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[K - pp] search now is a “ Λ p puzzle”. Several experiments measure different ( Λ p) invariant mass signals: are they indeed in such a disagreement ?. E549 vs FINUDA. H. Outa, E549 Collaboration, talk given at this workshop. S. Piano, FINUDA Collaboration, talk given at this workshop.
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[K-pp] search now is a “Λp puzzle” Several experiments measure different (Λp) invariant mass signals: are they indeed in such a disagreement ? E549 vs FINUDA H. Outa, E549 Collaboration, talk given at this workshop S. Piano, FINUDA Collaboration, talk given at this workshop K-4He → Σπ(3N) (ΣN→ΛN) K-4He → ΣN(3N) ? Unlikely due only to ΣN conversion K-4He → ΛN(2N) not acceptance corrected not acceptance corrected
FINUDA: ΣN→ΛN conversion reactions Simulations: Λp Invariant Mass ΣN→ΛN cannot explain the FINUDA Λp bump: Inv Mass Spectra is out of range and/or Angular Distribution has a different shape K-6Li→Σ0,+π0,-4Hgs Σ0p→Λp Σ+n→Λp K-6Li→Σ0p4Hgs Σ0→Λγ K-6Li→Λp4Hgs K-6Li→Σ0,+n4Hgs Σ0p→Λp Σ+n→Λp Simulations: Λp angular distribution K-6Li→Σ0,-p4Hgs Σ0n→Λn Σ-p→Λn
G. Bendiscioli et al., NPA789(2007)222 G. Bendiscioli et al., EPJA40(2009)11 p4He→(pπ-)pK0sX ¯ Λp inv mass: FINUDA vs OBELIX ppπ- invariant mass spectrum T. Buran et al., PL20(1966)318 K-(CF3Br)→ΛpX K-6Li→Σ0p4Hgs Σ0→Λγ S. Piano, FINUDA Collaboration, talk given at this workshop K-6Li→Λp4Hgs K-6Li→Λπ0,+,-p4Hgs not acceptance corrected not acceptance corrected All these reactions are can occur on d only
Λp inv mass: FOPI vs (old) K-d experiments N. Hermann, FOPI Collaboration, talk given at this workshop The signal is compatible with a K-d absorption with pion production K-d→(Σ+n)π-→(Λp)π- D. Eastwood et al., PRD3(1971)2603 K-d→Λp π-X (1.45 GeV/c and 1.65 GeV/c) Signal also compatible with a threshold (ΣN) cusp effect (no resonance needed) D. Cline et al., PRL20(1968)1452 K-d→Λp π-X (400 MeV/c)