It might be possible to use the concentration of carbon-60 molecules found in geological samples to set limits on exotic particles such as magnetic monopoles according to two physicists. Carbon-60 molecules are only found in geological samples that have been subjected to extreme conditions such as lightning strikes or meteorite impacts. Interactions with any exotic highly ionizing particles left over from the big bang might also cause carbon-60 to form according to Juan Collar of the University of Paris 7 and CERN, and Konstantin Zioutas from Thessaloniki University in Greece (Phys. Rev. Lett. 83 3097).
As the highly energetic particles pass through conventional carbon-rich rocks, they would form carbon-60 molecules in their wake. The fact that these geological detectors have been “collecting data” for millions of years, combined with the stability of carbon-60 molecules, could give this geological approach to particle physics a “winning edge” according to Collar. Another bonus is that natural radioactive processes in rocks are not energetic enough to form carbon-60 molecules.
Physicists discovered only recently that carbon-60 molecules could form under heavy Ion irradiation. Collar and Zioutas are now trying to irradiate geological samples at CERN to “calibrate” the response of these detectors. “The nice thing is that the technique can be put into practice immediately using available fullerene detection methods,” says Collar. “Its sensitivity to some exotic particles should immediately exceed existing limits – which is a hard thing to do.”
