PDF《CP3-Origins-2017-008 DNRF90》

246 GeV and ξ ≤ 0.12, e.g. [4]), is a measure of the misalignment of the new strong sector and the Higgs sector vacuum. Low energy scenarios based on this symmetry breaking pattern have been scrutinised in the literature in detail [5C8], however, no UV complete realisation of this minimal scenario has been established so far (see e.g. Ref. [9] for related work in the holographic context). Recently Ferretti, in Ref. [10], proposed a UV complete model based on a SU(4) (hypercolor) gauge symmetry with a ?avour structure motivated by partial composite- ness, gauge anomaly cancellation and asymptotic free- arXiv:1703.06064v2 [hep-ph]

28 Aug

2017 2 dom [11]. Earlier UV-complete realisations of the (par- tial) composite Higgs scenarios are based on embedding e?ective four fermion operators into gauge theory [12] or non-negligible irrelevant operators of SM and composite fermions [13]. This model is distinct, and non-minimal, as compared to MCHM4/5 in that the ?avour structure predicts a number of extra pseudo NGBs (PNGB). In this work we re?ect on the potential impact of lattice studies on the Higgs sector (e.g. Higgs potential, mass spectrum, . . . ) and investigate the LHC phenomenology of the exotic extra PNGBs. The combined analyses of Higgs measurements and LHC constraints on exotics allows us to identify a region of parameter space of the model, which can be cross checked against lattice calculations. This provides an important guideline for future e?orts to construct, modify, simulate and validate UV-complete models of Higgs compositeness. Pioneering lattice stud- ies [14, 15] have shown that these simulations are com- putationally demanding, therefore strengthening the case for a detailed understanding of the lattice measurements that will be relevant for phenomenology. This work is organised as follows: In Sec. II we brie?y summarise the model of [10] to make this work self- contained. The relevant low energy constants (LECs) which can be computed on the lattice are discussed and identi?ed. Subsequently, in Sec. III we study the model with available LHC Higgs measurements, for which pre- liminary results have been presented in [16], and include constraints from searches for predicted exotic states, which have so far not been discussed in the literature. We summarise and conclude in Sec. IV. II. FERRETTI'

S MODEL Ferretti'

s model [10] is a gauge theory with hypercolour gauge group GHC = SU(4) with

5 massless Weyl fermions transforming in the two-index antisymmetric representa- tion of GHC, and

3 massless Dirac fermions in the fun- damental representation of color. Using Weyl fermions, we denote these fermions ψ, χ, ? χ respectively, with ψ ∈

6 and χ ∈ 4, ? χ ∈ ?

4 under GHC. The theory has a global symmetry group GF = SU(5) * SU(3) * SU(3) * U(1)X * U(1) . (II.1) The strong dynamics of GHC is expected to break the global ?avour symmetries SU(5) → SO(5) and SU(3) * SU(3) → SU(3)c, as well as U(1)X.? The maximally at- tractive channel hypothesi........