1. Probing strong interaction with kaonic atoms - from DA  NE to J-PARC Johann Zmeskal Stefan Meyer Institute for Subatomic Physics Vienna, Austria The 12 th International Conference on Hypernuclear and Strange Particle Physics September 7-12, 2015 Tohoku University, Sendai, Japan Stefan Meyer Institute

2. Outline HYP2015 Motivation Measuring principle SIDDHARTA setup at DA  NE Results of kaonic helium and hydrogen Kaonic deuterium at J-PARC Summary

3. Low-energy KN interacction  Chiral perturbation theory was developed for  p,  is not applicable for KN systems non-perturbative coupled channels approach based on chiral SU(3) dynamics HYP2015

4. Exotic (kaonic) atoms – probing strong interaction  testing chiral symmetry breaking in systems with strangeness Why kaonic hydrogen?  observable: hadronic shift ε 1s and width Γ 1s  can be connected to KN scattering lengths  scattering lengths, no extrapolation to zero energy Motivation: Low-energy KN systems

5. 1) U.-G. Meißner, U.Raha, A.Rusetsky, Eur. phys. J. C35 (2004) 349 next-to-leading order, including isospin breaking Scattering lengths Deser-type relation 1) connect the observables shift  1s and width  1s of the 1s state with the real and imaginary part of the scattering length ɑ K-p (µ C reduced mass of the K  p system,  fine-structure constant)

6. n=1 p e-e- K-K- “normal” hydrogen“exotic” (kaonic) hydrogen n=1 n=2 n~25 K-K- X-ray 2p → 1s K  transition Forming “exotic” atoms HYP2015

7. Stark-mixing l =0 1 2 n-1 n ~ 25 3 2 1 observable hadronic shift and broadening  1s  1s external Auger effect chem. de-excitation Coulomb de-excitation X-ray radiation K K nuclear absorption Cascade processes

8. X-ray transitions to the 1s state HYP2015

9. Kaonic hydrogen atoms at DA  NE e + -e - collider LINAC Accu. HYP2015

10.  K+K+ K-K- ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee DA  NE principle operates at the centre-of-mass energy of the  meson mass m = 1019.413 ±.008 MeV width  = 4.43 ±.06 MeV  produced via e + e - collision with  (e + e - →  ) ~ 5 µb   production rate 2.5 x 10 3 s -1 → monochromatic kaon beam (127 MeV/c) HYP2015

11. KpXDEARSIDDHARTA @ KEK @ DA  NE DetectorSi(Li)CCDSDD Energy resolution350 eV180 eV150 eV Time resolutionµs30 sµs Thicknessmm30 µm400 µm Efficiency at 6 keV~ 100%~ 60%~ 100% Active area120 cm 2 116 cm 2 114 cm 2 Detectors for K - p experiments HYP2015

12. SDD window frame (pure Al 99.999%) flexible Kapton boards pre-amplifier board HV+LV distribution board Development of large area SDDs FP-6 EU programme: HadronPhysics HYP2015 3x100 mm 2

13. FWHM = 150 eV @ 6keV Excellent energy resolution HYP2015

14. Alu-grid Side wall: Kapton 50 µm Kaon entrance Window: Kapton 75 µm working T 25 K working P 1.5 bar Lightweight cryogenic target cell HYP2015

15. Advanced Seminar Series Particles and Interactions SIDDHARTA target - detector HYP2015

16. SDDs degrader Scintillators Production data K + K - pairs produced at DA  NE Data taking scheme at DA  NE HYP2015 triple coincidence

17. “X-ray tube” data taken with “beam” ON Data taking scheme at DA  NE HYP2015

18. “X-ray tube” data taken estimated systematic error ~ 3-4 eV SDD X-ray energy spectra energy [keV] counts / 30eV HYP2015

19. SDD X-ray energy spectra HYP2015

20. K - 3 He (3d-2p) Ti K  K-CK-C K-OK-O K-NK-N QED value: E em = 6224.6 eV PLB 697(2011)199 First observation of K- 3 He X-rays Kaonic helium-3 measurement HYP2015

22. Kaonic helium results HYP2015  E17 at J-PARC (Shinji Okada)

23. width  1s  [eV] KpX -5005000 0 200 400 600 800 1000 shift  1s [eV] Davies et al, 1979 Izycki et al, 1980 Bird et al, 1983 repulsive attractive KpX (KEK) M. Iwasaki et al, 1997  = - 323 ± 63 ± 11 eV  = 407 ± 208 ± 100 eV DEAR results Kaonic hydrogen: KpX and DEAR results HYP2015

24. Kaonic hydrogen @ SIDDHARTA HYP2015 Calibration data with X-ray tube All events (“self trigger”) Coincidence: K + K  and SDD timing

25. K - p spectrum after BG subtraction HYP2015

26. State of the art: Kaonic hydrogen ε 1s = -283 ± 36(stat) ± 6(syst) eV Γ 1s = 541 ± 89(stat) ± 22(syst) eV HYP2015 SIDDHARTA

27. HYP2015 Improved constraints on chiral SU(3) dynamics from kaonic hydrogen, Y. Ikeda, T. Hyodo and W. Weise, PLB 706 (2011) 63

28. W. Weise HYP2015

29. 20 Institutes / 10 Countries K-d at J-PARC

30. HYP2015 K  d at J-PARC X-ray detection: large active area charge particle tracking lightweight cryogenic target stopped K 

31. 8 x 8 mm 2 single SDD Array: 9 SDDs (8 x 8 mm 2 each) 12 x 12 mm single SDD FBK production: 4’’ wafer 6’’ wafer upgrade just finished New Silicon Drift Detector developed by Politech Milano and FBK-Trento, Italy 26mm

32. 16 mm + 2 mm 8 mm border 1 mm SDD active area 8 mm x 4 + 4 mm + 2 mm = 38mm 8765 4321 additional border 2 mm Design of the new SDD array ceramic boards cell size: 8 x 8 mm 2 cells per array: 8 active area: 5.12 cm 2 total area: 6.84 cm 2 HYP2015

33. Prototype of the new 4x2 SDD array SDD-chip back side with bonding pads connector 9 holes for bondings CUBE preamplifier SDD-chip glued to ceramic board, bonded to CUBE preamplifier

34. New SDD technology with CUBE preamplifier HYP2015 55 Fe spectrum 123.0 eV FWHM SDD characteristics: area = 64 mm 2 T = - 100°C first series of new SDD-chips available

35. HYP2015 Synchronous and asynchronous background Synchronous BG

36. charged particle veto charged particle tracking HYP2015

37. K1.8BR experimental area J-PARC K1.8BR spectrometer neutron counter beam dump beam sweeping magnet liquid 3 He-target system CDS beam line spectrometer K-K- γ, n p 15m

38. HYP2015 T1 T0 main degrader CDC BLC CDH Solenoid SDD and deuterium target CDH...cylindrical detector hodoscope CDC...cylindrical drift chamber T0.......beam line counter T1.......beam line counter BLC....beam line chamber K  d within the K1.8BR spectrometer

39. HYP2015 KK start counter T0 entrance window 75 µm Kapton Al reinforced side wall 75 µm Kapton 12 x 4 SDD arrays SDD cooling and support target cell: l = 160 mm, d = 65 mm target pressure max.: 0.35 MPa target temperature: 23 – 30 K SDD active area: 246 cm 2 density: 5% LHD (29K/0.35 MPa) Combined target and SDD design

40. HYP2015 K  d scattering lengths - theory a Kd [fm]  1s [eV]  1s [eV]Reference -1.55 + i 1.66- 969938Weise 2015 [2] -1.58 + i 1.37- 887757Mizutani 2013 [4] -1.48 + i 1.22- 7871011Shevchenko 2012 [5] -1.46 + i 1.08- 779650Meißner 2011 [1] -1.42 + i 1.09- 769674Gal 2007 [6] -1.66 + i 1.28- 884665Meißner 2006 [7] -1.62 + i 1.91- 10801024Oset 2001 [3] [1] M. Döring, U.-G. Meißner, Phys. Lett. B 704 (2011) 663 [2] W. Weise, arXiv:1412.7838[nucl-theo]2015 [3] S.S. Kamakov, E. Oset, A. Ramos, Nucl. Phys. A 690 (2001) 494 [4] T. Mizutani, C. Fayard, B. Saghai, K. Tsushima, Phys. Rev. C 87, 035201 (2013), arXiv:1211.5824[hep-ph] [5] N.V. Shevchenko, Nucl. Phys. A 890-891 (2012) 50-61 [6] A. Gal, Int. J. Mod. Phys. A22 (2007) 226 [7] U.-G. Meißner, U. Raha, A. Rusetsky, Eur. phys. J. C47 (2006) 473 for simulation: shift = - 800 eV width = 800 eV

41. HYP2015 Geant4 simulated K  d X-ray spectrum for 160 kW·weeks achievable precision: shift: 60 eV width:140 eV signal: shift - 800 eV width 750 eV density: 5% (LHD) detector area: 246 cm 2 K  yield: 0.1 % yield ratio as in K  p S/B ~ 1 : 3 QED  vertex cut  charged particle veto  asynchronous BG KK KK K high

42. SIDDHARTA@ DA  NE X-ray spectra measured with several targets:  K  p: provided the most precise values (PLB 704 (2011) 113)  K  d: first exploratory measurement (Nuclear Physics A 907 (2013) 69)  K  3 He: first-time measurement (PLB 697 (2011) 199)  K  4 He: measured in gaseous target (PLB 681 (2009) 310) K  d at J-PARC (P57)  stage 1 approval – new SDDs with cryogenic gas target – K1.8 BR spectrometer Summary HYP2015