Helical inflation correlators: partial Mellin-Barnes and bootstrap equations

Massive spinning particles acquire helicity-dependent chemical potentials during the inflation from axion-type couplings. Such fields can mediate sizable inflaton correlators which we call helical correlators. Helical are approximately scale invariant, dS boost breaking, parity-violating, and promising observables of cosmological collider physics. In this work, present complete analytical results for 4-point with tree-level exchanges massive particles, including both smooth background oscillatory signals. We compute bulk Schwinger-Keldysh integrals in two independent ways, partial Mellin-Barnes representation solving bootstrap equations. also new closed-form 3-point functions scalar or exchanges. The allow us to concretely efficiently explore phenomenological consequences potentials. particular, show that potential exponentially enhance signals local nonlocal types, but only affects a rather mild way. Our extend de Sitter program include nonperturbative breaking boosts. explicitly verify recently proposed cutting rule