  We are in the era of precision cosmology which offers us a unique opportunity
to investigate beyond standard model physics. Toward this endeavor, inflaton is
assumed to be a perfect new physics candidate. In this submission, we explore
the phenomenological impact of the latest observation of PLANCK and
BICEP/$Keck$ data on the physics of inflation. We particularly study three
different models of inflation, namely $\alpha$-attractor E, T, and the minimal
plateau model. We further consider two different post-inflationary reheating
dynamics driven by inflaton decaying into bosons and fermions. Given the latest
data in the inflationary $(n_s-r)$ plane, we derive detailed phenomenological
constraints on different inflaton parameters and the associated physical
quantities, such as inflationary $e$-folding number, $N_{ k}$, reheating
temperatures $T_{\rm re}$. Apart from considering direct observational data, we
further incorporate the bounds from primordial gravitational waves (PGWs) and
different theoretical constraints. Rather than in the laboratory, our results
illustrate the potential of present and future cosmological observations to
look for new physics in the sky.
