arXiv subjects
Publications and source records attributed to M. Cardella.
We prove the impossibility of resonant decay of a metastable vacuum in a theory of a scalar field coupled to a gauge field. Our result extends to gauge theories of scalar fields a recent no go theorem for resonant tunneling in a pure scalar field theory.
The one-loop vacuum energy is explicitly computed for a class of perturbative string vacua where supersymmetry is spontaneously broken by a T-duality invariant asymmetric Scherk-Schwarz deformation. The low-lying spectrum is tachyon-free for any value of the compactification radii and thus no Hagedorn-like phase-transition takes place. Indeed, the induced effective potential is free of divergence, and has a global anti de Sitter minimum where geometric moduli are naturally stabilised.
We study the effect of Scherk-Schwarz deformations on intersecting branes. Non-chiral fermions in any representation of the Chan-Paton gauge group generically acquire a tree-level mass dependent on the compactification radius and the brane wrapping numbers. This offers an elegant solution to one of the long-standing problems in intersecting-brane-world models where the ubiquitous presence of massless non-chiral fermions is a clear embarrassment for any attempt to describe the Standard Model of Particle Physics.