Singlet dark matter in the SU(6)/SO(6) composite Higgs model

Haiying Cai,Giacomo Cacciapaglia

doi:10.1103/physrevd.103.055002

Abstract

Singlet scalar Dark Matter can naturally arise in composite Higgs models as an additional stable pseudo-Nambu-Goldstone boson. We study the properties of such a candidate in a model based on $SU(6)/SO(6)$, with the light quark masses generated by 4-fermion interactions. The presence of non-linearities in the couplings allows to saturate the relic density for masses $400 < m_{\rm DM} < 1000$ GeV, and survive the bound from Direct Detection and Indirect Detection. The viable parameter regions are in reach of the sensitivities of future upgrades, like XENONnT and LZ.

Highlights

The standard cosmology model, “ΛCDM” based on a flat prior, can well describe an expanding universe from the early to late times
We analyzed the properties of a pseudoscalar singlet dark matter candidate that emerges as a pseudo-Nambu-Goldstone boson from a composite Higgs model, based on the coset SU(6)/SO(6)
In particular the bottom, have to obtain their masses via an effective Yukawa operator originating from four fermion interaction, the custodial symmetry is unavoidably broken

Summary

INTRODUCTION

The standard cosmology model, “ΛCDM” based on a flat prior, can well describe an expanding universe from the early to late times. The composite nature of both DM and the Higgs boson can substantially modify the DM couplings to the SM states and alter the relative importance of various annihilation channels This is mainly due to the presence of higher order couplings, generated by nonlinearities in the pNGB couplings, which can enhance the annihilation cross sections while the coupling to the Higgs (constrained by Direct Detection) is small. The adjoint of SU(6) serves the same purpose, while the masses of the light fermions can be generated by other mechanisms This results in a violation of custodial symmetry of the order of m2b=m2h, being small enough to evade precision bounds, as we demonstrate in this paper. The small parameter space still available will be tested by the generation direct detection experiments, with DM masses in the 400 to 1000 GeV range

THE MODEL

CONCLUSION

The bottom Yukawa potential

The mass term potential