Grand unified hidden-sector dark matter

Abstract

We explore G × G unified theories with the visible and the hidden or dark sectors paired under a Z 2 symmetry. Developing a system of 'asymmetric symmetry breaking' we motivate such models on the basis of their ability to generate dark baryons that are confined with a mass scale just above that of the proton, as motivated by asymmetric dark matter. This difference is achieved from the distinct but related confinement scales that develop in unified theories that have the two factors of G spontaneously breaking in an asymmetric manner. We show how Higgs potentials that admit different gauge group breaking chains in each sector can be constructed, and demonstrate the capacity for generating different fermion mass scales. Lastly we discuss supersymmetric extensions of such schemes.

Asymmetric dark matter and the hadronic spectra of hidden QCD

“…In such models, the Yukawa couplings of the two sectors are also independent despite the high scale mirror symmetry. This can be seen as an effect of both the different running couplings and the fact that the Higgs mechanisms responsible for mass generation in the two sectors can involve scalar states that are not mirror partners [39]. In this work we similarly take the Yukawa coupling constants of the dark quarks to be effectively unrelated to those of the corresponding ordinary quarks.…”

“…The similarity in confinement scales at low energy can be explained by models such as mirror matter [36,37] or G × G unification. Models where at high energy the gauge forces are described by a mirror symmetric SU(5) DM × SU(5) V M , can feature spontaneously broken mirror symmetry [38,39] resulting in two distinct sectors that have gauge couplings which run independently. We can then have the standard model consisting of the usual SU(3) × SU(2) × U(1), and a dark sector containing at least SU(3) D .…”

Dark matter and naturalness

“…However, a dark sector (or "hidden sector") may provide the dark matter of our universe, which will be the focus of this paper (e.g., see Refs. [3][4][5][6][7][8][9][10][11][12][13][14][15]). So could it be that the parameters of the dark sector also conspire to be fine-tuned simply for life to exist; namely that the gravitational interaction between the dark and visible sectors (or other possible weak interactions) are not too large or small as to make it difficult for galaxies, stars, etc to form?…”

Unified dark matter with intermediate symmetry breaking scales

“…2 that changes at particular mass scales allowing for the generation of different confinement scales rather than the second term in Eq. 4 at the quark mass thresholds as in [4]. In this work we will not examine any differences resulting from quark mass thresholds though of course the two effects could be utilized in a single theory.…”

“…The choice of 126 for the second is appealing as it allows the generation of fermion masses by Yukawa coupling to the 3 copies of 16 f which contain the fermions of the standard model. Since there are two multiplets required to break SO(10) to the standard model gauge group, the work of [4] can be naturally extended to SO(10) where the visible and dark sectors required two Higgs representations in each sector to carry out asymmetric symmetry breaking. By giving a non-zero VEV to all four representations in such a manner that representations paired under the Z 2 symmetry gain VEVs of different sizes, the gauge group of each sector will be different for small segments of the range between the GUT scale and the low energy theory.…”