Birgit Henrich, Peter Fendel, Maximilian Herrmann, Jochen Walz, and Theodor W. Hänsch

Overview

A comparison between matter and antimatter atoms would offer unique possibilities to test fundamental physical theories. Especially of interest are tests of CPT symmetry and gravity. In order to accomplish this, the international ATRAP collaboration was formed in March 1997. We are part of this collaboration. The goal of ATRAP is to produce cold antihydrogen and measure its properties with high precision. Antihydrogen is highly suited for this purpose as a direct comparison can be made with normal hydrogen. Hydrogen, in turn, has been an important testing ground for fundamental theories, providing e.g. measurements of fundamental constants and highly accurate tests of quantum electrodynamics (see e.g. [1..3]).

If you wonder what antimatter is, or why it is so interesting, then read our Introduction (don't miss the annihilation animation (100k)).
In 'Antihydrogen production' and 'Antihydrogen spectroscopy' you can read about methods how to produce and measure antihydrogen.

Here at the MPQ itself the experimental effort on antihydrogen is concentrated on running and improving a light source suited for laser cooling and spectroscopy:

Laser cooling antihydrogen with 121.56 nm light

In addition we participate in the experiments going on at the Antiproton Decelerator at CERN (Geneva) where the ATRAP experiments are performed with actual antimatter (we don't have antimatter at the MPQ!). You can find a picture of the AD hall experimental areas here.

Information about the ATRAP collaboration is available at the ATRAP collaboration home page .

References:

[1] C. Schob et al., Phys. Rev. Lett. 82, 4960 (1999)
[2] A. Huber et al., Phys. Rev. Lett. 80, 468 (1990)
[3] Th. Udem et al., Phys. Rev. Lett. 79, 2646 (1997)

Kjeld Eikema 20 March 2000