Scientists Solve Dark Matter Mystery
New Model Shows Exotic Particles Create Invisible Matter
Scientists have discovered a novel explanation for the creation of the universe's mysterious dark matter.
Researchers Yu Cheng and Wei Liao explored the possibility that lighter dark matter particles could form from the decay of larger, hidden particles—akin to a cosmic game of hide-and-seek. Dark matter constitutes approximately 85 percent of the universe's matter, yet remains unseen, detectable only by its gravitational influence. This study offers insights into its elusive nature.
The team developed a theoretical model that expands upon the Standard Model of physics by introducing new particles. Their focus was on a "dark sector" comprising a scalar particle (analogous to a field that imparts mass to other particles) and a fermion (a fundamental building block of matter). They meticulously tracked the interactions and decay processes of these new particles, utilizing computer programs like MicrOmegas and CALCHEP as computational tools.
Their findings revealed a broad spectrum of possibilities for dark matter's origin. The observed cosmic abundance of dark matter could be explained if one of these new dark sector particles, designated as , possesses a mass ranging from 10 MeV (Mega-electron Volts) to 100 GeV (Giga-electron Volts). The other new dark sector particle, , could be considerably heavier, spanning the GeV to TeV (Tera-electron Volts) scale.
As the authors noted: "In this scenario, dark matter has an interaction much weaker than the weak scale interaction with the SM [Standard Model], but the dark sector still has weak scale interaction with the SM." This implies that while dark matter itself interacts minimally with ordinary matter, its companion particles within the dark sector do exhibit some interaction.
These findings are crucial for scientists actively seeking to detect dark matter. The extremely weak interaction of dark matter with everyday matter accounts for the significant challenges in its direct detection. This new understanding could significantly guide future experiments, potentially leading to the unmasking of this pervasive, invisible cosmic component.
The study incorporated certain simplifying assumptions, such as the new scalar particle decaying before a specific epoch in the early universe to prevent alterations to element formation. Future research will delve deeper into these assumptions and pursue experimental signatures of these "dark" particles.
The universe's missing mass might indeed be composed of particles resulting from the decay of slightly larger, previously hidden ones.
Reference
Yu Cheng and Wei Liao, "Light dark matter from dark sector decay," arXiv:2012.01875v2 [hep-ph] (2021).