Speaker
Description
The GBAR experiment is designed to investigate the weak equivalence principle by measuring the free-fall acceleration of antihydrogen in the Earth gravitational field [1]. The goal is to obtain a precision of 1% in a first phase, later to be improved using quantum reflection on a surface [2]. To achieve this, the first step is to produce sympathetically coolable antihydrogen ions, through two successive charge-exchange reactions:
\begin{align}
\bar{\textrm{p}} +\textrm{Ps} \rightarrow \bar{\textrm{H}} + \textrm{e}^− && (1) \newline
\bar{\textrm{H}}+\textrm{Ps} \rightarrow \bar{\textrm{H}}^+ + \textrm{e}^− && (2)
\end{align}
In this contribution, I present the first measurement of the cross-section for the production of antihydrogen using reaction (1), and our first attempts at measuring the cross-section for the matter counterpart of reaction (2).
References
[1] G. Chardin et al., “Gbar proposal to the 2011 cern spsc.” http://cds.cern.ch/record/ 1386684/files/SPSC-P-342.pdf.
[2] J. Guyomard, P. Cladé, and S. Reynaud, “Single-bounce quantum gravimeter to measure the free-fall of anti-hydrogen,” 2025.
