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${{\mathit \Sigma}}$ BARYONS ($\mathit S$ = $-1$, $\mathit I$ = 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

${{\boldsymbol \Sigma}{(1620)}}$ $I(J^P)$ = $1(1/2^{-})$

The ${\mathit S}_{\mathrm 11}$ state at 1697 MeV reported by VANHORN 1975 is tentatively listed under the ${{\mathit \Sigma}{(1750)}}$. CARROLL 1976 sees two bumps in the isospin-$1{}^{}{}^{}$ total cross section near this mass. GAO 2012 sees no evidence for this resonance. Production experiments are listed separately in the next entry.

${{\boldsymbol \Sigma}{(1620)}}$ POLE POSITION

REAL PART   $1680 \pm8$ MeV

$-2{\times }$IMAGINARY PART   $39 \pm11$ MeV

${{\boldsymbol \Sigma}{(1620)}}$ POLE RESIDUE

Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1620)}}$ $\rightarrow$ ${{\mathit \Sigma}}{{\mathit \pi}}$   $0.14 \pm0.03$

Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1620)}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \pi}}$   $0.10 \pm0.03$

Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1620)}}$ $\rightarrow$ ${{\mathit \Xi}}{{\mathit K}}$   $0.02 \pm0.01$

Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1620)}}$ $\rightarrow$ ${{\mathit \Lambda}{(1520)}}{{\mathit \pi}}$   $0.12 \pm0.05$

Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1620)}}$ $\rightarrow$ ${{\mathit \Sigma}{(1385)}}{{\mathit \pi}}$   $0.015 \pm0.010$

Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1620)}}$ $\rightarrow$ ${{\mathit N}}{{\overline{\mathit K}}^{*}{(892)}}$ , ${\mathit S}{\mathrm -wave}$   $0.05 \pm0.04$

Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1620)}}$ $\rightarrow$ ${{\mathit N}}{{\overline{\mathit K}}^{*}{(892)}}$ , ${\mathit D}{\mathrm -wave}$   $0.01 \pm0.01$

Normalized residue in ${{\mathit N}}$ ${{\overline{\mathit K}}}$ $\rightarrow$ ${{\mathit \Sigma}{(1620)}}$ $\rightarrow$ ${{\mathit N}}{{\overline{\mathit K}}}$   $0.11 \pm0.03$

${{\mathit \Sigma}{(1620)}}$ MASS   $1600\text{ to }1650\text{ }(\approx1620) $ MeV

${{\mathit \Sigma}{(1620)}}$ WIDTH   $40\text{ to }100\text{ }(\approx70) $ MeV

${{\boldsymbol \Sigma}{(1620)}}$ Decay Modes
Mode   Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/ Conf. Level P(MeV/c) $\Gamma_{1}$ ${{\mathit N}}{{\overline{\mathit K}}}$   0.10 to 0.60 364   $\Gamma_{2}$ ${{\mathit \Lambda}}{{\mathit \pi}}$   $(9.0\pm{3.0})\%$ 410   $\Gamma_{3}$ ${{\mathit \Sigma}}{{\mathit \pi}}$   $(17\pm{5})\%$ 354   $\Gamma_{4}$ ${{\mathit \Xi}}{{\mathit K}}$   -1   $\Gamma_{5}$ ${{\mathit \Lambda}{(1520)}}{{\mathit \pi}}$   $(10\pm{5})\%$ -1   $\Gamma_{6}$ ${{\mathit \Sigma}{(1385)}}{{\mathit \pi}}$   181
FOOTNOTES