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

INSPIRE search

${{\boldsymbol \Lambda}{(1520)}}$ $I(J^P)$ = $0(3/2^{-})$

Discovered by FERRO-LUZZI 1962 ; the elaboration in WATSON 1963 is the classic paper on the Breit-Wigner analysis of a multichannel resonance. The measurements of the mass, width, and elasticity published before 1975 are now obsolete and have been omitted. They were last listed in our 1982 edition Physics Letters 111B 1 (1982). Production and formation experiments agree quite well, so they are listed together here.

${{\boldsymbol \Lambda}{(1520)}}$ POLE POSITION

REAL PART

$1517\text{ to }1518\text{ }(\approx1517.5) $ MeV

$-2{\times }$IMAGINARY PART

$14\text{ to }18\text{ }(\approx16) $ MeV

${{\boldsymbol \Lambda}{(1520)}}$ POLE RESIDUES

Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Lambda}{(1520)}}$ $\rightarrow$ ${{\mathit N}}{{\overline{\mathit K}}}$

$0.45 \pm0.01$

Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Lambda}{(1520)}}$ $\rightarrow$ ${{\mathit \Sigma}}{{\mathit \pi}}$

$0.44 \pm0.01$

Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Lambda}{(1520)}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \eta}}$

$0.013 \pm0.003$