Speaker
Dr.
Roman Nevzorov
(University of Adelaide)
Description
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.
Primary author
Dr.
Roman Nevzorov
(University of Adelaide)
Co-authors
Prof.
Anthony Thomas
(University of Adelaide)
Prof.
Colin Froggatt
(University of Glasgow)
Prof.
Holger Nielsen
(Niels Bohr Institute)
