No-scale hybrid inflation with R-symmetry breaking

In this paper we provide a no-scale supergravity scenario of hybrid inflation with R-symmetry being broken maximally. We investigate the inflation dynamics in details in both cases of pure F-term hybrid inflation and when adding constant Fayet-Iliopoulos D-terms. The effective inflation potential is asymptotically flat in a region of the parameter space in both cases. We explore all regions in the parameter space when discussing the constraints from the observables. We point out a connection between inflation, R-symmetry breaking and GUT scales. The moduli backreaction and SUSY breaking effects are investigated in a specific stabilization mechanism. We emphasis that a successful reheating is not affected by R-symmetry breaking, but it has interesting consequences. We study the reheating in flipped GUT model. We argue in favor of Z(2) symmetry associated with flipped GUT models to avoid phenomenologically dangerous operators and allow for decay channels for the inflaton to right-handed neutrinos (sneutrinos).

Automated summary

This paper presents a no-scale supergravity scenario of hybrid inflation with detailed investigation on inflation dynamics, emphasizing the connection between inflation, R-symmetry breaking, and GUT scales, as well as discussing parameters constrained by observables. Successful reheating is not influenced by R-symmetry breaking, but has interesting consequences. The study also explores reheating in the flipped GUT model and advocates for the Z(2) symmetry associated with it to avoid dangerous operators and allow decay channels for the inflaton to right-handed neutrinos (sneutrinos).