https://doi.org/10.1140/epjc/s10052-019-7449-1
Regular Article - Theoretical Physics
Conformal GUT inflation, proton lifetime and non-thermal leptogenesis
1
Departamento de Física, Centro de Matemática e Aplicações (CMA-UBI), Universidade da Beira Interior, 6200, Covilhã, Portugal
2
Southern University of Science and Technology (SUSTech), Shenzhen, 518055, China
3
Van Swinderen Institute, University of Groningen, 9747 AG, Groningen, The Netherlands
4
DAMTP, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA, UK
5
Clare Hall, University of Cambridge, Hershel Road, Cambridge, CB3 9AL, UK
* e-mail: sravan@ubi.pt
** e-mail: korumilli@sustc.edu.cn
*** e-mail: sravan.korumilli@rug.nl
Received:
6
September
2018
Accepted:
2
November
2019
Published online:
19
November
2019
In this paper, we generalize Coleman–Weinberg (CW) inflation in grand unified theories (GUTs) such as 
and 
by means of considering two complex singlet fields with conformal invariance. In this framework, inflation emerges from a spontaneously broken conformal symmetry. The GUT symmetry implies a potential with a CW form, as a consequence of radiative corrections. The conformal symmetry flattens the above VEV branch of the CW potential to a Starobinsky plateau. As a result, we obtain 
and 
for 
50–60 e-foldings. Furthermore, this framework allow us to estimate the proton lifetime as 
years, whose decay is mediated by the superheavy gauge bosons. Moreover, we implement a type I seesaw mechanism by weakly coupling the complex singlet, which carries two units of lepton number, to the three generations of singlet right handed neutrinos (RHNs). The spontaneous symmetry breaking of global lepton number amounts to the generation of neutrino masses. We also consider non-thermal leptogenesis in which the inflaton dominantly decays into heavy RHNs that sources the observed baryon asymmetry. We constrain the couplings of the inflaton field to the RHNs, which gives the reheating temperature as 
GeV.
© The Author(s), 2019
