The scalar chemical potential in cosmological collider physics

A bstract Non-analyticity in co-moving momenta within the non-Gaussian bispectrum is a distinctive sign of on-shell particle production during inflation, presenting unique opportunity for “direct detection” particles with masses as large inflationary Hubble scale ( H ). However, strength such non-analyticity ordinarily drops exponentially by Boltzmann-like factor exceed . In this paper, we study an exception provided dimension-5 derivative coupling inflaton to heavy-particle currents, applying it specifically case two real scalars. The operator has “chemical potential” form, which harnesses kinetic energy inflaton, $$ {\overset{\cdot }{\phi}}_0^{1/2}\approx 60H ϕ ⋅ 0 1 / 2 ≈ 60 H , act efficient source scalar production. Derivative couplings ensure radiative stability slow-roll potential, turn maintains (approximate) scale-invariance correlations. We show that signal not suffering Boltzmann suppression can be obtained f NL ∼ \mathcal{O} O (0 01–10) extended range \lesssim }{\phi}}_0^{1/2} ≲ potentially high 10 15 GeV, sensitivity upcoming LSS and more futuristic 21-cm experiments. mechanism does invoke any particular fine-tuning parameters or breakdown perturbation-theoretic control. leading contribution appears at tree-level makes calculation analytically tractable removes loop-suppression compared earlier chemical potential studies non-zero spins. steady allows us infer effective mass heavy from variation oscillations function momenta. Our analysis sets stage generalization bosons spin.