In early 1920s, in an effort to unify the forces of gravity and electromagnetism, Theodor Kaluza and Oskar Klein speculated about the existence of an additional dimension beyond the familiar three space dimensions and time — which in physics are combined into 4-dimensional spacetime. If it exists, such a replacement dimension would need to be incredible tiny and unnoticeable to the human eye. within the late 1990s this concept has seen an interesting renaissance, when it had been realized that the existence of a fifth dimension could resolve a number of the profound open questions of high-energy physics . especially , Yuval Grossman of Stanford University and Matthias Neubert, then a professor at Cornell University , showed during a highly cited publication that the embedding of the quality Model of high-energy physics during a 5-dimensional spacetime could explain the thus far mysterious patterns seen within the masses of elementary particles.
Another 20 years later, the group of Matthias Neubert — since 2006 on the school of Gutenberg University in Mainz (Germany) and spokesperson of the PRISMA+ Cluster of Excellence — made another unexpected discovery: they found that the 5-dimensional field equations predicted the existence of a replacement , baryon with similar properties because the famous Higgs boson but a way heavier mass — so heavy, in fact, that it can’t be produced even at the highest-energy particle collider within the world: the massive Hadron Collider (LHC) at the ecu Center for Nuclear Research CERN near Geneva (Switzerland). “It was a nightmare,” recalls Javier Castellano Ruiz, a PhD student involved within the research, “we were excited by the thought that our theory predicts a replacement particle, but it seemed to be impossible to verify this prediction in any foreseeable experiment.”
The detour through the fifth dimension
In a recent paper published within the European Physical Journal C, the researchers found a spectacular resolution to the present dilemma. they found that their proposed particle would necessarily mediate a replacement force between the known elementary particles (our visible universe) and therefore the mysterious substance (the dark sector). Even the abundance of substance within the cosmos, as observed in astrophysical experiments, are often explained by their theory. This offers exciting new ways to look for the constituents of the substance — literally via a detour through the additional dimension — and acquire clues about the physics at a really early stage within the history of our universe, when the substance was produced. “After years of checking out possible confirmations of our theoretical predictions, we are now confident that the mechanism we’ve discovered would make the substance accessible to forthcoming experiments, because the properties of the new interaction between ordinary matter and substance — which is mediated by our proposed particle — are often calculated accurately within our theory” says Matthias Neubert, head of the research team. “In the top — so our hope — the new particle could also be discovered first through its interactions with the dark sector.” this instance nicely illustrates the fruitful interplay between experimental and theoretical basic science — an indicator of the PRISMA+ Cluster of Excellence.
Adrian Carmona, Javier Castellano Ruiz, Matthias Neubert. A warped scalar portal to fermionic dark matter. The European Physical Journal C, 2021; 81 (1) DOI: 10.1140/epjc/s10052-021-08851-0