The LAPP group has been involved in the Alpha Magnetic Spectrometer experiment from the beginning in the mid 1990s.
For AMS-01, the LAPP group designed the cells of the aerogel threshold Cherenkov counter and made an important contribution to the construction of the detector which was used to identify electrons and positrons. The group also contributed to the data analysis and published a paper on the interpretation of data.
After this precursor flight, the AMS group of LAPP participated very actively in the design, construction, and integration of the electromagnetic calorimeter of AMS-02, as well as all the phases of testing and space qualification. The group focused on measuring and monitoring the calorimeter performance on the space station and developing related analysis tools. The calorimeter is a key element of AMS since it accurately measures the energy of electrons and positrons and contributes to their identification. The group was therefore naturally devoted to the measurement of electron and positron fluxes, as well as to the measurement of antiproton flux.
All of these measurements are essential for indirect dark matter searches. By annihilating in particle-antiparticle pairs, dark matter particles could contribute to increase the proportion of positrons and antiprotons in cosmic rays. In recent years, the LAPP group has invested data analysis, studying electrons, positrons, and antiprotons. An abnormal signal from the flux measurement of these particles could sign the indirect detection of dark matter. Indeed, an excess of positrons has been observed by AMS, that could be explained either by dark matter annihilation, or by astrophysical sources such as pulsars.