LEMMA-TB: an experiment to measure the production of a low emittance muon beam

The proposed experiment aims at studying for the properties of the production of muon-antimuon pairs by means of a positron beam on target, specifically in the regime where the positron-electron energy is close to the di-muon mass threshold. The longitudinal asymmetry is such that the emerging muons result very collimated. This production mechanism is in fact proposed to yield muon beams for a high energy muon collider that do not require any cooling process (known as the LEMMA scheme). LEMMA-TB will exploit a 45 GeV positron beam provided in the North Area in a controlled, flexible and spacey environment. The physics program includes the measurement of the signal differential cross section, the emittance of the emerging muon beam and the properties of the spent positron beam. With this document, the authors seek the recommendation of the SPS and PS Experiments Com- mittee for a three week beam team in 2021.