Possibility to make a beam of tau-leptons and charmed particles by a channeling crystal

英文摘要：

We suggest a way to capture by a focusing crystal the short-lived particles (tau leptons, charmed baryons) produced in the decays downstream of a target hit by primary protons. The beam of captured short-lived particles can be extracted from the debris produced in the target and bent onto experimental setup over a distance of centimetres. The debris is rejected by the crystal, i.e. it remains nonchannelled. The technique can handle the particles with decay length cτ down to 1 micron.