Great balls of Power
The potential of Q-balls puts nuclear fusion in the shade
AN UNLIMITED source of energy may one day be available if physicists can make tiny clumps of particles called Q-balls, say physicists at CERN, the European centre for particle physics near Geneva. The exotic Q-balls would also make it possible to explore a new world of physics.
Q-balls are a consequence of the theory of supersymmetry, which would help to unify all the forces in nature. The theory requires each particle of matter we know of to have an as yet undetected partner, with quarks teamed up with "squarks" and electrons paired with "selectrons", for instance
Forces between supersymmetric parti cle would glue them together in much the same way that quarks are glued together to produce the protons and neutrons that make up atomic nuclei. "Instead of an atomic nucleus, however, the result is a Q-ball," says Alex Kusenko of CERN. With his colleagues, he has calculated some of the strange physical properties of Q-balls.
In the familiar world, matter groups neatly into small particles, like protons and atoms, to obey the laws of quantum mechanics. These say that normal particles, which have an intrinsic angular momen tum, cannot exist in a single quantum state. But because supersymmetric particles carry zero spin, it tums out that this rule no longer holds. "There is no limit to the size of a Q-ball-it can be as small as a nucleus or as big as a star," says Kusenko.
More importantly, Kusenko says that inside the supersymmetric clump, the various forces would be entirely different from those in our Universe. "A Q-ball is essentially a new universe in a nutshell," says Kusenko. "Inside, forces like the strong nuclear force may be tumed off and new forces that are not evident in our Universe turned on." The bigger the Q-ball he says, the more the laws of physics within it will diverge from those we know.
Kusenko's team proposes exploring ultra high-energy physics by feeding normal particles into a Q-ball where the laws of physics could be similar to those in the energetic early Universe. Firing normal particles into a 1-gram Q-ball made of squarks and selectrons could reveal physics at energies of about 100 million giga electronvolts, 100000 times what is currently achievable, they say. They have submitted their theory to the journal Physical Review B.
Q-balls could also have far-reaching practical applications. "They could be used to provide an inexhaustible soucce of cheap energy," says Kusenko. He envisages squirting protons- which normally do not decay- into a Q-ball. "Alrnost any new physics imaginable causes proton decay," says Kusenko. "Such decays unleash the tremendous energy binding the quarks together-weight for weight, almost a hundred times the energy liberated by a hydrogen bomb."
He suggests the energy could be extracted by placing the Q-ball in water, so that proton decay fragments- electrons and photons-emerging from the ball would heat the water.
All this assumes of course that super-symmetric particles exist. Whether
they do or not may become clear when the next generation of particle accelerators
is running. Even if they do, the idea may be impractical, Kusenko admits.
"We might be able to create supersymmetric particles but still face technical
problems in fabricating Q-balls."