Speaker
Description
A new gauge singlet scalar field can undergo a strongly
first-order phase transition leading to gravitational waves observable
at aLIGO and stabilizes the electroweak vacuum at the same time. This
is because the sensitivity of aLIGO to cosmological phase transitions
at 10^7-10^8 GeV coincides with the requirement that the singlet scale
is close to the Standard Model instability scale. Extending the SM
with a singlet, we calculate the nucleation temperature and order
parameter of the PT during which the singlet acquires a vacuum
expectation value in terms of Lagrangian parameters. Relating the
thermodynamic quantities to the peak frequency and amplitude of the
gravitational waves created during the phase transition, we present
three benchmark points for which not only are gravitational waves
observable at aLIGO but the electroweak vacuum is stable and the zero
temperature phenomenology is acceptable. This scenario offers an
intriguing possibility for aLIGO to detect traces of fundamental
physics motivated by vacuum stability at an energy scale that is well
above the reach of any other experiments.
