Glueball dark matter, precisely (2306.09510v2)

Abstract: We delve deeper into the potential composition of dark matter as stable scalar glueballs from a confining dark $SU(N)$ gauge theory, focusing on $N={3,4,5}$. To predict the relic abundance of glueballs for the various gauge groups and scenarios of thermalization of the dark gluon gas, we employ a thermal effective theory that accounts for the strong-coupling dynamics in agreement with lattice simulations. We compare our methodology with previous works and discuss the possible sources of discrepancy. The results are encouraging and show that glueballs can account for the totality of dark matter in many unconstrained scenarios with a phase transition scale $20$ MeV$\lesssim\Lambda\lesssim10^{10}$ GeV, thus opening the possibility of exciting future studies.

• The paper presents a theoretical framework to precisely calculate the relic abundance of glueball dark matter originating from dark SU(N) gauge theories.
• It utilizes an effective field theory approach with a Polyakov loop potential to model the confining dark sector dynamics and phase transition.
• The study refines previous models by including various interaction terms and energy dissipation effects, providing more reliable relic density estimates and exploring cosmological scenarios.

Theoretical Investigations of Glueball Dark Matter in a Confining Dark SU(N) Gauge Theory

The exploration of dark matter (DM) candidates continues as a pivotal area of inquiry in astroparticle physics. This paper casts light on the potentiality of glueball dark matter, presenting a theoretically detailed investigation predicated on dark sectors characterized by an $SU(N)$ gauge theory. The authors focus on stable scalar glueballs materializing from non-abelian gauge groups with $N$ summoning values of $\{3,4,5\}$ and explore their role in accounting for the observed DM in the Universe.

Main Contributions

1. Glueball Relic Abundance Calculation: The paper develops a theoretical framework to calculate the relic abundance of these glueballs, derived from a rich, non-perturbative regime of a thermal effective field theory. By leveraging strong-coupling dynamics, in alignment with lattice simulations, the authors delineate the potential scenarios under which glueballs could constitute all observed DM. The phase transition scale in these models is calculated over a broad interval from $20~\MeV$ to $10^{10}~\GeV$.
2. Effective Potential Model: Utilizing an effective field theory approach, this paper models the confining dark sector by introducing a canonical scalar field representation for glueballs and exploiting the Polyakov loop potential to simulate the dynamics of dark gluons and glueballs. The potential $V[\phi,T]$ temperature evolution is numerically solved, revealing how glueballs undergo a phase transition to behave as cold dark matter subsequent to the confining transition.
3. Comparison and Theoretical Implications: The paper offers an intensive comparison with prior work, identifying discrepancies due to different assumptions and approximations embraced in existing literature. Specifically, formerly overlooked effects such as the inclusion of various interaction terms $n\to m$ within the glueball potential and energy dissipation through bubble nucleation are considered, thereby yielding a more reliable relic density estimation. The model's self-consistency is emphasized by examining the effect of interactions such as $\phi^3$, $\phi^4$, and $\phi^5$ within the glueball dynamics, exceeding prior analysis based primarily on $\phi^5$ interactions.
4. Cosmological Scenarios: The paper explores plausible cosmological scenarios over which the dark sector's thermal properties evolve. Models considered include freeze-out and parent particle decay scenarios, providing a comprehensive view of potential dark and visible sector interactions. Key constraints such as those from $\Delta N_{\rm eff}$ and self-interaction limits are discussed, highlighting temperature ratios where glueballs effectively account for all DM.

Implications and Speculations

This work extends the application of non-Abelian gauge theories to dark matter studies, suggesting a distinct avenue for understanding the composition and evolution of the Universe's dark sector. As cosmological precision improves and constraints on models become tighter, insights provided by glueball dynamics may reveal pivotal interactions and energy scales not yet fully recognized in current astrophysical datasets. The proposed computations and highlighted scenarios pave the way for future investigations, potentially uniting lattice QCD, cosmology, and observational astroparticle physics in pursuit of identifying viable dark matter candidates.

While much of the work remains theoretically speculative, it provides a rigorous framework upon which empirical and experimental strategies can be built. Continued cross-discipline synergy will be vital as these theoretical constructs are further refined with forthcoming observational data from sources such as galaxy surveys, cosmic microwave background analyses, and collider experiments. The theoretical foundation laid here could potentially inform direct detection strategies or accelerator-based searches as our experimental reach extends to proffer tighter constraints or possible signals of such non-standard DM candidates.