An O(750) GeV Resonance and Inflation

We study the possibility of a heavy scalar or pseudoscalar in TeV-scale beyond the Standard Model scenarios being the inflaton of the early universe in light of the recent O(750) GeV diphoton excess at the LHC. We consider a scenario in which the new scalar or pseudoscalar couples to the Standard Model gauge bosons at the loop level through new massive Standard Model charged vectorlike fermions with or without dark fermions. We calculate the renormalization group running of both the Standard Model and the new scalar couplings, and present two different models that are perturbative and with a stabilized vacuum up to near the Planck scale. Thus, the Standard Model Higgs and this possible new resonance may still preserve the minimalist features of Higgs inflation.