Test of lepton-flavour conservation in μ → e conversion on titanium☆

Abstract A search for μ → e conversion in muonic atoms is being performed at PSI with the SINDRUM II spectrometer. A first measurement on Ti gives upper limits on the branching ratios for the ground-state transitions of Γ(μ − Ti → e − Ti g.s. ) Γ(μ − Ti capture ) −12 and Γ(μ − Ti → e + Ca g.s. ) Γ(μ − Ti capture ) −12 (90% confidence ) . With the assumption of a giant resonance excitation of the Ca nucleaus the limit on the total rate for μ − → e + conversion is Γ(μ − Ti → e + Ca ∗ ) Γ(μ − Ti capture ) −11 .