Hypernuclear g-ray spectroscopy at J-PARC. Department of Physics, Tohouku University Takeshi Koike

Transcription

1 Hypernuclear g-ray spectroscopy at J-PARC Department of Physics, Tohouku University Takeshi Koike

2

3 Can be probed by hypernuclear g- ray spectroscopy bridging different hierarchical levels in strong sector with a few kev sensitivity

4 Introduction Contents Interesting and important aspects of hypernuclei Hypernuclear g-ray spectroscopy Recent results from E566 analysis: 11 LB and 12 LC The first g-ray spectroscopy at J-PARC : E13 J-PARC and Hyperball-J

5 Nuclear physics with strange quarks +2/3e u (p) ~ Gev c (harm) ~ 1.3 GeV t (op) ~ 171 GeV Nucleons (N) Hyperons (Y) -1/3e S=0 S=-1 S=-2 d (own) ~ GeV S - d s d n d u d s (trange) ~ 0.01 GeV d s s L u s d S 0 p u d u u s s X - X 0 b (eauty) ~ 4.3 GeV u s u S + nucleus hyper nucleus

6 Nuclear force Quark Pion Unified understanding NN to full SU f (3) baryonbaryon interaction NN, YN, YY Lack of NY and YY scattering data without hyperon beams Investigations via hypernuclear properties L hypernuclei LN, SN, LL X hypernuclei XN (J-PARC) N. Ishii, S. Aoki, T. Hatsuda Phys. Rev. Lett. 99, (2007)

7 Production of L hypernucleus, J-PARC K - +n L+p - Strangeness exchange small momentum transfer substitutional secondary beam p + +n L+K + Associated stranegeness production large momentum transfer stretched, high spin secondary beam e+p L+e +K + Electro production spin-flip primary beam

8 Based on L Hypernuclear chart (2010) 16 L O 18 L O 14 L N 15 LN Z 8 12 L C 13 LC 14 LC 9 L B 10 LB 11 LB 12 LB 7 L Be 8 L Be 9 L Be 10 L Be 6 L Li 7 L Li 8 L Li 9 L Li 10 L Li 4 L He 5 L He 6 8 L He 7 LHe L He 3 L H 4 L H 40 L Ca 20<Z L S Emulsion Reaction g-ray spe. 28 L Si 27 L Al 8<Z L Fe 51 L V 52 L V

9 Alice in the strange world : Shell structure Strangeness: a new degree of freedom in nuclear matter No Pauli blocking from nucleons Can occupy any orbits Unique probe of looking deep in the nuclear interior 0g 9/ L39 Y 49 Core excited 1g 9/2 2p 1/2 1f 5/2 2p 3/ n L g f d p s 89 Y(p +,K + ) 89 LY KEK E369 Counter experiment: SKS magnet FWHM= 1.6 MeV Hotchi et al., Phys. Rev. C (2001)

10 2.0 MeV 1/2 - Alice in the strange world : Spin-orbit force np 1/ MeV MeV 1/2-3/2 - Lp 1/2 Lp 3/ /2 + 43keV 5/ C 3/2-0 np 3/2 13 L C Be 9 L Be 1/2 + p 1/2 p 3/2 13 C(K -,p - ) 13 LC BNL E929 g-ray spectroscopy NaI(Tl) array 9 Be(K -,p - ) 9 LBe BNL E930 ( 98) g-ray spectroscopy Ge array (Hyperball) n PRL (2001) PRC (2002) H. Akikawa et al., PRL (2002)

11 Alice in the strange world : Nuclear matter incompressibility 6 Li 7 L Li 7 Li(p +,K + ) 7 LLi KEK E419 g-ray spectroscopy Hyperball Ge array K. Tanida et. al., Phys. Rev. Lett. 86, 1982 (2001) E. Hiyama et. al., Phys. Rev. C 59, 2351 (1999)

12 Hypernuclear g-ray spectroscopy Investigation of strange matter via the EM interactions Most well known forces Model independent extraction of the EM matrix elements B(M1) and B(E2) values Ultra high resolution: 3 kev at 1 MeV g-ray Use of HPGe array Active background suppression Near absolute zero temperature: Bound states: ~ 10 kev to ~ 10 MeV Detection of elementary excitations (NG mode) Property of nuclear g.s. (vacuum)

13 Hyperball and Hyperball2 Hyperball 1998~2004 BNL and KEK Hyperball2 at KEK 2005 E566: last experiment at KEK PS

14 KEK 12 GeV PS K6 beam line October, C(π +, K + ) 12 Λ C/ 11 Λ B+p p p =1.05GeV/c Target: (CH 2 ) n 18.6g/cm 2 Trigger: p + K + = BEAM K Intensity: 3x10 6 /spill 2x10 12 (total p + ) E566 experimental setup Reaction spectrometers: K6/SKS g-ray detector: Hyperball2 + BEAM = egc ( TOF K + = Tof LC AC1 AC2 : BH1& BH 2) 14

15 Missing mass spectrum and selection of states p L states region Y. Ma, Ph.D thesis (2009), Tohoku Univ. 15

16 3 g rays coincident with the p L region E g (7/2 + 5/2 + ) = 262.9±0.2 Assignment of g in 11 LB kev E g (1/2 + 5/2 + ) = ±0.4±0.2 kev 503.9±0.7 kev gg coincidence ±0.4 kev E g (3/2 + 1/2 + ) = 503.9±0.7±0.2 kev observed Also observed in KEK-E518: in KEK-E518: 11 B(π +,, K + ) 11 LB Gate on p L region w/o Doppler correction 262.9±0.2 kev

17 Assignment of g in 12 LC 3 g rays coincident with the s L region w/o w/ Doppler Doppler correction correction ± 6.2 kev E g ( ) = ±5.6±0.3keV E g ( ) = ±2.6±0.3keV E g ( ) = 161.4±0.7±0.3 kev w/o Doppler correction kev

18 LN spin-dependent interaction Two-body effective LN interaction Dalitz and Gal, Ann. Phys. 116 (1978) 167 Millener et al., Phys. Rev. C31 (1985) 499 D: spin-spin S L, S N : spin-orbit T : Tensor Energy levels expressed using these parameters from shell model (weak coupling limit)

19 D = MeV S N = -0.4 MeV S L = 0.01 MeV T = 0.03 MeV As of 2010 M Y. Ma, Ph.D Thesis (2009)

20 KEK & BNL to J-PARC Hyperball to Hyperball-J

21 20 g -ray hypernuclear spectroscopy at J-PARC : E13 2s 1/2 1d 3/2 1d 5/2 19 L F Beyond p-shell terrain 16 L O 8 12 L C 13 L C 15 L N 1p 1/2 10 L B 11 L B Three body SL coupling 9 L Be 2 n 1p 3/2 1s 1/2 7 L Li 4 L He g L in nuclear medium CSB Hyperball 4 L H Hyperball-J (E13)

22 Baryon property in nuclear medium T De-confinement Restoration of chiral symmetry T c Confinement Chiral symmetry breaking q L q R 0 QGP Neutron star r 0 r c r 0 : nuclear matter density Color superconductivity r qq 0 Restoration of chiral symmetry

23 Baryon property in nuclear medium Quark model L = = s e 2m con s c Partial restoration of chiral symmetry in nuclear medium 7 L Li: B(M1) measurement In the weak coupling limit = g L J L + g C J C DSAM 1 3 B( M1) E g B( M1) 2 N J = 3/ 2 J = 1/ 2 2 u d ( g L - g L, g c : Effective g factor of L and core nucleus, respectively J L, J c : Total spin of L and core nucleus, respectively g C ) 2 6 Li 1 + u s d 3/2 + M1 692 kev 1/2 + s

24 Japan Proton Accelerator Research Complex (J-PARC) 400MeV LINAC (350m) 50 GeV synchrotron (15 A) 3 GeV synchrotron (333 A)

25 J-PARC Hadron Hall

26 Hyperball-J J-PARC E13 experimental setup (K -, p - ) p K = 1.5 GeV/c

27 SKS Spectrometer SDC3 SDC4 TOF AC1 AC2 LC BC1 BC2 GC BH1 BH2 BC4 BC3 Q13 Q12 SDC2 SDC1 MS2 K1.8 Beam Spectrometer D4 Q10 Q11 From T. Takahashi, 2010

28 Hyperball-J Hyperball-J Ge array Compact arrangement Ge detector x32 (full set) Total photo peak eff. ~6% for 1-MeV γ ray g-g coincident measurement High modularity Adjustable geometry E13 & E03,07 (X x-ray) R&D Radiation hardness: Mechanical cooling of Ge detector High background: PWO background suppressor High energy deposit and counting rate: Baseline restoration and pile up separation via waveform analysis Half the array shown Planar arrangement

29 Hyperball-J construction snapshots Mechanically cooled Ge detector PWO crystal PWO background suppressor Hyperball-J Frame

30 Summary From NN to baryon-baryon interaction with strangeness and hypernuclei A systematic study of hypernuclear g-ray spectroscopy of the p-shell L hypernuclei with ultra high precision g-ray spectroscopy of light L hypernuclei at J-PARC E13 experiment at J-PARC Measurement of magnetic moment of L in nuclear medium Experiments at J-PARC with a new Ge array Hyperball-J

31 Tohoku University: N.Chiga,Y. Fujii, K. Futatsukawa, O. Hashimoto, K. Hosomi, H. Kanda, M. Kaneta, T. Koike, Y. Ma, K. Maeda, A. Matsumura, K. Miwa, S.N. Nakamura, K. Shirotori, H. Tamura, M. Sato, T. Yamamoto KEK: K. Aoki, T. Haruyama, Y. Kakiguchi, K. Kasami, Y. Sato, M. Sekimoto, H. Takahashi, T. Takahashi, A. Toyoda Joint Institute for Nuclear Research: P. Evtoukhovitch, V. Kalinnikov, W. Kallies, N. Kravchuk, A. Moiseenko, D. Mzhavia, V. Samoilov, Z. Tsamalaidze, O. Zaimidoroga China Institute ofatomic Energy: Y.Y. Fu, C.B. Li, X.M. Li, J. Zhou, S.H. Zhou, L.H. Zhu University of Houston: E.V. Hungerford, A. Lan (+ a postdoc and 2 graduate students) University of Torino and INFN Torino: T. Bressani, S. Bufalino, L. Busso, D. Faso, A. Feliciello, S. Marcello Kyoto University: K. Imai,T. Nagae, H. Fujioka, A. Tokiyasu, M. Motitsu University of Tokyo:, D. Nakajima, T.N. Takahashi Freiburg University: J. Franz, H. Fischer, K. Koenigmann Brookhaven National Laboratory: R.E. Chrien, P. Pile, A. Rusek Florida International University: P. Markowitz, J. Reinhold Gifu University: K. Nakazawa, M. Ukai GSI: S. Minami, T.R. Saito, D. Nakajima ITEP, Russia: A. Krutenkova, V. Kulikov Osaka University: S. Ajimura, H. Noumi Hampton University: L. Tang, L.Yuan INAF-IFSI and INFN Torino: O. Morra Japan Atomic Energy Agency: P.K. Saha Osaka Electro-Communication University: T. Fukuda Pusan University: J.K. Ahn Seoul National University: H.C. Bhang, K. Tanida Torino Polytechnic and INFN: M. Agnello University of New Mexico: B. Bassalleck Hyperball-J collaboration 23 institutes