A new model for dark matter

Darkish matter stays one of many best mysteries of recent physics. It’s clear that it should exist, as a result of with out darkish matter, for instance, the movement of galaxies can’t be defined. Nevertheless it has by no means been attainable to detect darkish matter in an experiment.

At present, there are various proposals for brand new experiments: They intention to detect darkish matter immediately by way of its scattering from the constituents of the atomic nuclei of a detection medium, i.e., protons and neutrons.

A group of researchers-Robert McGehee and Aaron Pierce of the College of Michigan and Gilly Elor of Johannes Gutenberg College of Mainz in Germany-has now proposed a brand new candidate for darkish matter: HYPER, or “HighlY Interactive ParticlE Relics.”

Within the HYPER mannequin, a while after the formation of darkish matter within the early universe, the power of its interplay with regular matter will increase abruptly-which on the one hand, makes it probably detectable at this time and on the similar time can clarify the abundance of darkish matter.

The brand new range in the dead of night matter sector

For the reason that seek for heavy darkish matter particles, or so-called WIMPS, has not but led to success, the analysis group is in search of various darkish matter particles, particularly lighter ones. On the similar time, one generically expects part transitions in the dead of night sector-after all, there are a number of within the seen sector, the researchers say. However earlier research have tended to neglect them.

“There has not been a constant darkish matter mannequin for the mass vary that some deliberate experiments hope to entry. “Nonetheless, our HYPER mannequin illustrates {that a} part transition can truly assist make the darkish matter extra simply detectable,” stated Elor, a postdoctoral researcher in theoretical physics at JGU.

The problem for an acceptable mannequin: If darkish matter interacts too strongly with regular matter, its (exactly identified) quantity shaped within the early universe could be too small, contradicting astrophysical observations. Nonetheless, whether it is produced in simply the correct quantity, the interplay would conversely be too weak to detect darkish matter in present-day experiments.

“Our central thought, which underlies the HYPER mannequin, is that the interplay modifications abruptly once-so we are able to have the most effective of each worlds: the correct quantity of darkish matter and a big interplay so we’d detect it,” McGehee stated.

And that is how the researchers envision it: In particle physics, an interplay is normally mediated by a selected particle, a so-called mediator-and so is the interplay of darkish matter with regular matter. Each the formation of darkish matter and its detection operate by way of this mediator, with the power of the interplay relying on its mass: The bigger the mass, the weaker the interplay.

The mediator should first be heavy sufficient in order that the correct quantity of darkish matter is shaped and later mild sufficient in order that darkish matter is detectable in any respect. The answer: There was a part transition after the formation of darkish matter, throughout which the mass of the mediator all of the sudden decreased.

“Thus, on the one hand, the quantity of darkish matter is saved fixed, and then again, the interplay is boosted or strengthened in such a approach that darkish matter needs to be immediately detectable,” Pierce stated.

New mannequin covers virtually the complete parameter vary of deliberate experiments

“The HYPER mannequin of darkish matter is ready to cowl virtually the whole vary that the brand new experiments make accessible,” Elor stated.

Particularly, the analysis group first thought-about the utmost cross part of the mediator-mediated interplay with the protons and neutrons of an atomic nucleus to be according to astrological observations and sure particle-physics decays. The following step was to contemplate whether or not there was a mannequin for darkish matter that exhibited this interplay.

“And right here we got here up with the concept of the part transition,” McGehee stated. “We then calculated the quantity of darkish matter that exists within the universe after which simulated the part transition utilizing our calculations.”

There are an awesome many constraints to contemplate, similar to a continuing quantity of darkish matter.

“Right here, now we have to systematically contemplate and embody very many situations, for instance, asking the query whether or not it’s actually sure that our mediator doesn’t all of the sudden result in the formation of latest darkish matter, which after all should not be,” Elor stated. “However in the long run, we had been satisfied that our HYPER mannequin works.”

Analysis Report:Maximizing Direct Detection with Highly Interactive Particle Relic Dark Matter

Associated Hyperlinks

University of Michigan

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LHAASO’s dark matter search places tighter constraints on dark matter’s lifetime

Daocheng, China (SPX) Jan 03, 2023


Scientists from the Giant Excessive Altitude Air Bathe Observatory (LHAASO) have introduced roughly 1.5 years of observational knowledge, calculating new limits on the lifetime of heavy darkish matter particles which have lots between 10^5 and 10^9 giga-electron volts.

The research, entitled “Constraints on heavy decaying darkish matter from 570 days of LHAASO observations,” was just lately printed as a spotlight letter in Physics Evaluate Letter.

Till now, folks have by no means stopped revealing the mysteries of d … read more