Top–Bottom Condensation Model: Symmetries and Spectrum of the Induced 2HDM

Abstract

Here, we use the Schwinger–DeWitt approach to address the four-fermion composite Higgs effective model proposed by Miransky, Tanabashi and Yamawaki (MTY). The surprising benefit of such an approach is that it is possible to ascribe to a SM-type Higgs a quark–antiquark structure of predominantly a b¯b nature with a small t¯t admixture, which in turn yields a Higgs mass compatible with the observed value of 125 GeV. We discuss this result in a detailed and pedagogical way, as it goes against the common belief that this model and akin composite descriptions should predict a Higgs mass-of-order of twice the top quark mass, contrary to empirical evidence. A further aspect of this approach is that it highlights the link of the SU(2)L×U(1)R symmetric four-fermion MTY model interactions of the heavy quark family to a specific two-Higgs-doublet model (2HDM), and the necessity to go beyond the one Higgs doublet to obtain the empirical Higgs mass within composite models. By appropriately fixing the symmetry-defining interaction parameters, we show that the resulting CP-preserving spectrum harbors the following collective states at the electroweak scale ΛEW=246 GeV: a light scalar to which the standard Higgs is associated; a heavier neutral state preconized as the Nambu partner of the standard Higgs within the Nambu sum rule; the expected triplet of Goldstone bosons associated with the longitudinal polarizations of the electroweak massive bosons; and a neutral pseudoscalar state that in the limit of a global U(1)A symmetry would be a Goldstone mode. The anomalous breaking of this axial symmetry is a subleading effect in a large Nc counting scheme, and we discuss how it modifies the leading-order Nambu sum rule result and its relevance for the qualitative description of the spectrum.

Higher Order Radiative Corrections in QCD

“…• WG1: "Innovative Quantum Field Theory" with the goal of developing innovative cutting edge algorithms to push the precision frontier forward, aiding the development of computational tools, computer algebra implementations, and proof-of-concept computations [1][2][3][4]. • WG2: "Precision Phenomenology" to provide precise theoretical predictions for LHC in the high-energy run to push the frontiers regarding precision and sensitivity; to compute cross sections for Higgs boson production (single and multiple Higgs boson production), EW gauge bosons, heavy-quark, multi-jet, and ultra-rare processes in differential kinematics [5][6][7]. • WG3: "Future Colliders" to assess the discovery potential of future high energy colliders based on the experimental results from the high-energy run of the LHC combined with progress in theoretical research [8,9].…”