|
Astro
aktuell bei MM-Physik |
|
Astro
aktuell bei MM-Physik |
THE BLACK HOLE OF GENEVA The American Institute of Physics Bulletin of Physics News September 26, 2001 by Phillip F. Schewe, Ben Stein, and James Riordon
| .Black holes are known as the omnivorous
destroyers of stars. In reality black holes not only take
but give. Near their event horizons, where space is so
drastically warped, black holes spawn
particle-antiparticle pairs out of sheer vacuum. In some
cases one of the pair escapes beyond the horizon while
its counterpart is pulled back into the hole. Thus black
holes can shed energy in the form of this "Hawking
radiation." Physicists hope to bring this whole
process down to earth by manufacturing tiny black holes
amid the stupendous smashups of protons at the Large
Hadron Collider (LHC) being built at CERN. Until recently
theorists thought gravity was so weak compared to the
other forces that it, and gravitationally bound objects
like black holes, could be studied on an equal footing
with the other forces like the strong nuclear force only
at energies of 10^19 GeV. In the past few years, though,
some models featuring extra spatial dimensions hint that
the unification of the forces, including gravity, might
set in at much more modest energies, even in the TeV
realm of the LHC. Thus one can contemplate forming a TeV-
mass black hole even as one can imagine creating new
particles in that mass range. But what would a black hole
look like? Savas Dimopoulous of Stanford (650-723-4231)
and Greg Landsberg of Brown University
(landsberg@hep.brown.edu, 401-863-1464) have drawn a
picture in which proton-proton collisions could create
black holes with a cross section (likelihood of creation)
only about a factor of ten less than for producing top
quarks and at a rate of up to one per second (see figure
at http://www.aip.org/mgr/png ). A black hole produced in this way would
quickly decay, not in the usual particle way but in a
furious burst of Hawking radiation. A particularly
striking signature of the black hole would involve an
electron, muon, and photon in the final state of debris
particles. Properties of Hawking radiation could tell
physicists about the shape of extra spatial dimensions. A
possibility of recreating the early moments of the
universe in the lab would further unite particle physics
and cosmology (Physical Review Letters, 15 October 2001; text at http://www.aip.org/physnews/select ) |
