Extending the Reach of the Cosmological Collider -- Soubhik Kumar (Berkeley)

Extending the Reach of the Cosmological Collider -- Soubhik Kumar (Berkeley)

The Cosmological Collider Physics program offers us an exciting, on-shell probe of very high energy particle physics through primordial non-Gaussianity (NG). As per this, inflationary Hubble-scale particles can lead to distinctive, oscillatory NG signatures. However, often the NGs mediated by super-Hubble particles are exponentially suppressed. Furthermore, the loop-level NGs mediated by charged particles can be negligibly small as well.

In this talk, I will describe a simple way in which the usual exponential suppression for heavy scalar particles is avoided, and consequently, one can probe particle masses as large as ~ 50 times the Hubble scale, in an on-shell way. I will then also describe how in the context of the curvaton paradigm, even charged particles can give rise observable NG in the near future -- thereby extending the reach of the Cosmological Collider.