#### EXTRAPOLATIONS BELOW ${{\mathit N}}{{\overline{\mathit K}}}$ THRESHOLD

VALUE (MeV) DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
$\text{50.24 or 50.26}$ 1
 2000
potential model
$30$ 2
 1981
K-matrix fit
$55$ 3, 4
 1973
DPWA 0$-$range fit (sol. B)
$20$
 1970
RVUE Constant K-matrix
$29$ $\pm6$
 1969
HBC Constant K-matrix
$50$ $\pm5$
 1967
HBC K-matrix fit
$34.1$ $\pm4.1$ 5
 1966
HBC
$37.0$ $\pm3.2$
 1965
HBC
$28.2$ $\pm4.1$ 5
 1965
HBC
 1 The KIMURA 2000 values are from fits A and B from a coupled-channel potential model using low-energy ${{\overline{\mathit K}}}{{\mathit N}}$ and ${{\mathit \Sigma}}{{\mathit \pi}}$ data, kaonic-hydrogen x-ray measurements, and our ${{\mathit \Lambda}{(1405)}}$ mass and width. The results bear mainly on the $\mathit nature$ of the ${{\mathit \Lambda}{(1405)}}$ : three-quark state or ${{\overline{\mathit K}}}{{\mathit N}}$ bound state.
 2 The MARTIN 1981 fit includes the ${{\mathit K}^{\pm}}{{\mathit p}}$ forward scattering amplitudes and the dispersion relations they must satisfy.
 3 An asymmetric shape, with $\Gamma$/2 = 41 MeV below resonance, 14 MeV above.
 5 Data of SAKITT 1965 are used in the fit by KITTEL 1966 .
References:
 KIMURA 2000
PR C62 015206 Nature of ${{\mathit \Lambda}{(1405)}}$
 MARTIN 1981
NP B179 33 Kaon $−$ Nucleon Parameters
 CHAO 1973
NP B56 46 ${{\overline{\mathit K}}}{{\mathit N}}$ Data and ${{\mathit \Lambda}{(1405)}}$
 MARTIN 1970
NP B16 479 $\mathit K$-Matrix Analysis of the Low Energy Data for ${{\mathit K}^{-}}{{\mathit p}}$ and ${{\mathit K}_{{2}}^{0}}{{\mathit p}}$ Reactions
 MARTIN 1969
PR 183 1352 Low-Energy ${{\overline{\mathit K}}}{{\mathit N}}$ and Pion-Hyperon Interactions. II. Applications of the ${{\mathit K}}$ Matrix Analysis
 Also
PR 183 1345 Low-Energy ${{\overline{\mathit K}}}{{\mathit N}}$ and Pion-Hyperon Interactions. I. ${{\mathit K}}$ Matrix Analysis of ${{\mathit K}^{-}}{{\mathit p}}$ Reactions
 KIM 1967
PRL 19 1074 Multichannel Phase Shift Analysis of ${{\overline{\mathit K}}}$ ${{\mathit n}}$ Interaction in the Region 0 to 550 ${\mathrm {MeV}}/\mathit c$
 KITTEL 1966
PL 21 349 The ${{\mathit K}^{-}}{{\mathit p}}$ Charge Exchange Interactions at Low Energies and Scattering Lengths Determination
 KIM 1965
PRL 14 29 Low Energy ${{\mathit K}^{-}}$ ${{\mathit p}}$ Interaction of the 1405 MeV ${{\mathit Y}^{*0}}$ Resonance as ${{\overline{\mathit K}}}{{\mathit N}}$ Bound State
 SAKITT 1965
PR 139 B719 Low Energy ${{\mathit K}^{-}}$ Meson Interactions in Hydrogen