Gravitational waves as a probe of the gravitino mass

Abstract

If gaugino condensations occur in the early universe, domain walls are produced as a result of the spontaneous breaking of a discrete R symmetry. Those domain walls eventually annihilate with one another, producing the gravitational waves. We show that the gravitational waves can be a probe for measuring the gravitino mass, if the constant term in the superpotential is the relevant source of the discrete R symmetry breaking.

Study of gravitational radiation from cosmic domain walls

“…There are several particle physics models which predict such phenomena. For instance, the spontaneous breaking of the discrete R symmetry in the theory with supersymmetry induces domain walls which decay when the Hubble parameter becomes comparable to the scale of the gravitino mass [18,19]. Also, the theory of axions, which was introduced in order to solve the strong CP problem of quantum chromodynamics, nat- * Electronic address: kawasaki@icrr.u-tokyo.ac.jp † Electronic address: saikawa@icrr.u-tokyo.ac.jp urally predicts the existence of domain walls [20,21].…”

A Review of Gravitational Waves from Cosmic Domain Walls

“…This result implies that there is a possibility to probe the gravitino mass from the observation of GWs [104]. For instance, if the domain wall annihilation occurs during the radiation dominated era, the peak frequency is given by f peak ∼ 10 3 Hz (m 3/2 /1 TeV) 1/2 .…”

“…In Refs. [104,105], the formation of domain walls and the production of GWs in the context of the spontaneous breaking of discrete R symmetries were discussed. Let us assume that there exist some hidden SU(N c ) gauge interactions in addition to those in the SM.…”

Light Gaugino Problem in Direct Gauge Mediation

“…If the Hubble parameter during the last inflation H inf exceeds the symmetry breaking scale m, or alternatively, if the highest temperature 6 of the breaking sector after inflation T H exceeds m, cosmic strings are formed [47,48] max [H inf , T H ] m.…”