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

Forbidden by total lepton number conservation.

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

VALUE CL% EVTS DOCUMENT ID TECN CHG  COMMENT
$\bf{<3.6 \times 10^{-11}}$ 90 1 1, 2
KAULARD
1998
SPEC - SINDRUM II
• • • We do not use the following data for averages, fits, limits, etc. • • •
$<1.7 \times 10^{-12}$ 90 1 3, 2
KAULARD
1998
SPEC - SINDRUM II
$<4.3 \times 10^{-12}$ 90 3
DOHMEN
1993
SPEC SINDRUM II
$<8.9 \times 10^{-11}$ 90 1
DOHMEN
1993
SPEC SINDRUM II
$<1.7 \times 10^{-10}$ 90 4
AHMAD
1988
TPC TRIUMF
1  This limit assumes a giant resonance excitation of the daughter ${}^{}\mathrm {Ca}$ nucleus (mean energy and width both 20 MeV).
2  KAULARD 1998 obtained these same limits using the unified classical analysis of FELDMAN 1998 .
3  This limit assumes the daughter ${}^{}\mathrm {Ca}$ nucleus is left in the ground state. However, the probability of this is unknown.
4  Assuming a giant-resonance-excitation model.
  Conservation Laws:
TOTAL LEPTON NUMBER
  References:
KAULARD 1998
PL B422 334 Improved Limit on the Branching Ratio of ${{\mathit \mu}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}$ Conversion on Titanium
DOHMEN 1993
PL B317 631 Test of Lepton-Flavour Conservation in ${{\mathit \mu}}$ $\rightarrow$ ${{\mathit e}}$ Conversion on Titanium
AHMAD 1988
PR D38 2102 Search for Muon Electron and Muon Positron Conversion
FELDMAN 1998
PR D57 3873 A Unified Approach to the Classical Statistical Analysis of Small Signals