New Interpretations of Measured Antihydrogen Velocities and Field Ionization Spectra

We present extensive Monte Carlo simulations, showing that cold antihydrogen (H̅ ) atoms are produced when antiprotons (p̅ ) are gently heated in the side wells of a nested Penning trap. The observed H̅ with high energies, that had seemed to indicate otherwise, are instead explained by a surprisingly effective charge-exchange mechanism. We shed light on the previously measured field-ionization spectrum, and reproduce both the characteristic low-field power law as well as the enhanced H̅ production at higher fields. The latter feature is shown to arise from H̅ atoms too deeply bound to be described as guiding center atoms, atoms with internally chaotic motion.