${{\boldsymbol \Sigma}}$ 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