Nicolas PICOT-CLEMENTE
University of Maryland, Institute for Physical Science and Technology
Search for magnetic monopoleswith the ANTARES underwater neutrino telescope
The ANTARES underwater neutrino telescope, located in the Mediterranean Sea at a depth of 2500m, 40km off the Provencal coast, is composed by an array of 885 photomultipliers distributed on 12 vertical lines. The detector is fully operational since May 2008.
Besides the detection of neutrino-induced muons, the telescope is more generally sensitive to particles which emit Cherenkov light, and, thanks to its large volume, offers new opportunities to improve the sensitivity to exotic particles, such as magnetic monopoles.
Magnetic monopoles are stable magnetically charged particles first introduced in a consistent manner by Dirac in 1931, which showed that their own existence would give an explanation to the quantization of the electric charge. They would have been produced in the Early Universe, and would bring a first proof to the existence of grand unified models.
After having presented the ANTARES neutrino telescope and its last results, magnetic monopoles will be introduced, as well as their signal caracteristics in a neutrino telescope. Then, the analysis which uses a dedicated algorithm able to reconstruct the velocity of the incoming particles will be described.
Finally, after applying the analysis on the data taken in 2008, a new upper limit on the magnetic monopole flux is presented. It becomes the best worldwide constraint in the velocity range β=[0.625,1], and improves for the first time below the Cherenkov threshold the sensitivity obtained with a neutrino telescope.