Scalar excitation with Leggett frequency inHe3−Band the 125 GeV Higgs particle in top quark condensation models as pseudo-Goldstone bosons

Abstract

We consider the scenario in which the light Higgs scalar boson appears as the pseudo-Goldstone boson. We discuss examples in both condensed matter and relativistic field theory. In 3 He-B the symmetry breaking gives rise to four Nambu-Goldstone (NG) modes and 14 Higgs modes. At lower energy one of the four NG modes becomes the Higgs boson with a small mass. This is the mode measured in experiments with the longitudinal NMR, and the Higgs mass corresponds to the Leggett frequency M H ¼ ℏΩ B . The formation of the Higgs mass is the result of the violation of the hidden spin-orbit symmetry at low energy. In this scenario the symmetry-breaking energy scale Δ (the gap in the fermionic spectrum) and the Higgs mass scale M H are highly separated: M H ≪ Δ. (2014)]. At high energies the SU(3) symmetry is assumed which relates the left-handed top and bottom quarks to the additional fermion χ L . This symmetry is softly broken at low energies. As a result the only CP-even Goldstone boson acquires a mass and may be considered as a candidate for the 125 GeV scalar boson. We consider a condensation pattern different from that typically used in top-seesaw models, where the condensate ht L χ R i is off-diagonal. In our case the condensates are mostly diagonal. Unlike the work of Cheng et al. [J. High Energy Phys. 08 (014) 095] and Fukano et al. [Phys. Rev. D 90, 055009 (2014)], the explicit mass terms are absent and the soft breaking of SU(3) symmetry is given solely by the four-fermion terms. This reveals a complete analogy with 3 He, where there is no explicit mass term and the spin-orbit interaction has the form of the four-fermion interaction.

Modified top quark condensation model with the extra heavy fermion, the 125 GeV pseudo-Goldstone boson, and the additional heavy scalar bosons

“…It appears, that without the additional ingredients in the model of [54] the value of the cross -section for the process pp → H ′ + X → γγ + X is much smaller than the upper bounds indicated by ATLAS and CMS [3,4]. This means, that this model is in accordance with the present experimental data on the γγ channel.…”

“…The paper is organized as follows. In Section II we briefly remind the construction of [54], in which the Pseudo -Goldstone boson composed of top quark and the heavy fermion χ plays the role of the 125 GeV Higgs boson. In Section III we present the effective lagrangian for the decays of the CP -even composite scalar bosons.…”

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We discuss the modified top quark condensation model proposed in [54]. This construction was inspired by the top -seesaw scenario, in which the extra heavy fermion χ is added that may be paired with the top quark.

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Polar Phase of Superfluid 3He: Dirac Lines in the Parameter and Momentum Spaces

“…In the other language these two branches correspond respectively to the optical magnon and the light Higgs mode. 25,26 The modes do not interact with each other only at λ = π/2 and at λ = 0. Otherwise, these modes interact producing the observed parametric decay of Bose-Einstein condensate of optical magnons to light Higgs modes, 25 and the repulsion of the levels -the observed avoiding crossing.…”

Minimal Coleman-Weinberg theory explains the diphoton excess

“…Another implication of the new heavy quarks is that since S-boson is a real scalar [17][18][19][20][21][22][23][24][25][26][27][28][29], below the mass of M χ there can appear an effective gauge-invariant SM operator SB µν B µν with B µ the hypercharge gauge boson (in contrast to the pseudoscalar case, which instead couples to µνρσ B µν B ρσ [30][31][32][33][34][35][36][37]). This naturally implies S → γγ, ZZ, Zγ branchings that are roughly related as 1 : 0.09 : 0.6.…”