Dark Matter from new Technicolor Theories

TL;DR

This work evaluates dark matter candidates arising from walking technicolor theories by computing the relic density of the lightest neutral technibaryon (LTB, $DD$) under thermal equilibration, electric neutrality, and sphaleron processes, for both second- and first-order electroweak phase transitions. It derives the LTB contribution through chemical-potentials methods and mass-dependent statistical functions, linking TB/B to the DM fraction via $rac{ ho_{TB}}{ ho_B}$ and exploring how $T^*$ and phase-transition order shape the viable $m_{DD}$ range. Direct-detection implications are assessed with spin-independent scattering, using CDMS-like rates and current bounds to constrain the allowed LTB fraction of DM, yielding a TeV-scale mass window (roughly 1.4–3.3 TeV) compatible with 10–65% of the local DM density under plausible parameters. The results motivate a multi-component DM scenario, potentially including a techniaxion, and suggest that future detectors could decisively test technicolor-based DM candidates.

Abstract

We investigate dark matter candidates emerging in recently proposed technicolor theories. We determine the relic density of the lightest, neutral, stable technibaryon having imposed weak thermal equilibrium conditions and overall electric neutrality of the Universe. In addition we consider sphaleron processes that violate baryon, lepton and technibaryon number. Our analysis is performed in the case of a first order electroweak phase transition as well as a second order one. We argue that, in both cases, the new technibaryon contributes to the dark matter in the Universe. Finally we examine the problem of the constraints on these types of dark matter components from earth based experiments.

Figures (4)

• Figure 1: Plot representing the region of the parameters according to which the fraction of technibaryon matter density over the baryonic one takes on the values $[3.23,\,5.55]$. We consider a second order phase transition. The parameters in the plot are the mass of the LTB DM particle and $\xi$ of Eq. (\ref{['soxidef']}). The plot includes various values of $T^{\ast}$. The dotted line separates areas of abundant particles and anti-particles.
• Figure 2: Plot representing the region of the parameters according to which the fraction of technibaryon matter density over the baryonic one takes on the values $[3.23,\,5.55]$. Here we consider the case of a first order phase transition. The parameters in the plot are the mass of the LTB DM particle and $\xi$ of Eq. (\ref{['foxidef']}). The dotted line separates areas of abundant particles and anti-particles.
• Figure 3: Amount of LTB DM as function of the mass of the LTB particle. The plot is shown for $L'=0$ and $L=B$ for second order (SO) phase transitions with various temperatures $T^*$ and a for first order (FO) phase transition as well.
• Figure 4: Top Panel: The maximal fraction of local DM density allowed by the 90% experimental constraint as function of the local DM density and the parameter $\xi$ of Eq. (\ref{['soxidef']}). Bottom Panel: For the corresponding maximal fraction of local DM density currently allowed by the 90% experimental constraint as function of the local DM density and $\xi$ we plot the associated LTB mass. Both plots are presented with second order phase transition with $T^* = 250$ GeV and a recoil energy $T=50$ keV.