A moiré deflectometer for antimatter

Abstract

The precise measurement of forces is one way to obtain deep insight into the fundamental interactions present in nature. In the context of neutral antimatter, the gravitational interaction is of high interest, potentially revealing new forces that violate the weak equivalence principle. Here we report on a successful extension of a tool from atom optics—the moiré deflectometer—for a measurement of the acceleration of slow antiprotons. The setup consists of two identical transmission gratings and a spatially resolving emulsion detector for antiproton annihilations. Absolute referencing of the observed antimatter pattern with a photon pattern experiencing no deflection allows the direct inference of forces present. The concept is also straightforwardly applicable to antihydrogen measurements as pursued by the AEgIS collaboration. The combination of these very different techniques from high energy and atomic physics opens a very promising route to the direct detection of the gravitational acceleration of neutral antimatter.

Efficient antihydrogen detection in antimatter physics by deep learning

“…In recent years numerous experiments have successfully trapped, or formed a beam of, antihydrogen atoms. These experiments aim to test CPT symmetry by comparing the properties of the antihydrogen atom to those of the hydrogen atom [1][2][3][4], or test the effects of gravity on antimatter [5][6][7]. Antihydrogen is produced either by injecting antiproton and positron plasmas into cryogenic electro-magnetic traps where three-body recombination takes place ( -¯) .…”

AEGIS at Cern: measuring antihydrogen fall

“…The experiment was approved in 2008 and is now in an advanced stage of construction, commissioning and preliminary test of subsystems. Preliminary measurements have been made concerning antiproton annihilation in emulsion and silicon detectors [21,22] as well as tests of the principle and resolution of the moiré deflectometer and the emulsions [23]. The next steps ahead are the spectroscopic study of Positronium, the formation of Antihydrogen and the measurement of g with 1% sensitivity.…”

Efficient 2S3 positronium production by stimulated decay from the 3PAntonello1, Belov2, Bonomi3 et al. 2019Phys. Rev. ASelf Cite10070View full textAdd to dashboardCite

“…This is due to its optical metastability: single-photon radiative decays to 1 3 S are prohibited by the electric dipole selection rules and the reduced overlap between the positron and the electron wave-functions increases its annihilation lifetime by a factor of eight [4]. On top of its high-precision spectroscopy applications, 2 3 S Ps is one of the few notable candidate systems being considered for measuring the gravitational interaction between matter and antimatter [5], together with Ps in long-lived Rydberg states [6,7], arXiv:1904.09004v1 [physics.atom-ph] 18 Apr 2019 antihydrogen [8][9][10] and muonium [11]. Moreover, the metastable 2 3 S Ps has a very low electrical polarizability, thus being scarcely sensitive to stray electric fields [12], and is a good candidate for atom interferometry, provided that a beam with sufficiently low divergence and high intensity is demonstrated [5].…”