title: A naturally light dilaton and a small cosmological constant.
abstract: We present a non-supersymmetric theory with a naturally light dilaton. It is based on a 5D holographic description of a conformal theory perturbed by a close-to-marginal operator of dimension [Formula: see text] which develops a condensate. As long as the dimension of the perturbing operator remains very close to marginal (even for large couplings) a stable minimum at hierarchically small scales is achieved, where the dilaton mass squared is suppressed by [Formula: see text]. At the same time the cosmological constant in this sector is also suppressed by [Formula: see text], and thus it is parametrically smaller than in a broken SUSY theory. As a byproduct we also present an exact solution to the scalar-gravity system that can be interpreted as a new holographic realization of spontaneously broken conformal symmetry. Even though this metric deviates substantially from AdS space in the deep IR it still describes a non-linearly realized exactly conformal theory. We also display the effective potential for the dilaton for arbitrary holographic backgrounds.
authors: Institut de Physique Théorique, CEA-Saclay, 91191  Gif-sur-Yvette Cedex, France ; Dipartimento di Fisica e Astronomia, Università di Padova and INFN, Sezione di Padova, Via Marzolo 8, 35131  Padua, Italy.
authors: Brando
authors: B
authors: Bellazzini
authors: Department of Physics, LEPP, Cornell University, Ithaca, NY 14853 USA.
authors: Csaba
authors: C
authors: Csáki
authors: Department of Physics, Syracuse University, Syracuse, NY 13244 USA.
authors: Jay
authors: J
authors: Hubisz
authors: Department of Physics, LEPP, Cornell University, Ithaca, NY 14853 USA.
authors: Javi
authors: J
authors: Serra
authors: Department of Physics, University of California, Davis, CA 95616 USA.
authors: John
authors: J
authors: Terning