Status of a minimal composite Higgs theory

Abstract

We analyze three sets of gauge ensembles in our extended physics program of a particularly important BSM gauge theory with a fermion doublet in the two-index symmetric (sextet) representation of the SU(3) BSM color gauge group. Our investigations include chiral symmetry breaking (χSB) in the p-regime and ε-regime, the mass of the composite 0 ++ scalar, resonance spectroscopy, new physics from gauge anomaly constraints, and the role of stable sextet BSM baryons with Electroweak interactions in dark matter searches. Important new goals include studies of the 0 ++ scalar entangled with Goldstone dynamics in the p-regime and the ε-regime, the resonance spectrum with particular attention to emerging LHC signals, like recent hints for diphoton excess at 750 GeV or diboson anomalies in the 2 TeV range. All results reported here are preliminary before journal publication including some post-conference material for the discussion.

Dilaton potential and lattice data

“…We commented briefly on the general form of all such corrections. It would be interesting to perform our analysis on the data of the SU (3) theory with N f = 2 sextets [6][7][8][9][10]. We also showed that loop corrections to the dilaton potential due to the finite pNGB mass yield counting factors of N 2 f − 1 that are accompanied by powers of y − 2.…”

“…Lattice studies of SU (3) gauge theories with matter field content consisting of N f = 8 fundamental (Dirac) fermions [1][2][3][4][5], as well as N f = 2 symmetric 2-index (Dirac) fermions (sextets) [6][7][8][9][10], have reported evidence of the presence in the spectrum of a light scalar, singlet particle, at least in the accessible range of fermion masses. Motivated by the possibility that such a particle might be a dilaton, the scalar particle associated with the spontaneous breaking of scale invariance, in Refs.…”

Review on Composite Higgs Models

“…mass or Decreasing M π Decreasing M π Figure 4: Spectrum in units of F π for the SU(3) sextet model with two flavors from Ref. [12]. Two values of the bare gauge coupling, β = 3.20 (left panel) and β = 3.25 (right panel), are investigated and simulations performed with rooted staggered fermions.…”

“…These Goldstone bosons are in turn "eaten" which results in the longitudinal components of the W ± and Z 0 boson. Examples for models focusing at this scenario are: an SU(2) gauge theory with two fundamental flavors explored by Drach et al [5][6][7][8], the two-flavor sextet model with SU(3) gauge group investigated by LatHC [9][10][11][12][13] and others [14,15], as well as an SU(3) gauge theory with eight fundamental flavors studied by the LatKMI [16,17] and the LSD collaboration [18,19].…”

Into the conformal window: Multirepresentation gauge theories

“…Such a new degree of freedom at low energy may be identified as a dilaton arising from the spontaneous breaking of scale symmetry, and can be used to extend the Higgs sector of the standard model of particle physics [31][32][33][34][35][36][37][38][39][40][41]. Interestingly, recent lattice studies of SU (3) gauge theories with 8 fundamental Dirac fermions [42][43][44][45], as well as 2 two-index symmetric Dirac fermions [46][47][48][49][50], performed with moderate sizes of the fermion mass found a relatively light scalar in the spectrum. There have been several attempts to analyze these results within a low-energy effective field theory (EFT) [51][52][53][54][55][56].…”