Speaker
Prof.
Vincenzo Branchina
(University of Catania)
Description
One of the scenarios considered in these days explores the possibility
for the SM to be valid up to the Planck scale. The phase diagram for
the stability of the EW vacuum is then derived assuming that new
physics interactions at this scale have no impact on it. In
particular, for the central values of M_H and M_t, the EW vacuum is
metastable, and its lifetime is obtained ignoring new physics.
I show that, although new physics interactions appear in terms of
higher dimensional operators (and we could naively expect their
contribution to be suppressed), due to the non-perturbative nature of
the tunnelling, they can have great impact on the EW vacuum lifetime.
As a result, the SM phase diagram, far from being universal, strongly
depends on new physics. This has a far reaching consequences, as
specific BSM candidates can be tested against this stability analysis.
Finally, contrary to some claims, higher precision measurements of M_t
and M_H cannot provide any definite response on the stability of the
EW vacuum. The latter strongly depends on new physics.
Primary author
Prof.
Vincenzo Branchina
(University of Catania)
Paper
Paper files: