TY - JOUR

T1 - Viable chaotic inflation as a source of neutrino masses and leptogenesis

AU - Nakayama, Kazunori

AU - Takahashi, Fuminobu

AU - Yanagida, Tsutomu T.

N1 - Funding Information:
T.T.Y. thanks Prof. Raymond Volkas for the hospitality during his stay at the University of Melbourne. This work was supported by the Grant-in-Aid for Scientific Research on Scientific Research A (No. 26247042 [KN and FT]), Scientific Research B (No. 26287039 [FT and TTY]), Young Scientists B (No. 26800121 [KN], No. 24740135 [FT]) and Innovative Areas (No. 26104009 [KN], No. 15H05888 [KN], No. 23104008 [FT], and No. 15H05889 [FT]). This work was supported by World Premier International Research Center Initiative (WPI Initiative), MEXT , Japan.
Publisher Copyright:
© 2016 The Authors.

PY - 2016/6/10

Y1 - 2016/6/10

N2 - We show that the seesaw mechanism as well as leptogenesis are natural outcomes of a viable chaotic inflation in supergravity. The inflation model contains two superfields, the inflaton and stabilizer fields, which, being singlets under the standard model gauge symmetry, naturally couple to the lepton and Higgs doublets. The inflaton decays into leptons and Higgs fields, and the reheating temperature is predicted to be of O(1013) GeV, for which thermal leptogenesis is possible. On the other hand, gravitinos are copiously produced, and various solutions to the gravitino problem are discussed. We also argue that, if the shift symmetry of the inflaton is explicitly broken down to a discrete one, neutrino Yukawa couplings are periodic in the inflaton field, and masses of leptons and Higgs do not blow up even if the inflaton takes super-Planckian field values. The inflaton potential is given by a sum of sinusoidal functions with different height and periodicity, the so-called multi-natural inflation. We show that the predicted scalar spectral index and tensor-to-scalar ratio lie in the region favored by the Planck data.

AB - We show that the seesaw mechanism as well as leptogenesis are natural outcomes of a viable chaotic inflation in supergravity. The inflation model contains two superfields, the inflaton and stabilizer fields, which, being singlets under the standard model gauge symmetry, naturally couple to the lepton and Higgs doublets. The inflaton decays into leptons and Higgs fields, and the reheating temperature is predicted to be of O(1013) GeV, for which thermal leptogenesis is possible. On the other hand, gravitinos are copiously produced, and various solutions to the gravitino problem are discussed. We also argue that, if the shift symmetry of the inflaton is explicitly broken down to a discrete one, neutrino Yukawa couplings are periodic in the inflaton field, and masses of leptons and Higgs do not blow up even if the inflaton takes super-Planckian field values. The inflaton potential is given by a sum of sinusoidal functions with different height and periodicity, the so-called multi-natural inflation. We show that the predicted scalar spectral index and tensor-to-scalar ratio lie in the region favored by the Planck data.

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U2 - 10.1016/j.physletb.2016.03.051

DO - 10.1016/j.physletb.2016.03.051

M3 - Article

AN - SCOPUS:84961901867

VL - 757

SP - 32

EP - 38

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

SN - 0370-2693

ER -