LOOKING FOR BLACK HOLES IN THE ATMOSPHERE is one of the prominent
missions for the newly built Pierre Auger Observatory. Black holes
can arise from the collapse of heavy stars but might also, according
to theoretical particle physics, be produced when cosmic ray
particles (especially neutrinos) with multi-TeV energies pass very
close to a particle within our atmosphere. The ensuing air shower
of secondary particles would be sensed on the ground in Auger's huge
array of detectors, which began their work in 2003 (see figure at
www.aip.org/png ). A new analysis of this hypothetical black hole
production process, however, questions whether many such
mini-black-hole events would occur. According to Dejan Stokovic
(Case Western Reserve University) and his colleagues, the same
process that encourages black hole creation in cosmic-ray neutrino
scattering events at the TeV energy level (rather than at the
impossibly inaccessible 10^19-GeV level, referred to as the Planck
energy) also should hasten the decay of protons to an extent not
seen in experiments designed to look for them. Therefore, Stokovic
(dejan@balin.phys.cwru.edu) argues, the robust stability of the
proton militates against an expected mini-black-hole production of
several hundred events over the Auger Observatory's active period
from 2003 to 2008. This doesn't necessarily mean that no black hole
events would seen, but probably not as many as were once
anticipated. (Stojkovic et al., Physical Review Letters, 3 February
2006)

***********
PHYSICS NEWS UPDATE is a digest of physics news items arising
from physics meetings, physics journals, newspapers and
magazines, and other news sources. It is provided free of charge
as a way of broadly disseminating information about physics and
physicists. For that reason, you are free to post it, if you like,
where others can read it, providing only that you credit AIP.
Physics News Update appears approximately once a week.