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
Cancer and AI – Can ChatGPT Be Trusted?
A study published in the Journal of The National Cancer Institute Cancer Spectrum delved into the increasing use of chatbots and artificial intelligence (AI) in providing cancer-related information. The researchers discovered that these digital resources accurately [...]
Breathing New Life: Oxygen Therapy Improves Heart Function in Long COVID Patients
A small trial has found that hyperbaric oxygen therapy (HBOT) may help restore proper heart function in patients with post-COVID syndrome, with participants in the HBOT group experiencing a significant increase in global longitudinal [...]
Wireless Brain-Spine Interface: A Leap Towards Reversing Paralysis
Summary: In a pioneering study, researchers designed a wireless brain-spine interface enabling a paralyzed man to walk naturally again. The ‘digital bridge’ comprises two electronic implants — one on the brain and another on the [...]
New study reveals a gel that promises to wipe out brain cancer for good
An anti-cancer gel promises to wipe out glioblastoma permanently, a feat that's never been accomplished by any drug or surgery. So what makes this gel so special? Scientists at Johns Hopkins University (JHU) have [...]
New production process for therapeutic nanovesicles
Particles known as extracellular vesicles play a vital role in communication between cells and in many cell functions. Released by cells into their environment, these “membrane particles” consist of a cellular membrane carrying a [...]
Could studying African killifish be the secret cure to sarcopenia?
The Australian Regenerative Medicine Institute (ARMI) at Monash University suggests that muscle wasting, known as sarcopenia, may be reversed in late-life The study utilized the African killifish as a model and found that muscles revert [...]
Virtual AI Radiologist: ChatGPT Passes Radiology Board Exam
The most recent version of ChatGPT, an AI chatbot developed for language interpretation and response generation, has successfully passed a radiology board-style exam, demonstrating both its potential and limitations, according to research studies published [...]
Harnessing Energy Waves: Smart Material Prototype Challenges Newton’s Laws of Motion
University of Missouri researchers designed a prototype of a small, lightweight active ‘metamaterial’ that can control the direction and intensity of energy waves. Professor Guoliang Huang of the University of Missouri has developed a [...]
Nanotechnology revolutionizes the way cancer-fighting T cells navigate and combat tumors
Vanderbilt researchers are bolstering the fight against cancer with technology that enhances the effectiveness of T cells that attack tumors. The cutting-edge research was recently published in the journal Science Immunology. Cancers co-opt both [...]
Molecular “Superpower” of Antibiotic-Resistant Bacteria Revealed in New Research
A species of ordinary gut bacteria that we all carry flourishes when the intestinal flora is knocked out by a course of antibiotics. Since the bacteria is naturally resistant to many antibiotics, it causes problems, particularly [...]
Human DNA Is All Over The Planet, And Scientists Are Worried
Every skin flake, hair follicle, eyelash, and spit drop cast from your body contains instructions written in a chemical code, one that is unique to you. According to a new study, technology has advanced [...]
Long COVID: The Invisible Consequence of Socioeconomic Inequality
A recent study conducted by the Universities of Southampton and Oxford reveals a strong correlation between the incidence of long COVID and the level of area-specific deprivation. It found that individuals from the most deprived regions are 46 [...]
Mutation Mystery: Unraveling the Secret Behind COVID-19’s Rapid Spread
Molecular modeling suggests structural consequences of an early protein mutation that promoted viral transmission. RIKEN researchers discovered that an early mutation (D614G) in the SARS-CoV-2 virus may have contributed to its rapid spread by altering the spike [...]
Protein nanoparticle vaccine with adjuvant improves immune response against influenza
A novel type of protein nanoparticle vaccine formulation containing influenza proteins and adjuvant to boost immune responses has provided complete protection against influenza viral challenges, according to a new study published by researchers in [...]
Decoding Long COVID: NIH Study Exposes the Inner Workings of Neurological Symptoms
A NIH study on twelve Long COVID patients found differences in immune cell profiles and autonomic dysfunction, contributing to the understanding of the condition and potentially leading to better diagnoses and new treatments. Twelve [...]
Pancreatic Cancer Vaccine Shows Promise in Small Trial
Using mRNA tailored to each patient’s tumor, the vaccine may have staved off the return of one of the deadliest forms of cancer in half of those who received it. Five years ago, a [...]