1. Precision Spectroscopy of Kaonic Helium-3 atoms X-rays at J-PARC RIKEN Nishina Center, Japan Masami IIO On behalf of the J-PARC E17 collaboration

2. SNU 1, SMI 2, LNF 3, RCNP 4, Kyoto Univ. 5, Univ. of Tokyo 6, RIKEN 7, KEK/J-PARC 8, Tokyo Tech 9, Tech. Munich Univ. 10 The J-PARC E17 Collaboration H. Bhang 1, M. Cargnelli 2, S. Choi 1, C. Curceanu 3, O. V. Doce 3, S. Enomoto 4, H. Fujioka 5, Y. Fujiwara 6, C. Guaraldo 3, T. Hashimoto 6, R. S. Hayano 6, T. Hiraiwa 5, M. Iio 7, S. Ishimoto 8, T. Ishiwatari 2, K. Itahashi 7, M. Iwasaki 7, 9, H.Kou 9, P. Kienle 10, J. Marton 2, Y. Matsuda 6, H. Noumi 4, H. Ohnishi 7, S. Okada 3, H. Outa 7, F. Sakuma 7, M. Sato 6, M. Sekimoto 8, H. Shi 6, D. Sirghi 3, F. Sirghi 3, T. Suzuki 6, K. Tanida 1, H. Tatsuno 6, M. Tokuda 9, D. Tomono 7, A. Toyoda 8, K. Tsukada 7, A. R. Vidal 3, E. Widmann 2, B. Wunschek 2, T. Yamazaki 6, 7, J. Zmeskal 2..

3. Introduction Experimental Method Preparation Status Summary Contents

4. Introduction

5. Strong-interaction Shift and Width of Kaonic Helium Last orbit of Kaonic atoms is sensitive to K - -nucleus strong-interaction. Nucleus absorption 2p (Strong-interaction) 2p 3d3d3d3d 2p (Coulomb-only) 2p  E 2p : Shift  2p : Width Atomic orbitals of Kaonic Helium 3d 2p X-rays 01/14

6. Long-standing Puzzle S. Hirenzaki, Y. Okumura, H. Toki, E. Oset and A. Ramos Phys. Rev. C 61 (2000) Last orbit energy level shift and width of kaonic atoms 02/14 Z=2 - Shift - - Width - - Shift - - Width - 1971 1979 1983 Avg. There has been a long debate! Past Measurements of K- 4 He Majority of Theoretical Suggestion: Very small shift (~0 eV) Experimental values: Very large shift (~40 eV)

7. Possibility of the Large Shift by Coupled-channel model Deeply-bound kaonic nuclei Deeply-bound kaonic nuclei predicted by Akaishi-Yamazaki U 0 : Real part of the K - -He strong interaction potential Y.Akaishi:EXA05 Calculation results of the 2p level shift by Prof. Akaishi ( Coupled-channel + Optical potential ) repulsive attractive K - - 4 He K - - 3 He Direct search for the kaonic nucleus (K - pp) J-PARC E15 Exp. (Dr. Tukada) 03/14

8. Strong interaction 2p level Shift of Kaonic Helium-4 (E570) 04/14 WG71: C. E. Wiegand, R. Pehl, PRL27, 1410 (1971) BT79: C. J. Batty, et al., NPA326, 455 (1979) BR83: S. Baird, et al., NPA392, 297 (1983)  E 2p = 2 2 (stat) 2 (sys) eV WG71: C. E. Wiegand, R. Pehl, PRL27, 1410 (1971) BT79: C. J. Batty, et al., NPA326, 455 (1979) BR83: S. Baird, et al., NPA392, 297 (1983) Physics Letters B 653 (2007) 387-391 KEK-E570 Publication BT90 BT90: Global fitting C. J. Batty, NPA508, 89c (1990) HZ00 HZ00: SU(3) Chiral unitary model S. Hirenzaki et al,. PRC61. 055205 (2000) FR06 FR06: Consideration for nonlinearly density dependence (~0.4 eV as the lowest) E. Friedman, private communication (2006) AK05 AK05: Coupled-Channel model Y. Akaishi, EXA05 proceedings (2005) BT90, HZ00, FR06 AK05 Theoretical suggestion

9. repulsive Difference between K - - 4 He and K - - 3 He 05/14 Y.Akaishi:EXA05 attractive K - - 4 He 2 2(stat) 2(sys) eV (KEK E570) repulsive Y.Akaishi:EXA05 attractive K - - 4 He 2 2(stat) 2(sys) eV (KEK E570) repulsive attractive Y. Akaishi and T. Yamazaki Phys. Rev. C 65 044005 (2002) K - - 3 He K - - 4 He By specific shrinkage effect, There is difference between K - - 4 He and K - - 3 He If it will be observed… Large difference Large difference No difference No difference It supports the Deeply-bound theory The potential is shallow No data exist yet on K - - 3 He x-rays ! J-PARC E17

10. Experimental Method

11. J-PARC E17 ( Precision Spectroscopy of K - - 3 He 3d  2p X-rays ) 06/14 For determination the 2p level shift with precision of a few eV ( E570 equivalent ) Beam-line Drift Chamber (BLC) Cherenkov counter Scintillation counter L 3 He CDC CDH CarbonDegrader SDDx8 K-K- x-rays KETEK products (http://www.ketek.net./) High-resolution High-resolution x-ray energy measurement Silicon Drift Detector (SDD) 180eV @6.4keV x2 SiLi (Past exp.) x2 Secondary charged particle Kaons stopping point measurement Kaons stopping point measurement with drift chambers for - Incident Kaons (BLC) - Secondary charged particles (CDC) Fiducial volume cut Fluorescence x-rays from Titanium and Nickel foils Channel to Energy Conversion In-beam energy calibration (-)(-) Ti&Ni foils

12. Preparation status

13. Experimental Setup 07/14 K1.8BR Experimental Area 5 m BeamlineSpectrometer Cylindrical Detector System (CDS) Liquid 3 He Target System Silicon Drift Detectors

14. Q7 Q8 D4 S3 D5 Hodoscope Scintillation counter stack Beam line chamber 1-2 Beam line chamber 3-4 Cherenkov counter Timing counters Beamline Spectrometer 08/14 First beam! (February, 2009) For E17 (Stop) 1) 0.7 GeV/c K(+/-) beam tuning 2) Momentum measurement by TOF 3) Range measurement For E15 (in-flight) 4) 1.0 GeV/c K(+/-) beam tuning 5) Momentum measurement by TOF Beam Tuning Plan Installation of the beamline detectors is completed. Start from 1.1 GeV/c unseparated (+)

15. Results of February tuning D5 D4 Q8Q8Q8Q8 Solenoid (CDS) Cherenkov counters (GC, AC, WC) BHD T0 Distance BHD-T0: 7.7m  -K TOF(cal.) : 2.3 nsec @1.1GeV/c  + :K + (cal.) : ~540:1 @1.1GeV/c - Slewing correction - Offset tune (offline) - Slewing correction - Offset tune (offline) BHD->T0 TOF (nsec) p e+/+/+e+/+/+ K+K+ Results  -K TOF: ~2.4 nsec  + :K + : ~9000:40 Success of the K + identification 0.7 GeV/c stopped K - (Autumn of 2009) 09/14

16. Cylindrical Detector System (CDS) 10/14 Hodoscope Counter (CDH) Cylindrical Drift Chamber (CDC)Solenoid Magnet 0.7 T Max magnetic field: 0.7 T Aperture:  =1.2m, L=1.2m Size: ID=300 mm, OD=1060 mm, L=950 mm 1816 ch Read-out : 1816 ch ~9 mm Drift length : ~9 mm (hexagonal) 15 Layer: 15 (7 super layers) A(3)U(2)V(2)A(2)U(2)V(2)A(2) Plastic Scintillator Size: 99x30x700 mm 3 (WxTxL) Configuration: 36 modules Strange and exotic systems, 17:30 Friday, Sep. 4 K. Tsukada “ ” “A search for deeply-bound kaonic nuclear states at J-PARC ”

17. Liquid 3 He Target for E15 11/14 Temperature in the Target Cell 1.3 K Pressure in the Target Cell 33 hPa Liq. 4 He Consumption 45 L/day Heat Load to the 1K Parts 0.19 W Cooling test with 200L 3 He gas Development of the 3 He cooling system was completed ! Measurement R&D for installation of the x-ray detection device to inside the target system Calculation

18. Silicon Drift x-ray Detector (SDD) New SDD & Preamp Effective area: 100 mm 2 KETEK products (http://www.ketek.net./) 12/14 In the vacuum chamber Testbench SDD Cover Preamp SDD Housing SDD Housing Temp. 140 K : 140 K Preamp Temp. 246 K chip : 246 K 160 K cover : 160 K ~150 eV Resolution: ~150 eV (FWHM) Fitted with Gauss+tail for K  / K  (common s & tail slope)

19. R&D forSDD installation to the LHe-3 target 13/14 Target cell (1.3 K) SDD (~120K) Radiation Shield (~80K) Pre-AMP (150~200K) Pre-AMP box (~80K) K-K-K-K- x-rays Parallel Session - Few-hadron systems 16:20 Friday, Sep. 4 Y. Fujiwara “” Y. Fujiwara “J-PARC E17 experiment”

20. Summary 14/14 Kaonic- 3 He Balmer-series x-rays will be measured with precision of a few eV (E17). We employed the similar technique as KEK-PS E570 (SDD, In-beam energy calibration, Fiducial volume cut ) (SDD, In-beam energy calibration, Fiducial volume cut ) Detector construction is in progress. (Beam line detectors, CDS, LHe-3 target, SDD) (Beam line detectors, CDS, LHe-3 target, SDD) K1.8BR beamline tuning was started. We succeeded in identification of K + by TOF measurement. Soon, we will start data taking at J-PARC

21. Thank you!

22. Spare Slides

23. Isospin-dependence of Kaonic Helium atoms K - - 4 He Shift K - - 4 He Width 2 2(stat) 2(sys) eV Not so large(~40 eV) U 0 MeV Y. Akaishi:EXA05 05/14 No data exist yet on K - - 3 He x-rays ! J-PARC E17 K - - 4 He Shift K - - 3 He Shift K - - 4 He Width 2 2(stat) 2(sys) eV U 0 MeV Y. Akaishi:EXA05 Large shift (~10eV) will be observed? Large shift (~10eV) will be observed?

24. 09/00 Beam Line Detectors for Stopped K - Experiment K-K-K-K- CDC End cap of Solenoid Cerenkov Counter (LC1, LC2) Scintillation counter (T1) Degrader for adjustment Main Carbon Degrader Scintillation counter (T0) Small Drift Camber (BLC) Liq. 3 He Target 88 mm 250 mm Small Beam Line Drift Chamber (BLC) Effective area: 80 x 80 mm 2 2.5 mm pitch 16 sense wires/layer 8 Layers (X X' Y Y' X X' Y Y') (X X' Y Y' X X' Y Y')

25. J-PARC K1.8BR Beam Line Main Ring (50 GeV) Switch Yard Hadron Hall J-PARC Hadron Facilities K1.8BR 06/14 T1 BG Pion Primary proton: 30GeV, 9  A (DAY-1) Horizontal (cm) Vertical (cm) 1.1 GeV/c 27.573 m 2.6 msr·% 6.0 mm 2.9 mm Max Momentum Beam line length Acceptance Horizontal extent @FF (rms) Vertical extent @FF (rms) Beam profile@FF Horizontal Vertical 06/14 ES1 0.1 M kaons/spill

26. Beam time estimation Monte Carlo simulation + Sanford-Wang To obtain statistics comparable to KEK-E570 E570 statistics : 3d->2p 1500events  2eV) for ~20 days (w/ 8 SDDs) K - yield : x 2 SDD acceptance : x 3 3.5 days Beam time for physics run: 3.5 days Primary Proton beam: 30GeV-9  A 08/14 At 1/10 of full intensity, E17 can be performed with ~1 month We don’t require the good K/Pi separation (for in-beam calibration) We proposed E17 as DAY-1 experiment at J-PARC. E17 has been approved in DAY-1, Stage-2.

27. Stopped-K - selection In-flight decay or Reactions SDDs&Foils Drift Chamber T0 counters K-K- Secondary charged particle L 4 He Ⅱ X-rays Degrader z-vertex Beam Direction Light output The background events in the target cell were removed by the T0 counters. Target region

28. Energy calibration SDD self- triggered events High statistical High statistical characteristic characteristic X-ray peaks of X-ray peaks of Ti & Ni Ti & Ni Stopped-K - triggered events Fiducial volume cut Fiducial volume cut Stopped-K - selection SDD timing cut SDD timing cut Channel to Energy Conversion

29. Spectrum analysis Main peak Voigt function Convolution of the Gaussian and Lorentzian Response of SDD Shelf + Tail function Shelf function : Convolution of the Gaussian and Step function Tail function : Convolution of the Gaussian and Exponential High statistical spectral fitting (Self-triggered events) The parameters were estimated Compton scattering Tail function K-K-K-K- Scattering Monte Carlo Simulation (Geant4) K - - 4 He X-rays(3d  2p) Compton scattering effect The parameters were estimated by fitting the simulated spectrum Pileup effect Gaussian Typical pileup waveforms (FADC) The parameters were estimated by FADC data

30. Systematic error Response function Fitting by the high-statistic spectra for self-triggered events Consideration of the energy dependence of the detector resolution Intensity ratios of the shelf and tail components to main-peak :  : average energy for electron-hole creation (3.81 eV) W N : Contribution noise to resolution F: Fano factor (~0.12 for Si), E: X-ray energy ~ 1 eV Compton scattering LECS(Low Energy Compton Scattering) package The error of the total compton scattering cross section was few percent 5 % (Intensity fluctuation) = ~ 0.4 eV Pileup effect The error of intensity ratio was plus or minus 10 percent from the error of pileup evens identification by the FADC analysis 10 % (Intensity fluctuation) = ~ 0.4 eV

31. Derivation of the 2p level strong interaction shift TransitionE570 measurementsEM calculation 3d 2p 6467.0 2.5 6467.0 2.5 (stat)6463.5 4d 2p 8723.5 4.5 8723.5 4.5 (stat)8721.7 5d 2p 9761.4 7.6 9761.4 7.6 (stat)9766.8 (T. Koike) EM calculation (T. Koike) - Vacuum polarization - Nuclear finite size effect - Relativistic recoil effect - Electron screening effect - Totally corrected energy levels The strong interaction shift of 3d, 4d and 5d levels were negligibly small 6467 3 (stat) 2 (sys) eV 3d 2p transition energy : 6467 3 (stat) 2 (sys) eV 2 2 (stat) 2 (sys) eV 2p level strong interaction shift : 2 2 (stat) 2 (sys) eV

32. Spare Slides (E15)

33. Deeply-bound Kaonic Nuclei 01/12 Y.Akaishi & T.Yamazaki, PLB535, 70(2002). methodB. E.Width Akaishi, Yamazaki PLB535(2002) 70 ATMS48 MeV61 MeV K. Swe Mynt, Akaihi APFB05 Gaussian base Rearrangement-channel Ivanov, Kienle, Marton, Widmann nucl-th/0512037 Field theoretic approach 115 MeV28 MeV Dote, Weise YKIS06 AMD Ikeda, Sato HYP06 Faddeev55 MeV40 MeV Arai, Yasui, Oka JPS06-2  *N model 87 MeV Shevechenko, Gal, Mares nucl-yh/0610022 Faddeev55-70 MeV95-110 MeV Koike, Harada PLB652, 262 (2007).DWIA Recent theoretical progress (K - -pp)

34. Experimental Search for Kaonic Nuclei 02/12 Deeply-bound Kaonic Nuclei really exist? Deeply-bound Kaonic Nuclei really exist? FOPI/GSI ＦＩＮＵＤＡ K - pp? AGS E930 E548/KEK E549/KEK OBELIX O(K-,n) There is no evidence that it exists or not ! We will perform the new experiment at J- PARC (E15)

35. J-PARC E15 ( Search for K - -pp deeply-bound kaonic nuclear state ) 04/11 + K-K-K-K- 3 He NC 15 m15 m + K - pp n Reaction Missing mass spectroscopy K - pp search with TOF measurement of neutron  pp ---- Decay Invariant mass reconstruction K - pp search with decay particles measurement

36. Expected Spectrometer Performance I Missing mass resolution Missing mass resolution –Neutron flight path = 12 m –ToF time resolution = 150 ps

37. Expected Spectrometer Performance II mass resolution K-pp   p   p  w/o chamber-resolution5.8 MeV/c 2 1.6MeV/c 2 w/ chamber-resolution18.7MeV/c 2 2.5MeV/c 2 momentum resolution for , K, p Calculated using Geant4 Invariant mass of  p (MeV)  0 channel  channel  K-pp = 60 MeV we can distinguish the two non- mesonic decay modes for K - -pp – K-pp   p  p  -p – K-pp   0 p   p   p  -p Invariant mass resolution for K - -pp and 

38. Signals from K-pp and “Two nucleon absorption” K-K-K-K- 3 He reaction 3 He(K-,n) K - pp formation @ 1GeV/c K- and B.E. = 100 MeV ~ 1.3 GeV/c @ 1GeV/c K- ~ 1.5GeV/c neutron Two nucleon absorption Two nucleon absorption K-K-K-K- 3 He reaction  p p neutron   p p (spectator) Almost stop ~ 500 MeV/c “Two nucleon absorption process” can be identified!

39. Expected Kinematics for K - -pp Decay  vtx K - -pp vtx p p -- n ~1300MeV/c ~400MeV/c ~150MeV/c ~500MeV/c p p -- Binding energy = 100MeV/c 2 Isotropic decay of K - -pp with forward neutron Calculated using Geant4

40. Neutron Counter 09/11 20x5x150 cm 3 Plastic Scintillator Configuration : 16 (wide) x 7 (depth) Surface area : 3.2m X 1.5m Surface area : 3.2m X 1.5m 3.2 m 1.5 m E549 neutron counter set x2 E15 NC Support Frame