Phase transition in early universe changes strength of interaction between dark and normal matter.
Dark matter remains one of the greatest mysteries of modern physics. It is clear that it must exist, because without dark matter, for example, the motion of galaxies cannot be explained. But it has never been possible to detect dark matter in an experiment.
Currently, there are many proposals for new experiments: They aim to detect dark matter directly via its scattering from the constituents of the atomic nuclei of a detection medium, i.e., protons and neutrons.
In the HYPER model, sometime after the formation of dark matter in the early universe, the strength of its interaction with normal matter increases abruptly—which on the one hand, makes it potentially detectable today and at the same time can explain the abundance of dark matter.
The new diversity in the dark matter sector
Since the search for heavy dark matter particles, or so-called WIMPS, has not yet led to success, the research community is looking for alternative dark matter particles, especially lighter ones. At the same time, one generically expects phase transitions in the dark sector—after all, there are several in the visible sector, the researchers say. But previous studies have tended to neglect them.
“There has not been a consistent dark matter model for the mass range that some planned experiments hope to access. “However, our HYPER model illustrates that a phase transition can actually help make the dark matter more easily detectable,” said Elor, a postdoctoral researcher in theoretical physics at JGU.
The challenge for a suitable model: If dark matter interacts too strongly with normal matter, its (precisely known) amount formed in the early universe would be too small, contradicting astrophysical observations. However, if it is produced in just the right amount, the interaction would conversely be too weak to detect dark matter in present-day experiments.
“Our central idea, which underlies the HYPER model, is that the interaction changes abruptly once—so we can have the best of both worlds: the right amount of dark matter and a large interaction so we might detect it,” McGehee said.
And this is how the researchers envision it: In particle physics, an interaction is usually mediated by a specific particle, a so-called mediator—and so is the interaction of dark matter with normal matter. Both the formation of dark matter and its detection function via this mediator, with the strength of the interaction depending on its mass: The larger the mass, the weaker the interaction.
The mediator must first be heavy enough so that the correct amount of dark matter is formed and later light enough so that dark matter is detectable at all. The solution: There was a phase transition after the formation of dark matter, during which the mass of the mediator suddenly decreased.
“Thus, on the one hand, the amount of dark matter is kept constant, and on the other hand, the interaction is boosted or strengthened in such a way that dark matter should be directly detectable,” Pierce said.
New model covers almost the full parameter range of planned experiments
“The HYPER model of dark matter is able to cover almost the entire range that the new experiments make accessible,” Elor said.
Specifically, the research team first considered the maximum cross-section of the mediator-mediated interaction with the protons and neutrons of an atomic nucleus to be consistent with astrological observations and certain particle-physics decays. The next step was to consider whether there was a model for dark matter that exhibited this interaction.
“And here we came up with the idea of the phase transition,” McGehee said. “We then calculated the amount of dark matter that exists in the universe and then simulated the phase transition using our calculations.”
There are a great many constraints to consider, such as a constant amount of dark matter.
“Here, we have to systematically consider and include very many scenarios, for example, asking the question whether it is really certain that our mediator does not suddenly lead to the formation of new dark matter, which of course must not be,” Elor said. “But in the end, we were convinced that our HYPER model works.”
The research is published in the journal Physical Review Letters.

News
New material discovery could revolutionize roll-out of global vaccinations
New raw vaccine materials that could make vaccines more accessible, sustainable, and ethical have been discovered. The results of the research have been published in Polymers. Adjuvants are vaccine ingredients that boost a person's immune response [...]
Scientists Develop Incredibly Lightweight Material 4 Times Stronger Than Steel
Researchers developed a light yet strong material by combining two unexpected ingredients—DNA and glass. Working at the nanoscale provides scientists with a deep understanding and precision in crafting and analyzing materials. In broader-scale production, and even [...]
New Implant Doctors Hope Will Cut Cancer Deaths in Half
Researchers at Houston's Rice University are developing an implant that could diminish deaths caused by cancer by half. The device will contain synthetically nurtured human cells and be embedded with sensors to keep track of cancer [...]
Machine learning helps predict drugs’ favorite subcellular haunts
Most drugs are small molecules that bind firmly to a specific target—some molecule in human cells that is involved in a disease—in order to work. For example, a cancer drug's target might be a [...]
Nanotechnology Breakthrough Could Help Treat Blindness
Scientists utilize nanotechnology to address a prevalent cause of vision loss. Scientists have discovered a way to use nanotechnology to create a 3D ‘scaffold’ to grow cells from the retina. This breakthrough could lead [...]
Decoding Women’s Health: Artificial Intelligence Revolutionizes PCOS Diagnosis
NIH study reviews 25 years of data and finds AI/ML can detect common hormone disorder. Artificial intelligence (AI) and machine learning (ML) can effectively detect and diagnose Polycystic Ovary Syndrome (PCOS), which is the most common [...]
Surprising Discovery Could Explain How Coronaviruses Jump Species
New insights are enhancing scientists’ efforts to stay ahead of COVID-19 and the next pandemic. Unexpected new insights into the ways COVID-19 infects cells could shed light on the virus’s adept ability to jump from one species to another [...]
A blood test for long Covid is possible, a study suggests
Scientists can now show key differences in the blood of those who recover from Covid — and those who don't. More than three years into the pandemic, the millions of people who have suffered [...]
FedEx for your cells: this biological delivery service could treat disease
Researchers want to know why cells produce tiny packages called vesicles — and whether these bundles could be used for therapy. Graça Raposo was a young postdoc in the Netherlands in 1996 when she [...]
New study on the genetic magnetization of living bacteria shows great potential for biomedicine
Magnetic bacteria possess extraordinary capabilities due to the magnetic nanoparticles, the magnetosomes, which are concatenated inside their cells. A research team at the University of Bayreuth has now transferred all of the approximately 30 [...]
Ultrathin Nanotech Promises to Help Tackle Antibiotic Resistance
Researchers have invented a nano-thin superbug-slaying material that could one day be integrated into wound dressings and implants to prevent or heal bacterial infections. The innovation – which has undergone advanced pre-clinical trials – [...]
Researchers Discover New Mnemomic Networks in the Brain
The medial temporal lobe (MTL) houses the human memory system. Broadly, it contains the hippocampus, parahippocampal cortex, perirhinal cortex, and entorhinal cortex. “One big challenge in studying the MTL is its great anatomical variability [...]
The Surprising Origin of a Deadly Hospital Infection
C. diff might not originate from external transmission but rather from within the infected patient themselves. Hospital staff dedicate significant effort to safeguard patients from infections during their hospital stay. Through practices ranging from [...]
Google AI breakthrough – huge step in finding genes that cause diseases
Google says it has made a significant step in identifying disease-causing genes, which could help spot rare genetic disorders. A new model named AlphaMissense is able to confidently classify 89 per cent of all [...]
New Study: Everyday Pleasures Can Boost Cognitive Performance
MINDWATCH study reveals cognitive peaks with everyday pleasures. Listening to music and drinking coffee are the sorts of everyday pleasures that can impact a person’s brain activity in ways that improve cognitive performance, including [...]
Moderna reveals new highly targeted COVID-19 vaccine mRNA-1283
Moderna has developed a new and improved version of its COVID-19 vaccine. The unique formulation (mRNA-1283) reduces the vaccine's content from the full-length SARS-CoV-2 spike protein to a narrowly focused encoding of just two [...]