Light inflaton Hunter's Guide
  We study the phenomenology of a realistic version of the chaotic inflationary
model, which can be fully and directly explored in particle physics
experiments. The inflaton mixes with the Standard Model Higgs boson via the
scalar potential, and no additional scales above the electroweak scale are
present in the model. The inflaton-to-Higgs coupling is responsible for both
reheating in the Early Universe and the inflaton production in particle
collisions. We find the allowed range of the light inflaton mass, 270
MeV<~m_chi<~1.8 GeV, and discuss the ways to find the inflaton. The most
promising are two-body kaon and B-meson decays with branching ratios of orders
10^{-9} and 10^{-6}, respectively. The inflaton is unstable with the lifetime
10^{-9}--10^{-10} s. The inflaton decays can be searched for in a beam-target
experiment, where, depending on the inflaton mass, from several billions to
several tenths of millions inflatons can be produced per year with modern
high-intensity beams.
