Decays of theK−patom and the Λ(1405)

Role of five-quark components in radiative and strong decays of theΛ(1405)resonance

“…This latter generates 2 poles corresponding to the nominal Λ(1405), resulting in two different radiative decay widths. The low-energy pole leads to R=4.56, with Γ Λγ =16 keV, compatible with the value extracted within the above mentioned isobar model [57]. However, that model leads to a ratio compatible, within 1-σ, with both ≈1.2 and ≈0.5, so within the first two ranges.…”

Erratum: Radiative decays of theΣ0(1385)andΛ(1520)Taylor1, Mutchler2, Adams3 et al. 2005Phys. Rev. C11380View full textAdd to dashboardCite

“…Although the π 0 leakage into the γ channel is the dominant correction to the branching ratio, the final result still needs corrections for Σ + π − contamination and the contribution to the numerator from the reaction Λ(1405) → Λγ. Based on the measured 27±8 keV radiative width [19], we assume that the leakage of the Σγ channel into the γ region is small relative to the Λγ signal and that the leakage into the π 0 region is small compared to the Λπ 0 signal. The formula for the acceptance corrected branching ratio is…”

“…These are the only direct measurements in the literature. Burkhardt and Lowe [19] extracted model dependent branching ratios for Λ(1405) radiative decay from the kaon-proton capture data of Whitehouse et al [20]. The radiative decay of the Σ 0 (1385) has never been observed (Meisner[21] reports one event); only upper limits for the branching ratios have been established [22].…”

Electromagnetic decay of theΣ0(1385)toΛγ

“…Because this value is not measured directly, but is taken from the calculated value in Ref. [29], there is some uncertainty in it. Using the range of values for this branching ratio given in the literature, and recalculating its effect on our result, leads to the uncertainty quoted in line (8).…”

“…The values for BR(Λ(1405) → Λγ) = 5.4 ± 0.2 × 10 −4 % and BR(Λ(1405) → Σ 0 γ) = 2.0 ± 0.1 × 10 −4 % are taken from Ref. [29].…”