Composite dark matter from a model with composite Higgs boson

TL;DR

This paper embeds composite dark matter inside the minimal walking technicolor framework, proposing that most dark matter consists of techni-O-helium bound states ($tOHe$) formed when $^4He$ captures $\zeta^{--}$, yielding a warmer-than-cold DM scenario with a smaller, constrained WIMP-like component $[(UU)\zeta]$. It derives the techniparticle excess via relations between technibaryon/lepton numbers and the baryon asymmetry, and shows CDMS data force the WIMP fraction to be at most a few percent for TeV-scale masses, while BBN constraints require $m_{\zeta} \gtrsim 1\ \text{TeV}$. The work outlines a rich phenomenology: ($i$) direct-detection limits on $[(UU)\zeta]$, ($ii$) the undetectability of $tOHe$ in CDMS but possible nuclear-catalysis signals and DAMA-like ionization effects, and ($iii$) testable predictions for accelerators and cosmic rays via the doubly charged techniparticles. Overall, the model provides a self-consistent, testable pathway to composite dark matter with distinctive astrophysical and terrestrial signatures, while highlighting the need for detailed nuclear-physics studies of techni-O-helium interactions and structure formation implications.

Abstract

In a previous paper \cite{Khlopov:2007ic}, we showed how the minimal walking technicolor model (WTC) can provide a composite dark matter candidate, by forming bound states between a -2 electrically charged techniparticle and a $^4He^{++}$. We studied the properties of these \emph{techni-O-helium} $tOHe$ "atoms", which behave as warmer dark matter rather than cold. In this paper we extend our work on several different aspects. We study the possibility of a mixed scenario where both $tOHe$ and bound states between +2 and -2 electrically charged techniparticles coexist in the dark matter density. We argue that these newly proposed bound states solely made of techniparticles, although they behave as Weakly Interacting Massive Particles (WIMPs), due to their large elastic cross section with nuclei, can only account for a small percentage of the dark matter density. Therefore we conclude that within the minimal WTC, composite dark matter should be mostly composed of $tOHe$. Moreover in this paper, we put cosmological bounds in the masses of the techniparticles, if they compose the dark matter density. Finally we propose within this setup, a possible explanation of the discrepancy between the DAMA/NaI and DAMA/LIBRA findings and the negative results of CDMS and other direct dark matter searches that imply nuclear recoil measurement, which should accompany ionization.

Figures (2)

• Figure 1: : The ratio $L/B$ derived from Eq. (\ref{['dark']}). In the upper panels, $L/B$ is plotted as a function of $m_{\zeta}$, up to 2.5 TeV for the left panel and from 2.5 to 10 TeV for the right one. $x=0$ (there is no $UU\zeta$ dark matter density). The thin solid, dashed and thick solid lines correspond respectively to sphaleron freeze out temperatures of 150, 200, and 250 GeV. In the lower left panel, we plot the absolute value of $L/B$ in a logarithmic scale as a function of $m_{UU}$ if $UU\zeta$ makes up 3$\%$ of dark matter and sphaleron freeze out temperature is 250 GeV, for $m_{\zeta}=$ 2 TeV (thin solid line), 4 TeV (dashed line), and 6 TeV (thick solid line). In the lower right panel, we plot the same ratio as in the lower left panel having fixed $m_{\zeta}=4$ TeV, for three different values of $x$, $1\%$ (thin solid line), $2\%$ (dashed line), and $4\%$ (thick solid line).
• Figure 2: The upper limit of the contribution of $UU\zeta$ to the dark matter density as a function of its mass. The four lines correspond to different local dark matter densities for the Earth, namely 0.1 GeV$/{\,\rm cm}^3$ (dotted line), 0.2 GeV$/{\,\rm cm}^3$ (thick solid line), 0.3 GeV$/{\,\rm cm}^3$ (dashed line), and 0.4 GeV$/{\,\rm cm}^3$ (thin solid line).