# ${{\boldsymbol \Sigma}^{0}}$ MEAN LIFE INSPIRE search

These lifetimes are deduced from measurements of the cross sections for the Primakoff process ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit \Sigma}^{0}}$ in nuclear Coulomb fields. An alternative expression of the same information is the ${{\mathit \Sigma}^{0}}-{{\mathit \Lambda}}$ transition magnetic moment given in the following section. The relation is (${\mathit \mu}_{\mathrm { {{\mathit \Sigma}} {{\mathit \Lambda}} }}/{\mathit \mu}_{{{\mathit N}}}){}^{2}$ $\tau$ = $1.92951 \times 10^{-19}$ s (see DEVLIN 1986 ).
VALUE ($10^{-20}$ s) DOCUMENT ID TECN  COMMENT
$\bf{ 7.4 \pm0.7}$ OUR EVALUATION  Using ${\mathit \mu}_{\mathrm { {{\mathit \Sigma}} {{\mathit \Lambda}} }}$ (see the above note).
$6.5$ ${}^{+1.7}_{-1.1}$ 1
 1986
SPEC Primakoff effect
$7.6$ $\pm0.5$ $\pm0.7$ 2
 1986
SPEC Primakoff effect
• • • We do not use the following data for averages, fits, limits, etc. • • •
$5.8$ $\pm1.3$ 1
 1977
SPEC See DEVLIN 1986
1  DEVLIN 1986 is a recalculation of the results of DYDAK 1977 removing a numerical approximation made in that work.
2  An additional uncertainty of the Primakoff formalism is estimated to be $<$ 5$\%$.
References:
 DEVLIN 1986
PR D34 1626 On Primakoff Production of ${{\mathit \Sigma}^{0}}$ Hyperons
 PETERSEN 1986
PRL 57 949 Measurement of the ${{\mathit \Sigma}^{0}}{{\mathit \Lambda}}$ Transition Magnetic Moment
 DYDAK 1977
NP B118 1 Measurement of the ${{\mathit \Sigma}^{0}}$ Lifetime