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arXiv · 1312.5534

Shaping the distribution of vertical velocities of antihydrogen in GBAR

Gabriel Dufour·Pascal Debu·Astrid Lambrecht·Valery Nesvizhevsky·Serge Reynaud·Alexei Voronin
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Abstract

GBAR is a project aiming at measuring the free fall acceleration of gravity for antimatter, namely antihydrogen atoms ($\overline{\mathrm{H}}$). Precision of this timing experiment depends crucially on the dispersion of initial vertical velocities of the atoms as well as on the reliable control of their distribution. We propose to use a new method for shaping the distribution of vertical velocities of $\overline{\mathrm{H}}$, which improves these factors simultaneously. The method is based on quantum reflection of elastically and specularly bouncing $\overline{\mathrm{H}}$ with small initial vertical velocity on a bottom mirror disk, and absorption of atoms with large initial vertical velocities on a top rough disk. We estimate statistical and systematic uncertainties, and show that the accuracy for measuring the free fall acceleration $\overline{g}$ of $\overline{\mathrm{H}}$ could be pushed below $10^{-3}$ under realistic experimental conditions.

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Gabriel Dufour, Pascal Debu, Astrid Lambrecht, Valery Nesvizhevsky, Serge Reynaud, Alexei Voronin. 2013-12-19. Shaping the distribution of vertical velocities of antihydrogen in GBAR. https://doi.org/10.1140/epjc%2Fs10052-014-2731-8

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