Charanjit S. Aulakh, Ila Garg
Supersymmetric Unified theories which incorporate a renormalizable Type I seesaw mechanism for small neutrino masses can also provide slow roll inflection point inflation along a flat direction associated with a gauge invariant combination of the Higgs, slepton and right handed sneutrino superfields. Inflationary parameters are related to the Majorana and Dirac couplings responsible for neutrino masses with the scale of inflation set by the lightest right-handed neutrino mass $M_{\nu^c} \sim 10^6-10^{10}$ GeV. Tuning of the neutrino Dirac and Majorana superpotential couplings and soft Susy breaking parameters is required to enforce flatness of the inflationary potential. In contrast to previous inflection point inflation models, provided $M_{\nu^c}>>M_{Susy}$, the tuning is almost independent of the soft parameters and thus radiatively stable. The fine tuning required for Type I seesaw inflation is less stringent than in the case of MSSM inflation or Dirac neutrino inflation due to the much larger value of the inflaton mass, and thus requires no additional dynamics to make it plausible. The high reheat temperature after inflation $T_{rh} \sim 10^{11}- 10^{14} $ GeV requires large gravitino masses $> 50 $ TeV and is also favourable to Leptogenesis since it facilitates production of right handed neutrinos. Our scenario is motivated and illustrated by the completely realistic New Minimal Supersymmetric SO(10) GUT which also requires large Supersymmetry breaking scales $\sim 10^ 2 $ TeV.
View original:
http://arxiv.org/abs/1201.0519
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