# LIMIT ON ${{\boldsymbol \mu}^{-}}$ $\rightarrow$ ${{\boldsymbol e}^{-}}$ CONVERSION

Forbidden by lepton family number conservation.

# ${\boldsymbol \sigma (}$ ${{\boldsymbol \mu}^{-}}$ ${}^{}\mathrm {Ti}$ $\rightarrow$ ${{\boldsymbol e}^{-}}{}^{}\mathrm {Ti}{)}$ / ${\boldsymbol \sigma (}$ ${{\boldsymbol \mu}^{-}}$ ${}^{}\mathrm {Ti}$ $\rightarrow$ capture${)}$ INSPIRE search

VALUE CL% DOCUMENT ID TECN  COMMENT
$\bf{<4.3 \times 10^{-12}}$ 90 1
 1993
SPEC SINDRUM II
• • • We do not use the following data for averages, fits, limits, etc. • • •
$<4.6 \times 10^{-12}$ 90
 1988
TPC TRIUMF
$<1.6 \times 10^{-11}$ 90
 1985
TPC TRIUMF
1  DOHMEN 1993 assumes ${{\mathit \mu}^{-}}$ $\rightarrow$ ${{\mathit e}^{-}}$ conversion leaves the nucleus in its ground state, a process enhanced by coherence and expected to dominate.
Conservation Laws:
 LEPTON FAMILY NUMBER
References:
 DOHMEN 1993
PL B317 631 Test of Lepton-Flavour Conservation in ${{\mathit \mu}}$ $\rightarrow$ ${{\mathit e}}$ Conversion on Titanium
PRL 55 465 Search for ${{\mathit \mu}}{{\mathit e}}$ Conversion in ${}^{}\mathrm {Ti}$