. Roman NEVZOROV
Content
In $N=1$ supergravity (SUGRA) supersymmetric (SUSY) and non-supersymmetric Minkowski vacua originating in the hidden
sector can be degenerate. This allows for consistent
implementation of the multiple point principle (MPP)
assumption. We present no--scale inspired SUGRA model
where the MPP assumption is realised at the tree--level
without extra fine-tuning. In the supersymmetric phase in
flat Minkowski space SUSY may be broken dynamically inducing
tiny vacuum energy density which can be assigned, by virtue
of MPP, to all other phases including the one in which we
live. We argue that the measured value of the cosmological constant, as well as the small values of quartic Higgs
self--coupling and the corresponding beta function
at the Planck scale, which can be obtained by extrapolating
the Standard Model (SM) couplings to high energies, can
originate from supergravity (SUGRA) models with degenerate
vacua. This scenario is realised if there are at least
three exactly degenerate vacua. In the first vacuum,
associated with the physical one, local supersymmetry (SUSY)
is broken near the Planck scale while the breakdown of the $SU(2)_W\times U(1)_Y$ symmetry takes place at the
electroweak (EW) scale. In the second vacuum local
SUSY breaking is induced by gaugino condensation at a
scale which is just slightly lower than $\Lambda_{QCD}$
in the physical vacuum. Finally, in the third vacuum
local SUSY and EW symmetry are broken near the Planck
scale.
Place
Location: Renold Building
Room:
Co-authors
- Prof. Colin FROGGATT University of Glasgow
- Prof. Holger NIELSEN Niels Bohr Institute
- Prof. Anthony THOMAS University of Adelaide