Experimental confirmation of the Lambda(1405) Ansatz from resonant formation of a K-p quasi-bound state in K- absorption by 3He and 4He

Abstract

The Sigma-pi invariant-mass spectra in the resonant capture of K- at rest in 4He, 3He and d are calculated by a coupled-channel procedure for a K-p quasi-bound state of an arbitrary chosen mass (M) and width (Gamma). A chi2 analysis of old 4He bubble chamber data shows a dominance of the s-orbit absorption, and yielded M = 1405.5 ^(+1.4)_(-1) MeV/c2 and Gamma = 26 ^(+4)_(-3) MeV, where a possible population of Sigma0(1385) and also a small p-orbit capture contribution are taken into account. This result confirms the Lambda(1405) ansatz, whereas recent chiral-SU(3) predictions (M ~ 1420 MeV/c2) are excluded. A more stringent test by using a 3He target is proposed .

6 pages, 6 figures

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Cited by in corpus (17)

• The nature of the Lambda(1405) resonance in chiral dynamics
• Lattice QCD Evidence that the Lambda(1405) Resonance is an Antikaon-Nucleon Molecule
• Baryonic resonances close to the Kbar-N threshold: the case of Lambda(1405) in pp collisions
• Hadron Physics at J-PARC
• Faddeev-Chiral Unitary Approach to the $K^{-}d$ scattering length
• Understanding the Nature of $\Lambda (1405)$ through Regge Physics
• Single-pole nature of Lambda (1405) and structure of K-pp
• Resonant formation of Lambda(1405) by stopped-K- absorption in deuteron
• Pole position of $\Lambda (1405)$ measured in $d(K^{-},n)\pi \Sigma$ reactions
• The K1.8BR spectrometer system at J-PARC
• Three- and four-body kaonic nuclear states: Binding energies and widths
• Theoretical analysis of Lambda(1405) --> (Sigma pi)^0 mass spectra produced in p+p --> p + Lambda(1405) + K^+ reactions
• Structure of $\Lambda$(1405) resonance and $\gamma p\to K^{+}+(\pi \Sigma {)}^0$ reaction
• Trace of $\Lambda (1405)$ resonance in low energy $K^{-}+{}^3\mathrm{He}\to ({\pi }^0{\Sigma }^0)+d$ reaction
• Deduction of $M(Sigmapi)$ for $Lambda(1405)$ with mixed $T_{Sigmapileftarrow{K}^{-}p}and{T}_{SigmapileftarrowSigmapi}$ from Hemingway's data
• Investigation of the $\bar{K}$--${}^6$Li Interaction and the Search for the $\Lambda (1405)$ Resonance
• Study of ${\Sigma }^{+}{\pi }^{-}$ Invariant Mass spectrum with the KLOE detector; preliminary results and possible hints for ${\Sigma }^{+}n$ internal conversion