Asymptotically Free Natural Supersymmetric Twin Higgs Model

Abstract

Twin Higgs (TH) models explain the absence of new colored particles responsible for natural electroweak symmetry breaking (EWSB). All known ultraviolet completions of TH models require some nonperturbative dynamics below the Planck scale. We propose a supersymmetric model in which the TH mechanism is introduced by a new asymptotically free gauge interaction. The model features natural EWSB for squarks and gluino heavier than 2 TeV even if supersymmetry breaking is mediated around the Planck scale, and has interesting flavor phenomenology including the top quark decay into the Higgs boson and the up quark which may be discovered at the LHC. DOI: 10.1103/PhysRevLett.120.211803 Introduction.-Models of natural electroweak symmetry breaking (EWSB), e.g., supersymmetric (SUSY) models [1][2][3][4] and composite Higgs models [5,6], generically predict new light colored particles, called top partners, so that the quantum correction to the Higgs mass is suppressed. Null results of the LHC searches, however, show that new colored particles are heavy, which calls for fine-tuning of the parameters of the theories; this is known as the little hierarchy problem. In light of this fact the idea that the light top partners are not charged under the standard model (SM) SUð3Þ c gauge group has become increasingly attractive. Twin Higgs (TH) models [7] are one of the most studied realizations of the idea.A crucial ingredient of TH models is an approximate global SUð4Þ symmetry under which the SM Higgs boson and its mirror (or twin) partner transform as a fundamental representation. The Higgs boson is a pseudo-NambuGoldstone boson associated with the spontaneous breakdown of the SUð4Þ symmetry. The SUð4Þ symmetry of the Higgs mass term emerges from a Z 2 symmetry exchanging the SM fields with their mirror counterparts. The light top partners are then charged under the mirror gauge group rather than the SM one. Standard lore says that ultraviolet (UV) completion of TH models involves some nonperturbative dynamics. This is because the quality of the SUð4Þ

Scheme dependence of asymptotically free solutions

“…Eq. (36). For any nonvanishing C f the QFP potential behaves as a nonrational power of x at the origin; therefore, its second order derivative at x = 0 is singular for η x > 0.…”

Signatures of mirror stars

“…Such decays are not excluded by LHC data at the O(10%) level, motivating v B /v A 3 [65]. At a scale above several TeV, the model can be UV-completed in supersymmetric, extra-dimensional or composite frameworks [66][67][68][69][70][71][72][73][74][75][76]. Unfortunately, the minimal MTH theory gives rise to an unacceptable cosmological history, since the mirror and visible sectors are kept in thermal equilibrium by SM-mirror Higgs mixing until temperatures of a few GeV [55], resulting in a very large ∆N ef f = 5.7 [77,78], in conflict with current bounds [79] Fortunately, there are two simple solutions to this inconsistency, which are illustrative of the collider-cosmology complementarity of hidden sector experimental signatures.…”

Collider signals of the Mirror Twin Higgs boson through the hypercharge portal

“…It has been shown that the breaking of the discrete Z 2 symmetry can be realized spontaneously [19][20][21][22][23]. Ultraviolet completions have been constructed based on supersymmetry [24][25][26][27][28][29][30] (see also [31]), compositeness of the Higgs [32][33][34], and most recently using a "turtle" construction [35]. Composite MTH models have been shown to be consistent with precision electroweak constraints [36] and flavor bounds [37], and their collider signals studied [38,39].…”