1. Oct. 13 th 2006 -ray spectroscopy study of and Yue Ma Department of Physics Tohoku University

2. Oct. 13 th 2006Hyp06 Collaboration List for KEK-PS E566 Tohoku Univ.: T. Koike, S. Kinoshita, Y. Ma, Y. Miura, Y. Miyagi, K. Shirotori, T. Suzuki, H. Tamura, K. Tsukada, M. Ukai, K. Futatsukawa, K. Hosomi, M. Kawai, M. Mimori, N. Terada, N. Maruyama KEK: K. Aoki, H. Fujioka, Y. Kakiguchi, T. Nagae, D. Nakajima, H. Noumi, T. Takahashi, T.N. Takahashi, A. Toyota China Institute of Atomic Energy: Y.Y. Fu, S.H. Zhou Kyoto Univ.: M. Dairaku, K. Miwa Osaka E.C. Univ. : T. Fukuda, S. Minami, W. Imoto Osaka Univ.: S. Ajimura RIKEN: K. Tanida

3. Oct. 13 th 2006Hyp06 Background  interaction (interaction parameters)  Physics interests of the present experiment Experimental setup & analysis  Magnetic spectrometer & Missing mass analysis  Hyperball2 apparatus & gamma-ray spectrum analysis Preliminary results & discussion Summary Outline of the presentation

4. Oct. 13 th 2006Hyp06 Central forceSpin-spin force Tensor force N spin-dependent spin-orbit force spin-dependent spin-orbit force Background: ΛN interaction

5. Oct. 13 th 2006Hyp06 Physics interests of the present experiment can be employed to cross check the parameters. can help to solve the puzzle. Itonaga & Millener's calculation

6. Oct. 13 th 2006Hyp06 (, ) / Experimental setup: overview Totally

7. Oct. 13 th 2006Hyp06 Experimental setup & analysis: track reconstruction Momentum of pion

8. Oct. 13 th 2006Hyp06 BGO suppression Ge efficiency Experimental setup & analysis : Ge detectors  Photoelectric peak efficiency ~5 % @ 1.33 MeV when beam off  Energy resolution = 5.3 keV (FWHM) @ 1.33 MeV when beam on  Time resolution = 18 ns (FWHM) @ 1.33 MeV when beam on

9. Oct. 13 th 2006Hyp06 Preliminary results: states selection

10. Oct. 13 th 2006Hyp06 Preliminary results: gamma rays from Λ B 11

11. Oct. 13 th 2006Hyp06 Preliminary results: gamma rays from Λ C 12 2377

12. Oct. 13 th 2006Hyp06 Discussion 1020 keV 418 keV 2443 keV SNSN SNSN Δ

13. Oct. 13 th 2006Hyp06 Summary KEK-E566: C (pi+, K+) / @ K6 beam line, KEK Three hypernuclear gamma-ray peaks were observed. Two interaction parameters were derived from proper transitions. S N : -0.7~-0.9 MeV Δ : 0.3 MeV Summary S N : ~-0.4 MeV Δ: ~0.43 MeV ΛCΛC 12 ΛBΛB 11

14. Oct. 13 th 2006Hyp06

15. Oct. 13 th 2006Hyp06 Present problems & future task Production rate of the ground state hypernucleus is rather different from previous data.  Other experiments show that the production rate of the ground state is about 7 counts/(g/cm )(10 pion)  In our current analysis this value is ~ 2.3 counts/(g/cm )(10 pion) 29 29 9 9 2 2

16. Oct. 13 th 2006Hyp06 Candidate for ground state doublet transition of  Gamma-ray energy is around 150 keV  Number of counts is consistent with rough estimated value Present problems & future task

17. Oct. 13 th 2006Hyp06 Clover Ge add back Ge calibration Photo-peak efficiency increased by 1.5 times Experimental setup & analysis : Ge detectors

18. Oct. 13 th 2006Hyp06

19. Oct. 13 th 2006Hyp06 Background: Physics interests of the present experiment To measure the g-factor of a hyperon inside nuclear medium. Doppler Shift Attenuation Method (DSAM)

20. Oct. 13 th 2006Hyp06 N1N1 N1N1 N2N2 N2N2 N N N N N NN N N N Background: ΛN interaction