Improving the statistical analysis of antihydrogen free fall by using near-edge events

An accurate evaluation of the gravity acceleration from the timing of free fall of antihydrogen atoms in the Gravitational Behaviour of Anti-hydrogen at Rest (GBAR) experiment requires one to account for obstacles surrounding the antimatter source. These obstacles reduce the number of useful events but may improve accuracy since the edges of the shadows of obstacles on the detection chamber depend on gravity, bringing additional information about the value of g. We perform Monte Carlo simulations to obtain the dispersion and give a qualitative understanding of the results by analyzing the statistics of events close to an edge. We also study the effect of specular quantum reflections of antihydrogen on surfaces and show that they do not degrade the accuracy that much.

Automated summary

In the GBAR experiment, accurately evaluating the gravity acceleration requires considering obstacles surrounding the antimatter source. Monte Carlo simulations and analysis of event statistics near the edges of obstacles provide valuable insights into the accuracy of the evaluation. The specular quantum reflections of antihydrogen on surfaces do not affect the accuracy significantly.