Taming the $\epsilon_K$ in Little Randall Sundrum Models

Abstract

The Randall Sundrum (RS) models receive significant constraints from the neutral Kaon system. The CP violating observable $\epsilon_K$, in Randall Sundrum scenario, requires the lightest KK gluon to be heavier than $\sim$ 24 TeV. The constraint is even stronger in the Little Randall Sundrum models (LRS), $\gtrsim$ 32 TeV. The LRS models are motivated for their possible visibility at the Large Hardon Collider (LHC). We show that the stringent constraints from K-physics can be relaxed in the LRS models, in the presence of the Brane Localised Kinetic Terms (BLKT). In particular, for a range of values, a UV BLKT could significantly modify the lightest KK gluon wave function such that the limit can reduces to 5 TeV. We also show that such a relaxation of the constraints can also be achieved by imposing flavour symmetries {\`a la } Minimal Flavour Protection.