Newly Proposed Heavy Particle Could Help Unravel Dark Matter Mysteries

Scientists from the University of Granada have proposed a new particle which, in contrast to the Higgs boson discovered in 2012 at CERN’s Large Hadron Collider after a four-decade quest, is so heavy that it is impossible to produce directly even in this collider.

The University of Granada (UGR) is one of the participants in this crucial scientific progress in Theoretical Physics, which could help resolve the mysteries of dark matter.

Researchers at UGR and the Johannes Gutenberg University Mainz (Germany) recently published a research paper where they have made attempts to extend the Standard Model of particle physics (the analog of “the periodic table” for particle physics) and find solutions to certain questions that this model cannot answer.

Following are some of the questions: What constitutes the dark matter? What is the reason behind the different masses of the various constituents of fermionic dark matter? Or, why is the force of gravity considerably weaker compared to electromagnetic interaction?

Published in the European Physical Journal C, this study is based on the occurrence of a dimension in spacetime that is “so small that we can only detect evidence of it through its indirect effects,” explained Adrián Carmona, one of the authors of the paper and Athenea3i Fellow at the UGR, who is also a member of the Department of Theoretical Physics and the Cosmos.

Back in the 1920s, Theodor Kaluza and Oskar Klein made efforts to combine the forces of electromagnetism and gravity, speculating on the occurrence of an additional dimension apart from the three familiar space dimensions and time (which, in physics, are unified into a 4-dimensional spacetime).

Models such as these gained fame in the 1990s when theoretical physicists understood that theories with curved additional dimensions could solve certain major mysteries in this field. But despite their several strengths, such models often lacked a feasible dark-matter candidate.

Over two decades later, Adrián Carmona and his collaborators from the University of Mainz, Professor Matthias Neubert, and doctoral student Javier Castellano, have now proposed the occurrence of a new heavy particle in these models with properties analogous to those of the famous Higgs boson.

A New Dimension

This particle could play a fundamental role in the generation of masses of all the particles sensitive to this extra dimension, and at the same time be the only relevant window to a possible dark sector responsible for the existence of dark matter, which would simultaneously solve two of the biggest problems of these theories that, a priori, appear disconnected.

Adrián Carmona, Athenea3i Fellow and Member, Department of Theoretical Physics and the Cosmos, University of Granada

But in contrast to the Higgs boson, the new particle is so heavy that it could not be created directly even in CERN’s Large Hadron Collider, which is the highest-energy particle collider in the whole world.

In the paper, the researchers look for other viable methods to discover this particle by searching for clues related to the physics related to a very early stage in the history of the universe, when dark matter was generated.

Journal Reference:

Carmona, A., et al. (2020) A warped scalar portal to fermionic dark matter. The European Physical Journal C. doi.org/10.1140/epjc/s10052-021-08851-0.