1. Wycech, Meson- 2010 Testing Λ(1405) with K-mesic atoms S.Wycech IPJ, Warsaw The purpose Λ(1405) is the dorway and the mechanism to bind the „K-mesic nuclei”

2. Wycech, Meson- 2010 Two approaches to Λ(1405) Phenomenology K – matrix fitted to data + dispersion relations Extrapolation below KN, E ~ 1405 MeV PDG, R.Dalitz, A.Martin.. many others since 1970 ▪ Chiral models SU(3) symmetric driving force, pole in Σ π, pole in KN plane, E ~ 1420 MeV W.Weise, E.Oset.. others since 2000

3. Wycech, Meson- 2010 Experimental check K N  Σ π below threshold in final states not conclusive provides amplitude a(K N, Σ π) no a(K N,KN)

4. Wycech, Meson- 2010

5. Two new (?) suggestions to extract KN amplitudes from 1)Upper atomic levels 2) Atomic  nuclear radiative transitions

6. Wycech, Meson- 2010 „upper levels „ s p d …. n= 3 n= 2 „ upper ” n= 1 „ lower „

7. Wycech, Meson- 2010 Upper levels „do not fit „ E. Friedman, A.Gal Im a= 0.37 fm upper levels Im a= 0.94 fm lower levels Г ~ Im a (KN, E = - EBINDING - ERECOIL ) 5 - 25 % accurate in upper levels impulse approx. not valid in lower levels

8. Wycech, Meson- 2010 Nucleon levels „seen” in atoms V(r) radial distance lower upper levels

9. Wycech, Meson- 2010 Parallel case, antiprotonic atoms Nuclear regions studied in atomic levels lower upper cold capture ↓ ↓ ↓ ρ(r)

10. Wycech, Meson- 2010 P-bar N subthreshold energies involved in p-bar atoms -40 -20 0 MeV P D T He 4

11. Wycech, Meson- 2010 Im a(E) extracted from light antiprotonic atoms - PS 207 data Paris model

12. Wycech, Meson- 2010 Im a KN (E) extracted from upper widths

13. Wycech, Meson- 2010 Im a(KN) extracted from upper widths

14. Wycech, Meson- 2010 Favorite situation for studying Г(upper): one or few nucleon orbitals perfect P,D,He, very good Li, Be, C, N,O, resonable in almost all atoms

15. Wycech, Meson- 2010 K-neutron dominated widths Upper widths due mostly to Kn, S + P wave Pb  Im a (K – n) Apparently dominated by Σ (1385)

16. Wycech, Meson- 2010 Another possibility to study sub-threshold elastic KN or K-nucleus amplitude

17. Wycech, Meson- 2010 K-hydrogen  Λ(1405 ) + γ Kaons lost in cascade Kaonic Hydrogen ~ 95% lost How many go to Λ(1405 ) + γ ?

18. Wycech, Meson- 2010 Old BNL experiment K – p  Σ(1190) γ Found on the level of 1/1000 D.A.Whitehouse..PRL.63(89)1352; K.D.Larsen.. Phys.Rev D47(93)799 K – p  Λ(1405) γ Is it feasible ? What is the line shape ?

19. Wycech, Meson- 2010 High energy photons from K - p atom

20. Wycech, Meson- 2010 Gamma rays to Λ(1405) 5 10 -3 of captures from ( n P) levels s p d n= 3 n= 2 n= 1 Λ(1405)

21. Wycech, Meson- 2010 Occupation and capture from all (n,P) states estimated captures from n P states in gas targets ~ few % of stopped K mesons Total chance for γ transition ~ 0.001-0.0001 per stopped kaon

22. Wycech, Meson- 2010 Kaonic deuterium atom  KNN Deep state ~100 MeV ( FINUDA, DISTO) Very small chance Weakly bound or virtual state ~ 47 MeV P+ Σ(1385) sw Phys. Rev C 79 Good chance

23. Wycech, Meson- 2010 Line shape Г = ∫ dk S(k) S(k) = Im T KN,KN (E o –k) k G KN (k)

24. Wycech, Meson- 2010 LINE SHAPE resonance●propagator●phase space Σ π T G KN γ p K -

25. Wycech, Meson- 2010 Summary Upper widths in K atoms may determine Im T KN,KN (M K + M N – E ) for E = 0 - 40 MeV K -Atom  K-Nuclear + γ may give elastic Im T KNUCLEUS (M K + M N – E ) Experiments are difficult

26. Wycech, Meson- 2010

28. Upper levels –suggestions Interesting measurements He (2p ) Be, C, repetition Sn 112,116,118,124 – different proton bindings Pb 208 Kn parameters in addition to D