Muon source from positron on target (LEMMA)

Recently alternative schemes to produce muon beams using positrons of about 45~GeV interacting on electrons in target have been studied. The production through the process $e^+e^-\to \mu^+\mu^-$ allows very low emittance beams with no needs of cooling. A short review of the studies for a positron driven muon source, known as the Low EMittance Muon Accelerator (LEMMA) concept, will be presented and preliminary performances of the $\mu^+\mu^-$ source will be described.