Nuclear physicists at the University of York are putting forward a new candidate for dark matter – a particle they recently discovered called the d-star hexaquark.
Up to 80% of the Universe could be dark matter, but despite many decades of study, its physical origin has remained an enigma. While it cannot be seen directly, scientists know it exists because of its interaction via gravity with visible matter like stars and planets. Dark matter is composed of particles that do not absorb, reflect or emit light.
The particle is composed of six quarks – the fundamental particles that usually combine in trios to make up protons and neutrons. Importantly, the six quarks in a d-star result in a boson particle, which means that when many d-stars are present they can combine together in very different ways to the protons and neutrons.
The research group at York suggests that in the conditions shortly after the Big Bang, many d-star hexaquarks could have grouped together as the universe cooled and expanded to form the fifth state of matter – Bose-Einstein condensate.
Dr MIkhail Bashkanov and Professor Daniel Watts from the department of physics at the University of York recently published the first assessment of the viability of this new dark matter candidate.
Professor Daniel Watts from the department of physics at the University of York said: “The origin of dark matter in the universe is one of the biggest questions in science and one that, until now, has drawn a blank.
“Our first calculations indicate that condensates of d-stars are a feasible new candidate for dark matter and this new possibility seems worthy of further, more detailed investigation.
Co-author of the paper, Dr Mikhail Bashkanov from the Department of Physics at the University of York said: “The next step to establish this new dark matter candidate will be to obtain a better understanding of how the d-stars interact – when do they attract and when do they repel each other. We are leading new measurements to create d-stars inside an atomic nucleus and see if their properties are different to when they are in free space. ”
The researchers will now collaborate with scientists in Germany and the US to test their theory of dark matter and search for d-star hexaquarks in the cosmos.
Despite many decades of study the physical origin of ‘dark matter’ (DM) in the Universe remains elusive. In this letter we calculate the properties of a completely new DM candidate—Bose–Einstein condensates formed from a recently discovered bosonic particle in the light-quark sector, the hexaquark. In this first study, we show stable Bose–Einstein condensates could form in the primordial early universe, with a production rate sufficiently large that they are a plausible new candidate for DM. Some possible astronomical signatures of such DM are also presented.
SOURCES- University of York, Journal of Physics G: Nuclear and Particle Physics
Written By Brian Wang, Nextbigfuture.com