Test of weak equivalence principle with antimatter

• Applicant: Professor Dr. Markus Kurt Oberthaler
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2013 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 234920277

• Final Report Year: 2019

Final Report Abstract

It is a very well experimentally tested fact that matter is accelerated by the earth’s mass independent of its decomposition – this is known as the weak equivalence principle. So far there is no direct test that this also holds for anti-matter. Thus it is an experimental challenge to confirm the weak equivalence principle explicitly and directly. Since anti-matter can only be produced at CERN it is the goal of different collaborations to reach this goal. The collaboration AEgIS is pursuing the goal by realizing a beam of anti-hydrogen at low energies but also implies that deviations from straight flight due to gravity are only few tens of micrometer. Within this project we have investigated the potential of a device developed in the context of quantum atom optics – a moiré deflectometer – for detecting these small changes in position. In this project we successfully demonstrated the moiré deflectometer for anti-protons. An important result in preparation for the realization of anti-hydrogen. The results have been published in Nature Communications. This setup has been further improved protons leading to a sensitive device for detecting electric fields as low as 22 µV/V/√Hz. The test of gravitational acceleration of anti-hydrogen is still pending mainly due to the lack of an intensive anti-hydrogen source. Currently no anti-hydrogen can be produced due to a two-year shutdown.

Publications

• A moiré deflectometer for antimatter. Nat. Commun., 2014, Vol. 5, 4538
  S. Aghion, …, P. Bräunig, …, M. K. Oberthaler, … (AEgIS collaboration)
  
• Probing electric and magnetic fields with a moiré deflectometer. Nuclear instruments and methods in physics research A, 2017, Vol. 862 49
  P. Lansonneur, P. Bräunig, A. Demetrio , S.R. Müller, P. Nedelec, M.K. Oberthaler
  
• Progress toward a large-scale ion Talbot-Lau interferometer. Physical Review A, 2017, Vol. 96, 063604
  A. Demetrio, S. R. Müller, P. Lansonneur, M. K. Oberthaler