${{\mathit \Lambda}}$ BARYONS
($\mathit S$ = $-1$, $\mathit I$ = 0)
${{\mathit \Lambda}^{0}}$ = ${\mathit {\mathit u}}$ ${\mathit {\mathit d}}$ ${\mathit {\mathit s}}$

${{\mathit \Lambda}}$

$I(J^P)$ = $0(1/2^{+})$ 
We have omitted some results that have been superseded by later experiments. See our earlier editions.
${{\mathit \Lambda}}$ MASS   $1115.683 \pm0.006$ MeV 
(${\mathit m}_{{{\mathit \Lambda}}}–{\mathit m}_{{{\overline{\mathit \Lambda}}}}$) $/$ ${\mathit m}_{{{\mathit \Lambda}}}$   $(-0.1 \pm1.1) \times 10^{-5}$  (S = 1.6)
${{\mathit \Lambda}}$ MEAN LIFE
Mean life $\tau $   $(2.632 \pm0.020) \times 10^{-10}$ s (S = 1.6)
(${\mathit \tau}_{{{\mathit \Lambda}}}–{\mathit \tau}_{{{\overline{\mathit \Lambda}}}}$) $/$ ${\mathit \tau}_{{{\mathit \Lambda}}}$   $-0.001 \pm0.009$  
${{\mathit \Lambda}}$ MAGNETIC MOMENT   $-0.613 \pm0.004$ $\mu _{\mathit N}$ 
${{\mathit \Lambda}}$ ELECTRIC DIPOLE MOMENT   $<1.5 \times 10^{-16}$ $\mathit e~$cm  CL=95.0%
${{\mathit \Lambda}}$ $\mathit CP$-violating decay-rate asymmetries
$\mathit A_{CP}$( ${{\mathit p}}{{\mathit \mu}^{-}}{{\overline{\mathit \nu}}_{{\mu}}}$ ) in ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \mu}^{-}}{{\overline{\mathit \nu}}_{{\mu}}}$ , ${{\overline{\mathit \Lambda}}}$ $\rightarrow$ ${{\overline{\mathit p}}}{{\mathit \mu}^{+}}{{\mathit \nu}_{{\mu}}}$   $0.02 \pm0.14$  
${{\mathit \Lambda}}$ DECAY PARAMETERS
$\alpha _{−}$ FOR ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \pi}^{-}}$   $0.748 \pm0.007$  (S = 2.1)
$\alpha _{+}$ FOR ${{\overline{\mathit \Lambda}}}$ $\rightarrow$ ${{\overline{\mathit p}}}{{\mathit \pi}^{+}}$   $-0.757 \pm0.004$  
${{\overline{\mathit \alpha}}_{{0}}}$ FOR ${{\overline{\mathit \Lambda}}}$ $\rightarrow$ ${{\overline{\mathit n}}}{{\mathit \pi}^{0}}$   $-0.692 \pm0.017$  
$\alpha _{{{\mathit \gamma}}}$ FOR ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit n}}{{\mathit \gamma}}$   $-0.16 \pm0.11$  
$\phi $ ANGLE FOR ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \pi}^{-}}$ (tan$\phi $ = $\beta $ $/$ $\gamma $)   $-6.5 \pm3.5$ $^\circ{}$ 
$\alpha _{0}$ $/$ $\alpha _{−}$ = $\alpha\mathrm {( {{\mathit \Lambda}} \rightarrow {{\mathit n}} {{\mathit \pi}^{0}} )}$ $/$ $\alpha\mathrm {( {{\mathit \Lambda}} \rightarrow {{\mathit p}} {{\mathit \pi}^{-}} )}$   $1.01 \pm0.07$  
${{\overline{\mathit \alpha}}_{{0}}}$ $/$ ${{\mathit \alpha}_{{+}}}$ in ${{\overline{\mathit \Lambda}}}$ $\rightarrow$ ${{\overline{\mathit n}}}{{\mathit \pi}^{0}}$ , ${{\overline{\mathit \Lambda}}}$ $\rightarrow$ ${{\overline{\mathit p}}}{{\mathit \pi}^{+}}$   $0.913 \pm0.030$  
(${{\mathit \alpha}_{{-}}}$ + ${{\mathit \alpha}_{{+}}})/({{\mathit \alpha}_{{-}}}−{{\mathit \alpha}_{{+}}}$) in ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \pi}^{-}}$ , ${{\overline{\mathit \Lambda}}}$ $\rightarrow$ ${{\overline{\mathit p}}}{{\mathit \pi}^{+}}$   $-0.002 \pm0.004$  
R = $\vert G_{E}/G_{M}\vert $ in ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \pi}^{-}}$ , ${{\overline{\mathit \Lambda}}}$ $\rightarrow$ ${{\overline{\mathit p}}}{{\mathit \pi}^{+}}$   $0.96 \pm0.14$  
$\Delta \Phi $ = $\Phi _{E}$ $−$ $\Phi _{M}$ in ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \pi}^{-}}$ , ${{\overline{\mathit \Lambda}}}$ $\rightarrow$ ${{\overline{\mathit p}}}{{\mathit \pi}^{+}}$   $37 \pm13$ degrees 
${\mathit g}_{{{\mathit A}}}$ $/$ ${\mathit g}_{{{\mathit V}}}$ FOR ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit p}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}_{{e}}}$   $-0.718 \pm0.015$  
$\Gamma_{1}$ ${{\mathit p}}{{\mathit \pi}^{-}}$   $(64.1\pm{0.5})\%$ 101
$\Gamma_{2}$ ${{\mathit n}}{{\mathit \pi}^{0}}$   $(35.9\pm{0.5})\%$ 104
$\Gamma_{3}$ ${{\mathit n}}{{\mathit \gamma}}$   $(8.3\pm{0.7})\times 10^{-4}$ 162
$\Gamma_{4}$ ${{\mathit p}}{{\mathit \pi}^{-}}{{\mathit \gamma}}$  [1] $(8.5\pm{1.4})\times 10^{-4}$ 101
$\Gamma_{5}$ ${{\mathit p}}{{\mathit e}^{-}}{{\overline{\mathit \nu}}_{{e}}}$   $(8.34\pm{0.14})\times 10^{-4}$ 163
$\Gamma_{6}$ ${{\mathit p}}{{\mathit \mu}^{-}}{{\overline{\mathit \nu}}_{{\mu}}}$   $(1.51\pm{0.19})\times 10^{-4}$ 131
Constrained Fit information