Dilaton potential and lattice data

Abstract

We study an effective field theory (EFT) describing the interaction of an approximate dilaton with a set of pseudo-Nambu-Goldstone bosons (pNGBs). The EFT is inspired by, and employed to analyse, recent results from lattice calculations that reveal the presence of a remarkably light singlet scalar particle. We adopt a simple form for the scalar potential for the EFT, which interpolates among earlier proposals. It describes departures from conformal symmetry, by the insertion of a single operator at leading order in the EFT. To fit the lattice results, the global internal symmetry is explicitly broken, producing a common mass for the pNGBs, as well as a further, additive deformation of the scalar potential. We discuss sub-leading corrections arising in the EFT from quantum loops. From lattice measurements of the scalar and pNGB masses and of the pNGB decay constant, we extract model parameter values, including those that characterise the scalar potential. The result includes the possibility that the conformal deformation is clearly nonmarginal. The extrapolated values for the decay constants and the scalar mass would then be not far below the current lattice-determined values.

Application of dilaton chiral perturbation theory to Nf=8 , SU(3) spectral data

“…With these caveats, we believe that dChPT provides a good explanation for the fermion-mass dependence of the taste splittings, which in this theory is very different from the analogous taste splittings in QCD, and for which standard staggered ChPT has not provided a convincing explanation. We do not claim that dChPT is the only possible explanation of these lattice data; it will be very interesting to test other low-energy approaches proposed in the literature [22][23][24][25][26][27][28][29][30][31], particularly if they can provide a valid description of the taste-breaking effects.…”

“…For other approaches to include the light scalar in a low-energy description, see Refs. [22][23][24][25][26][27][28][29][30][31].…”

Large $$N_c$$ scaling of meson masses and decay constants

“…Besides, lattice simulations have been used to perform studies of various observables in theories with different number of colours, flavours or fermion representations in the context of Beyond-the-Standard-Model theories. Some recent results can be found in [21][22][23][24][25][26] and for recent reviews see [27,28].…”

Dilaton portal in strongly interacting twin Higgs models

“…More specifically, in the infrared (IR) these couplings can be calculated in terms of: (a) the explicit breaking of scale invariance in the UV, and (b) the mass dimensions of the operators in the IR EFT. The phenomenology of the dilaton and the more formal aspects related to the dilaton potential have received a lot of attention in recent years [33][34][35][36][37][38]. Of most relevance to this work are the studies of dilaton phenomenology in composite SM extensions [39][40][41][42].…”