Proposed measurement of the ground-state hyperfine structure of antihydrogen

The ASACUSA collaboration at CERN-AD has recently submitted a proposal to measure the hyperfine splitting of the ground state of antihydrogen in an atomic beam line. The spectrometer will consist of two sextupoles for spin selection and analysis, and a microwave cavity to flip the spin of the antihydrogen atoms. Numerical simulations show that such an experiment is feasible if ∼200 antihydrogen atoms per second can be produced in the ground state, and that an accuracy of better than 10-7 can be reached. This measurement will be a precise test of the CPT invariance.