Analysis of the timing of freely falling antihydrogen

We evaluate the accuracy to be expected for the measurement of free fall acceleration of antihydrogen in the GBAR experiment, accounting for the recoil transferred in the photodetachment process. We show that the uncertainty on the measurement of gravity comes mainly from the initial velocity dispersion in the ion trap so that the photodetachment recoil is not the limiting factor to the precision as a naive analysis would suggest. This result will ease the constraints on the choice of the photodetachment laser parameters.

Automated summary

We evaluated the expected accuracy of measuring the free fall acceleration of antihydrogen in the GBAR experiment, taking into account the recoil transferred in the photodetachment process. Our study reveals that the uncertainty in gravity measurement mainly arises from the initial velocity dispersion in the ion trap, indicating that the photodetachment recoil is not the limiting factor to precision as previously thought. This finding will alleviate the constraints on choosing the parameters for the photodetachment laser.