Gravity and electroweak symmetry breaking in a RSI/RSII hybrid model

Abstract

We present a hybrid RSI/RSII model in which we both solve the hierarchy problem and produce a continuum of Kaluza-Klein graviton modes. In this model, four-dimensional gravity can be reproduced, and the radion mode can be stabilized. We then modify the hybrid gravity model to include $\mathrm{SU}(2{)}_{L}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(2{)}_{R}\ifmmode\times\else\texttimes\fi{}\mathrm{U}(1{)}_{B\ensuremath{-}L}$ bulk gauge fields. Electroweak symmetry is broken by the choice of appropriate boundary conditions. By adjusting the size of one region of the extra dimension, we show that the $S$ parameter can be decreased while protecting the $\ensuremath{\rho}$ parameter from corrections. We find that as the $S$ parameter is decreased by $\ensuremath{\sim}60%$, ${M}_{{Z}^{\ensuremath{'}}}$ and ${M}_{{W}^{\ensuremath{'}}}$ stay below 1800 GeV, protecting unitarity.