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Precision Spectroscopy of Kaonic Helium-3 atoms X-rays at J-PARC

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. The J-PARC E17 Collaboration. H. Bhang 1 , M. Cargnelli 2 , S. Choi 1 , C. Curceanu 3 ,

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Precision Spectroscopy of Kaonic Helium-3 atoms X-rays at J-PARC

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  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. The J-PARC E17 Collaboration H. Bhang1, M. Cargnelli2, S. Choi1, C. Curceanu3, O. V. Doce3, S. Enomoto4, H. Fujioka5, Y. Fujiwara6, C. Guaraldo3, T. Hashimoto6, R. S. Hayano6, T. Hiraiwa5, M. Iio7, S. Ishimoto8, T. Ishiwatari2, K. Itahashi7, M. Iwasaki7, 9, H.Kou9, P. Kienle10, J. Marton2, Y. Matsuda6, H. Noumi4, H. Ohnishi7, S. Okada3, H. Outa7, F. Sakuma7, M. Sato6, M. Sekimoto8, H. Shi6, D. Sirghi3, F. Sirghi3, T. Suzuki6, K. Tanida1, H. Tatsuno6, M. Tokuda9, D. Tomono7, A. Toyoda8, K. Tsukada7, A. R. Vidal3, E. Widmann2, B. Wunschek2, T. Yamazaki6, 7, J. Zmeskal2 .. SNU1, SMI2, LNF3, RCNP4, Kyoto Univ.5, Univ. of Tokyo6, RIKEN7, KEK/J-PARC8, Tokyo Tech9, Tech. Munich Univ.10

  3. Contents Introduction Experimental Method Preparation Status Summary

  4. Introduction

  5. Strong-interaction Shift and Widthof Kaonic Helium Last orbit of Kaonic atoms is sensitive to K--nucleus strong-interaction. Atomic orbitals of Kaonic Helium 3d 3d 2p X-rays DE2p: Shift G2p: Width (Strong-interaction) 2p absorption (Coulomb-only) 2p Nucleus 01/14

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

  7. Possibility of the Large Shift by Coupled-channel model Deeply-bound kaonic nucleipredicted by Akaishi-Yamazaki Direct search for the kaonic nucleus (K-pp) J-PARC E15Exp. (Dr. Tukada) Calculation results of the 2p level shift by Prof. Akaishi ( Coupled-channel + Optical potential ) U0: Real part of the K--He strong interaction potential Y.Akaishi:EXA05 K--3He attractive K--4He repulsive 03/14

  8. Strong interaction 2plevel Shift of Kaonic Helium-4 (E570) Theoretical suggestion DE2p = 2 2 (stat) 2 (sys) eV BT90, HZ00, FR06 AK05 BT90: Global fitting C. J. Batty, NPA508, 89c (1990) HZ00: SU(3) Chiral unitary model S. Hirenzaki et al,. PRC61. 055205 (2000) FR06: Consideration for nonlinearly density dependence (~0.4 eV as the lowest) E. Friedman, private communication (2006) AK05: Coupled-Channel model Y. Akaishi, EXA05 proceedings (2005) 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) 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) KEK-E570 Publication Physics Letters B 653 (2007) 387-391 04/14

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

  10. Experimental Method

  11. J-PARC E17 (Precision Spectroscopy of K--3He 3d 2p X-rays) ( E570 equivalent ) Silicon Drift Detector (SDD) Fiducial volume cut High-resolutionx-ray energy measurement For determination the 2p level shift with precision of a few eV Kaonsstopping point measurement with drift chambers for - IncidentKaons (BLC) - Secondary charged particles (CDC) 180eV @6.4keV SiLi(Past exp.) x2 KETEK products (http://www.ketek.net./) Secondary charged particle CDH In-beam energy calibration CDC Beam-line Drift Chamber (BLC) Fluorescence x-rays from Titaniumand Nickelfoils K- Carbon Degrader x-rays SDDx8 L3He Channel to Energy Conversion (p-) Cherenkov counter Scintillation counter Ti&Nifoils 06/14

  12. Preparation status

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

  14. Beamline Spectrometer D5 Installation of the beamline detectors is completed. First beam! (February, 2009) Q8 Cherenkov counter D4 Beam Tuning Plan Timing counters 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 line chamber 3-4 Beam line chamber 1-2 Q7 Scintillation counter stack S3 Start from 1.1 GeV/c unseparated (+) Hodoscope 08/14

  15. Results of February tuning Distance BHD-T0: 7.7m p-K TOF(cal.) : 2.3 nsec @1.1GeV/c p+:K+ (cal.) : ~540:1 @1.1GeV/c T0 D4 Cherenkov counters (GC, AC, WC) Q8 BHD D5 Solenoid (CDS) - Slewing correction - Offset tune(offline) e+/m+/p+ p Results p-K TOF: ~2.4 nsec p+:K+: ~9000:40 Success of the K+ identification K+ 0.7 GeV/c stopped K- (Autumn of 2009) BHD->T0 TOF (nsec) 09/14

  16. Cylindrical Detector System (CDS) Solenoid Magnet Cylindrical Drift Chamber (CDC) Size: ID=300 mm, OD=1060 mm, L=950 mm Read-out : 1816 ch Drift length: ~9 mm (hexagonal) Layer: 15 (7 super layers) A(3)U(2)V(2)A(2)U(2)V(2)A(2) Hodoscope Counter (CDH) Plastic Scintillator Size: 99x30x700 mm3 (WxTxL) Configuration: 36 modules Max magnetic field: 0.7 T Aperture: f=1.2m, L=1.2m Strange and exotic systems, 17:30 Friday, Sep. 4 K. Tsukada “A search for deeply-bound kaonic nuclear states at J-PARC ” 10/14

  17. Liquid 3He Target for E15 Cooling test with 200L 3He gas Calculation Measurement Development of the 3He cooling system was completed ! R&D for installation of the x-ray detection device to inside the target system 11/14

  18. Silicon Drift x-ray Detector (SDD) In the vacuum chamber Testbench New SDD & Preamp SDD SDD Housing Effective area: 100 mm2 KETEK products (http://www.ketek.net./) SDD Housing Temp. : 140 K Preamp Temp. chip : 246 K cover : 160 K Cover Fitted with Gauss+tailfor Ka / Kb (common s & tail slope) Preamp KETEK products Resolution: ~150 eV(FWHM) 12/14

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

  20. Summary Kaonic-3He 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 ) Detector construction is in progress. (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 14/14

  21. Thank you!

  22. Spare Slides

  23. Isospin-dependence of Kaonic Helium atoms Y. Akaishi:EXA05 Y. Akaishi:EXA05 K--4He Width K--4He Width Not so large(~40 eV) K--4He Shift K--3He Shift K--4He Shift K--4He Shift 2 2(stat) 2(sys) eV Large shift (~10eV) will be observed? 2 2(stat) 2(sys) eV U0 MeV U0 MeV No data exist yet on K--3He x-rays ! J-PARC E17 05/14

  24. Beam Line Detectors for Stopped K- Experiment Small Drift Camber (BLC) End cap of Solenoid Scintillation counter (T1) Main Carbon Degrader K- Degrader for adjustment Liq. 3He Target Scintillation counter (T0) Cerenkov Counter (LC1, LC2) CDC Small Beam Line Drift Chamber (BLC) Effective area: 80 x 80 mm2 2.5 mm pitch 16 sense wires/layer 8 Layers (X X' Y Y' X X' Y Y') 88 mm 250 mm 09/00

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

  26. Beam time estimation To obtain statistics comparable to KEK-E570 Primary Proton beam: 30GeV-9mA E570 statistics : 3d->2p 1500events (s ~2eV) for ~20 days (w/ 8 SDDs) K- yield : x 2 SDD acceptance : x 3 Beam time for physics run: 3.5 days Monte Carlo simulation + Sanford-Wang 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. 08/14

  27. Stopped-K- selection The background events in the target cell were removed by the T0 counters. Secondary charged particle Drift Chamber Degrader SDDs&Foils Light output K- X-rays L4HeⅡ T0 counters Target region z-vertex In-flight decay or Reactions Beam Direction

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

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

  30. Systematic error Response function Intensity ratios of the shelf and tail components to main-peak : Fitting by the high-statistic spectra for self-triggered events Consideration of the energy dependence of the detector resolution w: average energy for electron-hole creation (3.81 eV) WN: 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 The strong interaction shift of 3d, 4d and 5d levels were negligibly small EM calculation (T. Koike) - Vacuum polarization - Nuclear finite size effect - Relativistic recoil effect - Electron screening effect - Totally corrected energy levels 3d 2p transition energy : 6467 3 (stat) 2 (sys) eV 2p level strong interaction shift : 2 2 (stat) 2 (sys) eV

  32. Spare Slides (E15)

  33. Deeply-bound Kaonic Nuclei Y.Akaishi & T.Yamazaki, PLB535, 70(2002). Koike, Harada PLB652, 262 (2007).DWIA Recent theoretical progress (K--pp) 01/12

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

  35. J-PARC E15 (Search for K--pp deeply-bound kaonic nuclear state) K- 3He K-pp n Reaction + + L Decay p- p p NC 15m Missing mass spectroscopy K-ppsearch with TOF measurement of neutron Invariant mass reconstruction K-ppsearch withdecay particles measurement The conclusive evidence will be obtained with measurement of formation and decay by J-PARC E15 04/11

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

  37. Expected Spectrometer Performance II Calculated using Geant4 momentum resolution for p, K, p • we can distinguish the two non-mesonic decay modes for K--pp • K-pp Lp pp-p • K-pp S0p gLpgpp-p S0 channel L channel GK-pp= 60 MeV Invariant mass resolution for K--pp and L Invariant mass of Lp (MeV)

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

  39. Expected Kinematics for K--pp Decay Calculated using Geant4 Binding energy = 100MeV/c2 Isotropic decay of K--pp with forward neutron p p- p p- ~400MeV/c ~150MeV/c n Lvtx K--pp vtx ~1300MeV/c p p ~500MeV/c

  40. Neutron Counter E549 neutron counter set x2 3.2 m E15 NC Support Frame 1.5 m 20x5x150 cm3Plastic ScintillatorConfiguration : 16 (wide) x 7 (depth) Surface area : 3.2m X 1.5m 09/11

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