Partially composite dark matter

Masaki Asano,Ryuichiro Kitano

doi:10.1007/jhep09(2014)171

Abstract

In a class of theories where the Higgs field emerges as a pseudo Nambu-Goldstone boson, it is often assumed that interactions to generate the top Yukawa coupling provide the Higgs potential as well. Such a scenario generically requires a little cancellation in the leading contribution to the Higgs potential, and the electroweak scale is generated by the balance between the leading and the subleading contributions. We, instead, consider the possibility that the contribution from the dark matter particle balances against that from the top quark. The thermal relic of the new particle explains the abundance of dark matter in a consistent region of the parameter space, and the direct detection is found to be promising.

Highlights

The size of the interaction required to explain the abundance of dark matter by the thermal relic is of the order of the weak interaction, that is characterized by the Higgs VEV
We consider the possibility that dark matter is the one which is responsible for creating the potential of the Higgs field
We see that in the minimal composite Higgs model, the balance between the potentials made by the top quark and the dark matter can trigger the successful electroweak symmetry breaking while explaining the abundance of the dark matter

Summary

Higgs potential from dark matter

We introduce the dark matter field, ψS, which is a Majorana fermion and singlet under the SM gauge group. In the case where there is an effective description in terms of weakly coupled composite states, such as in a large N theory, spectral functions are approximated as collections of hadron poles: ρ4(s) = f42,iδ(s − |m4,i|2), i ρ4(s) = f42,iRe[m4,i]δ(s − |m4,i|2), i ρ4,5(s) = f42,iIm[m4,i]δ(s − |m4,i|2), i ρ1(s) = f12,iδ(s − |m1,i|2), i ρ1(s) = f12,iRe[m1,i]δ(s − |m1,i|2), i ρ1,5(s) = f12,iIm[m1,i]δ(s − |m1,i|2). We assume that SO(5) symmetry is broken by a VEV of some composite operator, X, with the mass dimension d It contributes to Π4(q) − Π1(q) as ∝ X†X /q2d−1 for a large q. This condition gives the Weinberg sum rules for the spectral functions:. We assume β > 0 which is necessary for the vacuum to be stable

Electroweak symmetry breaking

Dark matter abundance and prospects for direct detection

Relic abundance

Summary