Effective field theory in AdS: Continuum regime, soft bombs, and IR emergence
Abstract
We consider a scalar field in a slice of Lorentzian fivedimensional AdS at arbitrary energies. We show that the presence of bulk interactions separates the behavior of the theory into two different regimes: KaluzaKlein and continuum. We determine the transition scale between these regimes and show that UVbrane correlation functions are independent of IRbranelocalized operators for fourmomenta beyond this transition scale. The same bulk interactions that induce the transition also give rise to cascade decays. We study these cascade decays for the case of a cubic selfinteraction in the continuum regime. We find that the cascade decay progresses slowly towards the IR region and gives rise to soft spherical final states, in accordance with former results from both gravity and CFT. We identify a recursion relation between integrated squared amplitudes of different leg numbers and thus evaluate the total rate. We find that cascade decays in the continuum regime are exponentially suppressed. This feature completes the picture of the IR brane as an emergent sector as seen from the UV brane. We briefly discuss consistency with the holographic dual description of glueballs and some implications for dark sector models.
 Publication:

Physical Review D
 Pub Date:
 December 2020
 DOI:
 10.1103/PhysRevD.102.115038
 arXiv:
 arXiv:2002.12335
 Bibcode:
 2020PhRvD.102k5038C
 Keywords:

 High Energy Physics  Theory;
 High Energy Physics  Phenomenology
 EPrint:
 27 pages, 3 figures