Higgs inflation is among the most economical and predictive inflation models,
although the original Higgs inflation requires tuning the Higgs or top mass
away from its current experimental value by more than 2Ο deviations, and
generally gives a negligible tensor-to-scalar ratio rβΌ10β3 (if away
from the vicinity of critical point). In this work, we construct a minimal
extension of Higgs inflation, by adding only two new weak-singlet particles at
TeV scale, a vector-quark T and a real scalar S. The presence of singlets
(T,S) significantly impact the renormalization group running of the Higgs
boson self-coupling. With this, our model provides a wider range of the
tensor-to-scalar ratio r=O(0.1β10β3), consistent with the favored r
values by either BICEP2 or Planck data, while keeping the successful prediction
of the spectral index nsββ0.96. It further allows the Higgs and top
masses to fully fit the collider measurements. We also discuss implications for
searching the predicted TeV-scale vector-quark T and scalar S at the LHC
and future high energy pp colliders.Comment: 20pp, to match JCAP Final Versio