Gauge theories of partial compositeness: scenarios for Run-II of the LHC

Abstract

We continue our investigation of gauge theories in which the Higgs boson arises as a pseudo-Nambu-Goldstone boson (pNGB) and top-partners arise as bound states of three hyperfermions. All models have additional pNGBs in their spectrum that should be accessible at LHC. We analyze the patterns of symmetry breaking and present all relevant couplings of the pNGBs with the gauge fields. We discuss how vacuum misalignment and a mass for the pNGBs is generated by a loop-induced potential. Finally, we paint a very broad, qualitative, picture of the kind of experimental signatures these models give rise to, setting the stage for further analysis.

Fundamental partial compositeness

“…In fact, by construction the new composite techni-baryons have mass dimensions close to the minimum required of 5/2. Because any purely fermionic extension [27][28][29][30] is required to have composite baryons with dimensions close to 5/2, these baryons would presumably behave as if they were made by a fermion and a composite scalar similar to ours (see also [31] for a supersymmetric realization). The technicolor group is indicated by G TC , which can be either SU(N ), SO(N ) or Sp(N ) with vectorial techni-fermions and techni-scalars.…”

“…A sizeable misalignment between H 0 and H 0 would give a contribution of order v 2 /f 2 TC such that the experimental bound |T | 2 × 10 −3 would imply 22 For N = 2 the TC gauge group is SU(2) ∼ Sp(2) and the pattern of global symmetry breaking in the fermionic sector becomes SU(8) → Sp(8) giving rise to 27 TCπ. 23 Defining the complex bidoublet M = (H , H), our parametrization is equivalent to [30], once M is identified with Φ1 + iΦ2, where Φ1,2 are two real bi-doublets of SU(2)L ⊗ SU(2)R. Moreover, we can rotate H0 and H 0 to the basis where only one doublet gets a vacuum expectation value, and our formulae take the form of section 4.2 with the physical SM-like Higgs h ≡ Re (H0 + H 0 ).…”

A UV complete compositeness scenario: LHC constraints meet the lattice

“…The NGBs fields are denoted by Π, classified according to their SU(2) L × U(1) Y quantum numbers Π = (η, H, Φ 0 , Φ) ∈ 1 0 + 2 ±1/2 + 3 0 + 3 ±1 and the 2 ±1/2 is identified as the SM Higgs doublet. In this work we investigate the phenomenology of the triplet states but ignore the NGB-singlets η mentioned above and η due to U(1) -breaking whose phenomenology has been scrutinised in [24,25].…”

“…Searches for pair-produced colour-octet scalars π a , as predicted from the breaking to QCD in eq. (2.2) SU(3) × SU(3) → SU(3) c with subsequent gauging of QCD, have been considered in theories of vector-like confinement [56][57][58], compositeness [24,[59][60][61][62], as well as in hybrid SUSY models [63,64]. Searches were performed during Run-1 [65,66] in four jet final states as well as in R-parity violating SUSY scenarios [67].…”

“…6 Again we use a combination of Feynrules [72][73][74], Ufo [75] and MadEvent [76]. 7 There is also the possibility of small anomaly-induced terms which we will not consider in this work; they are expected to be parametrically small [24]. 8 Using a modified version of Vbfnlo [86] together with FeynArts/FormCalc/LoopTools [87,88].…”