Eur. Phys. J. C (2013) 73: 2333
https://doi.org/10.1140/epjc/s10052-013-2333-x

Regular Article - Theoretical Physics

A higgs-like dilaton

¹ Dipartimento di Fisica e Astronomia, Università di Padova and INFN, Sezione di Padova, Via Marzolo 8, 35131, Padova, Italy
² SISSA, Via Bonomea 265, 34136, Trieste, Italy
³ Department of Physics, LEPP, Cornell University, Ithaca, NY, 14853, USA
⁴ Department of Physics, Syracuse University, Syracuse, NY, 13244, USA
⁵ Department of Physics, University of California, Davis, CA, 95616, USA

^* e-mail: brando.bellazzini@pd.infn.it

Received: 19 December 2012
Revised: 6 February 2013
Published online: 26 February 2013

Abstract

We examine the possibility that the recently discovered 125 GeV higgs-like resonance actually corresponds to a dilaton: the Goldstone boson of scale invariance spontaneously broken at a scale f. Comparing to LHC data we find that a dilaton can reproduce the observed couplings of the new resonance as long as f≈v, the weak scale. This corresponds to the dynamical assumption that only operators charged under the electroweak gauge group obtain VEVs. The more difficult task is to keep the mass of the dilaton light compared to the dynamical scale, Λ∼4πf, of the theory. In generic, non-supersymmetric theories one would expect the dilaton mass to be similar to Λ. The mass of the dilaton can only be lowered at the price of some percent level (or worse) tuning and/or additional dynamical assumptions: one needs to suppress the contribution of the condensate to the vacuum energy (which would lead to a large dilaton quartic coupling), and to allow only almost marginal deformations of the CFT.