TY - JOUR
T1 - Can the nearly conformal sextet gauge model hide the Higgs impostor?
AU - Fodor, Zoltán
AU - Holland, Kieran
AU - Kuti, Julius
AU - Nógrádi, Dániel
AU - Schroeder, Chris
AU - Wong, Chik Him
N1 - Funding Information:
This work was supported by the DOE under grant DE-FG02-90ER40546 , by the NSF under grants 0704171 and 0970137 , by the EU Framework Programme 7 grant (FP7/2007-2013)/ERC No. 208740 , and by the Deutsche Forschungsgemeinschaft grant SFB-TR 55 . The simulations were performed using USQCD computational resources at Fermilab and JLab. Further support was provided by the UCSD GPU cluster funded by DOE ARRA Award ER40546 . Some of the simulations used allocations from the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number OCI-1053575 . In addition, some computational resources were used at the University of Wuppertal, Germany. We are grateful to Kalman Szabo and Sandor Katz for their code development building on Wuppertal GPU technology [99] . K.H. wishes to thank the Institute for Theoretical Physics and the Albert Einstein Center for Fundamental Physics at Bern University for their support.
PY - 2012/12/5
Y1 - 2012/12/5
N2 - New results are reported from large scale lattice simulations of a frequently discussed strongly interacting gauge theory with a fermion flavor doublet in the two-index symmetric (sextet) representation of the SU(3) color gauge group. We find that the chiral condensate and the mass spectrum of the sextet model are consistent with chiral symmetry breaking in the limit of vanishing fermion mass. In contrast, sextet fermion mass deformations of spectral properties are not consistent with leading conformal scaling behavior near the critical surface of a conformal theory. A recent paper could not resolve the conformal fixed point of the gauge coupling from the slowly walking scenario of a very small nearly vanishing β-function (DeGrand et al. [3]). It is argued that overall consistency with our new results is resolved if the sextet model is close to the conformal window, staying outside with a very small non-vanishing β-function. The model would exhibit then the simplest composite Higgs mechanism leaving open the possibility of a light scalar state with quantum numbers of the Higgs impostor. It would emerge as the pseudo-Goldstone dilaton state from spontaneous symmetry breaking of scale invariance. We will argue that even without association with the dilaton, the scalar Higgs-like state can be light very close to the conformal window. A new Higgs project of sextet lattice simulations is outlined to resolve these important questions.
AB - New results are reported from large scale lattice simulations of a frequently discussed strongly interacting gauge theory with a fermion flavor doublet in the two-index symmetric (sextet) representation of the SU(3) color gauge group. We find that the chiral condensate and the mass spectrum of the sextet model are consistent with chiral symmetry breaking in the limit of vanishing fermion mass. In contrast, sextet fermion mass deformations of spectral properties are not consistent with leading conformal scaling behavior near the critical surface of a conformal theory. A recent paper could not resolve the conformal fixed point of the gauge coupling from the slowly walking scenario of a very small nearly vanishing β-function (DeGrand et al. [3]). It is argued that overall consistency with our new results is resolved if the sextet model is close to the conformal window, staying outside with a very small non-vanishing β-function. The model would exhibit then the simplest composite Higgs mechanism leaving open the possibility of a light scalar state with quantum numbers of the Higgs impostor. It would emerge as the pseudo-Goldstone dilaton state from spontaneous symmetry breaking of scale invariance. We will argue that even without association with the dilaton, the scalar Higgs-like state can be light very close to the conformal window. A new Higgs project of sextet lattice simulations is outlined to resolve these important questions.
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U2 - 10.1016/j.physletb.2012.10.079
DO - 10.1016/j.physletb.2012.10.079
M3 - Article
AN - SCOPUS:84869886616
SN - 0370-2693
VL - 718
SP - 657
EP - 666
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
IS - 2
ER -