Generalised Holographic Electroweak Symmetry Breaking Models and the   Possibility of Negative S
  Within an AdS/CFT inspired model of electroweak symmetry breaking the effects of various boundary terms and modifications to the background are studied. The effect on the S precision parameter is discussed with particular attention to its sign and whether the theory is unitary when S<0. Connections between the various possible AdS slice models of symmetry breaking are discussed. 
Mark Round
hep-ph