Light scalar modes from holographic deformations

Abstract: We consider different ways of modifying the mass spectrum of a strongly coupled gauge theory with confinement using the AdS/CFT correspondence. Single- and multitrace deformations are introduced, such that the resulting theory has a mode lighter than the confinement scale. The multitrace deformation is shown to be a possible way of achieving a light composite mode, unlike the single-trace deformation where the light mode is an admixture of elementary and composite states.