Seminarium "Teoria cząstek elementarnych i kosmologia"

We propose a neutral naturalness model based on SO(7) × SU(7) symmetry, where SU(7) ⊃ SU(3)_c x SU(3)_{\hat{c}} × U(1)_X includes the SM color group SU(3)_{c} as well as a hidden sector color group SU(3)_{\hat{c}}. The global symmetry SO(7) is spontaneously broken at scale f to SO(6) resulting in 6 Goldstone bosons including the SM Higgs doublet H and a complex scalar χ charged under SU(2)_L ⊂ SO(6) and U(1)_D ⊂ SO(6), respectively. The top-partners in our model are SM color neutral, therefore they can be lighter than a TeV and still evade all the experimental constraints. However, these top partners are electroweak charged as a result they lead to interesting signatures at the LHC. The complex scalar χ serves as a dark matter candidate where its stability is ensured by the unbroken U(1)_D symmetry and is naturally light due to the psuedo-Goldstone nature. The dark matter χ in the mass range 100-500 GeV results in correct relic abundance and satisfies the direct and indirect constraints.