2024/07/23 by Oller, J. A., Peláez, Marcela
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th)
paper · doi:10.48550/arxiv.2407.16538
From the graviton-graviton scattering amplitudes calculated perturbatively in quantum gravity to the one-loop order, we develop further a formalism that allows one to calculate infrared-finite partial-wave amplitudes fulfilling perturbative unitarity. As a result of this process a parameter dubbed ln a emerges that separate between infrared and typical external momenta. The resulting partial-wave amplitudes are next unitarized by employing the Inverse Amplitude Method and the algebraic-N/D method. Then, the graviball resonance, with a similar pole position, is confirmed in the S-wave partial-wave amplitude for all unitarization methods, also with respect to the unitarization of only the leading-order amplitude. Although the spectrum of the theory is independent of the specific value of ln a, the requirement for a well-behaved unitarized effective field theory of gravity identifies the optimal range of ln a for our next-to-leading-order calculations as 0.5 \lesssim ln a \lesssim 1.7. Briefly, we discuss the D-wave scattering that is weaker than the S-wave scattering, repulsive and non-resonant for ln a≈ 1.