Speaker
Description
We describe how to optimize ion traps to function as direct detectors of millicharged particles. Although new particles with electric charge O(1) are heavily constrained, particles with lower charges are much less tightly constrained. These millicharged particles could have charges from about 0.1 down to 10^{-6} and can exist over a wide range of masses, starting at about 10 MeV. Few experiments exist which are capable of directly detecting millicharges over much of this parameter space. We detail how to use ion traps as quantum detectors with extremely low energy thresholds and suppressed standard model backgrounds. The quantum level (cyclotron mode) of the trapped ion can be read out quickly and non-destructively and used to look for interactions between the trapped ion and a single scattering millicharge. Looking for jumps of multiple cyclotron levels reduces the background while allowing us to increase the sensitivity of the trap by multiple orders of magnitude. This gives an experimental design which will be newly sensitive to particles across a wide range of masses and charges. In a section of this parameter space, the particles would constitute an irreducible signal population, produced from cosmic rays in Earth’s atmosphere.