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

${{\boldsymbol \Sigma}{(1660)}}$ $I(J^P)$ = $1(1/2^{+})$ 

For results published before 1974 (they are now obsolete), see our 1982 edition Physics Letters 111B 1 (1982).
${{\boldsymbol \Sigma}{(1660)}}$ POLE POSITION
REAL PART   $1585 \pm20$ MeV 
$-2{\times }$IMAGINARY PART   $290 {}^{+140}_{-40}$ MeV 
${{\boldsymbol \Sigma}{(1660)}}$ POLE RESIDUES
Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1660)}}$ $\rightarrow$ ${{\mathit N}}{{\overline{\mathit K}}}$   $0.07 \pm0.03$  
Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1660)}}$ $\rightarrow$ ${{\mathit \Sigma}}{{\mathit \pi}}$   $0.17 \pm0.04$  
Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1660)}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \pi}}$   $0.16 \pm0.05$  
Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1660)}}$ $\rightarrow$ ${{\mathit \Sigma}}{{\mathit \sigma}}$   $0.14 \pm0.06$  
Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1660)}}$ $\rightarrow$ ${{\mathit \Sigma}{(1385)}}{{\mathit \pi}}$
Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1660)}}$ $\rightarrow$ ${{\mathit \Lambda}{(1405)}}{{\mathit \pi}}$   $0.06 \pm0.03$  
Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1660)}}$ $\rightarrow$ ${{\mathit \Lambda}{(1520)}}{{\mathit \pi}}$   $0.04 \pm0.02$  
${{\mathit \Sigma}{(1660)}}$ MASS   $1640\text{ to }1680\text{ }(\approx1660) $ MeV 
${{\mathit \Sigma}{(1660)}}$ WIDTH   $100\text{ to }300\text{ }(\approx200) $ MeV 
$\Gamma_{1}$ ${{\mathit N}}{{\overline{\mathit K}}}$  0.05 to 010 to 0.15 405
$\Gamma_{2}$ ${{\mathit \Lambda}}{{\mathit \pi}}$  $(35\pm{12})\%$ 440
$\Gamma_{3}$ ${{\mathit \Sigma}}{{\mathit \pi}}$  $(37\pm{10})\%$ 387
$\Gamma_{4}$ ${{\mathit \Sigma}}{{\mathit \sigma}}$  $(20\pm{8})\%$
$\Gamma_{5}$ ${{\mathit \Sigma}{(1385)}}{{\mathit \pi}}$  222
$\Gamma_{6}$ ${{\mathit \Lambda}{(1405)}}{{\mathit \pi}}$  $(4.0\pm{2.0})\%$ 199
$\Gamma_{7}$ ${{\mathit \Lambda}{(1520)}}{{\mathit \pi}}$  39