November 28, 2011 In 2008, the European-Russian satellite PAMELA
scanned the cosmic ray spectrum and picked up something curious
-- an excess of antimatter positrons. It was a startling
discovery, in part because it could have been a sign of the
existence of dark matter, long pursued by the worldwide physics
community. Now, in a paper submitted to Physical Review Letters,
and originally published on the Internet physics archive,
researchers with the Kavli Institute for Particle Astrophysics
and Cosmology (KIPAC) at Stanford University are confirming the
previous detection, and that the excess seems to grow at higher
energies in the spectrum, which is consistent with many theories
about how dark matter might produce positrons. The complete
interview with KIPAC researchers Stefan Funk and Justin
Vandenbroucke is available by clicking here The KIPAC result
comes with a major caveat, however, since those theories also
predict that the positron signal should suddenly drop-off in
cosmic rays beyond a certain energy