The Majorana Demonstrator is an ultra low-background experiment searching for Neutrinoless double-beta decay in 76Ge. The heavily shielded array of germanium detectors, placed nearly a mile underground at the Sanford Underground Research Facility in Lead, South Dakota, also allows searches for new exotic physics. Free, relativistic, lightly-ionizing particles with electrical charges less than e are forbidden by the standard model but predicted by some of its extensions. If such particles exist, they might be detected in the Majorana Demonstrator by searching for multiple-detector events with individual-detector energy depositions down to 1 keV. This search is background free and no candidate events have been found in 285 days of data taking. New direct-detection limits are set for the flux of lightly ionizing particles for charges as low as e/1000.
Revised: June 17, 2020 |
Published: May 25, 2018
Citation
Alvis S.I., I.J. Arnquist, F.T. Avignone, A. Barabash, C.J. Barton, F. Bertrand, and V. Brudanin, et al. 2018.First Limit on the direct detection of Lightly Ionizing Particles for Electric Charge as Low as e/1000 with the MAJORANA DEMONSTRATOR.Physical Review Letters 120, no. 21:Article number 211804.PNNL-SA-132160.doi:10.1103/PhysRevLett.120.211804