Search for Neutron Electric Charge at the HIBEAM Beamline at the ESS

Sammanfattning

The Standard Model does not predict the quantization of electric charge, and thus does not explicitly demand the electric neutrality of the neutron. This charge has previously been measured to an upper limit of ∼ 1 × 10^−21 elementary charges in a 1988 joint experiment between the University of Bayreuth and Institut Laue-Langevin [1]. A new experiment proposed for the HIBEAM beamline at the ESS is expected to further lower this limit by two orders of magnitude. This paper investigates the feasibility of such an experiment by simulating a realistic scenario in McStas 3.5.32. In the model, cold neutrons are deflected by a series of achromatic neutron mirrors and sent through a strong electric field over a flight path of 36.5 m. Simulation results suggest that the experiment will be able to achieve a new charge limit of (7.64 ± 0.08) × 10^−24 q_e when operating at 2 MW, which represents a 130 times increase in sensitivity from the previous result. Increasing the power to 5 MW would further lower the limit to (4.81 ± 0.05) × 10^−24 q_e, which represents a 210 times increase in sensitivity.