Quarks’ constituent particles may comprise Universe’s mysterious dark matterDecember 1st, 2007 - 4:48 pm ICT by admin
London, Dec 1 (ANI): Scientists have come up with a new theory suggesting that hypothetical particles known as preons might account for a significant proportion of the mysterious dark matter that makes up a big chunk of the tangible mass of the Universe.
Preons are supposed to be the constituent particles of quarks, which are themselves the basic particles for the formation of atoms.
According to the theory formulated by Fredrik Sandin and Johan Hansson of Lulea University of Technology in Sweden, these particles might exist in super-dense chunks left over from the beginning of the Universe, and not from collapsed stars.
As the newborn Universe expanded, the matter it contained gradually thinned out, switching from preon matter to quark matter and eventually to the atoms that now make up stars and interstellar gas.
As for the formation of dark matter in the Universe, preons might provide the answer because of their supposed ability to bend light that passes by. This effect is called gravitational lensing, in which the objects acts as a kind of lens for the light of more distant stars that lie behind it when viewed from Earth.
Though gravitational lensing is well known for visible light bent by large, dark objects, the researchers say that, because preon nuggets are so small, they would exert their strongest influence on ?-rays, such as those emitted from extremely violent cosmic outbursts called ?-ray bursts. The preon lenses wouldn’t then brighten the ?-ray signal, as a normal gravitational lens does, but would produce a characteristic wobble in the spectra, thus resulting in the formation of dark matter.
“It’s not a completely daft idea”, said John Charap, a theoretical physicist at Queen Mary College in London. “And after all, we need some pretty daft ideas to make any progress in understanding dark matter. We’re currently floundering around looking for ways to explain it. This might be as good a candidate as any,” he added.
Though objects like Preons might be scattered sparsely through space and would be too small to see directly, the researchers say that there are various ways they might reveal themselves.
For example, an approach involves spotting two preon nuggets bound in mutual orbit by gravity. Such ‘binaries’ would emit gravity waves ? ripples in space-time, which could be detected with gravity-wave detectors if the binary is near the Sun.
Also, tiny preon nuggets that collide with Earth would excite seismic waves that can be identified by seismic detectors.
“They’re so small, they would just drill a hole through the planet”, Nature News quoted Hansson as saying. “But they would leave a trail of seismic waves along their path, which, being a straight line, would clearly differ from the rumbles created by the grinding of continents,” he added. (ANI)
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