Satoshi N Nakamura Tohoku University HUGS 2010 Lecture June Jefferson Lab. Day 3 : #5 and #6

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1 Satoshi N Nakamura Tohoku University HUGS 2010 Lecture June Jefferson Lab Day 3 : #5 and #6

2 g-ray spectroscopy Weak-decay p spectroscopy

3 Produce HY by (p,k) or (K, p) reaction : Resolution of MM is irrelevant Just tag the hypernuclear states Measure gray from hypernucleus de-excitation with Ge detector.

4 Twobody LN potential Integrate for configuration of {s 4 p A-5 } s L with core wave function based on Cohen-Kurath wave functions V, S, S, N T, L D.J.Millener, A.Gal, C.B.Dover, R.H.Dalitz, PRC 31(1985) O Heaviest p-shell nucleus 1p 1/2 1p 3/2 1s 1/2

5 Twobody LN potential Integrate for configuration of {s 4 p A-5 } s L with core wave function based on Cohen-Kurath wave functions V, S, S, N T, L 16 L O Heaviest p-shell nucleus D.J.Millener, A.Gal, C.B.Dover, R.H.Dalitz, PRC 31(1985)499. 1p 1/2 1p 3/2 L 1s 1/2 Core nucleus ( 15 O) L

6 Low-lying levels of L hypernucleus V contributes to B L S N Level spacing: linear combination of, S L, S N,T 1) Core transition (a few MeV) 2) L spin-flip transition (< MeV) 3) L inter-shell transition (p L -> s L ) (~10MeV)

7 (e,e K + ) p Λ Mirror Hypernuclei (K,pg) n Λ Good resolution (~400keV) for absolute BE incl. nucleon unbound Thin enriched targets medium-heavy hypernuclei Excellent resolution (~2 kev) for level differences of bound states Spin dependent LN interaction for light hypernuclei Complementary techniques to study hypernuclei

8 Hyperball2 Developed by H. Tamura (Tohoku U.)

9 2keV 1MeV 14 n-type co-axial Ge detectors (70mmf x 70mm) + Compton suppressers (BGO crystal)

10 2x10 6 p + on g/cm 2 thick target

11 Missing Mass spectrum by SKS Tag the bound region of 7 L Li Measure g-decay of 7 L Li.

12 p g K A L Z

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15 Doppler broadening sensitive to lifetime of hypernuclear excited state. t Doppler shift attenuation method 0.9 ( 7 Li, 5/2 ) 5.8 ( stat) 0.7( sys) ps L 0.7

16 t 0.9 ( 7 Li, 5/2 ) 5.8 ( stat) 0.7( sys) ps L 0.7 Tanida et al. PRL86(2001)1982 Branching ratio of E2(5/2 + 1/2 + )= % B Weak decay 2.6% 0.5 ( 7 ) 2 4 E2; Li 5/2 1/ e fm L Reduced transition probability Size shrinkage factor 9 B S 7 ( 7 E2; ) LLi 5/2 1/2 ( 6 B E2; Li 3 1 ) 1/ First direct observation of nuclear size change by impurity. B 3.6% ( E2; Li 3 1 ) e fm L makes 19% shrinkage 7 6 L Li

17 -B L (MeV) Counts/ 10 kev KEK E566: Hyperball2 + SKS JLab E01-011: HKS+ENGE g-transition Level difference 3 kev ±2.8 (stat) kev w/ Doppler correction s L states region E g (kev) (e,e K) Absolute E E g.s ~ 300 kev

18 Measured g-rays from hypernuclei

19 Measured g-rays from hypernuclei Hall C-WS 2007Tamura S N : consistent S L = MeV < 0.3 MeV E = 0.70S N, S L, T: consistent S N = -0.9 MeV S N = MeV = 0.43 MeV E = S L T, S L, S N, T determined. Consistency almost OK. = 0.33 MeV S L : consistent S N = -0.7 MeV E = S L T S N : consistent Effect of SN-LN coupling force? Accuracy of core wave function? S N : consistent = 0.33 MeV T = 0.03 MeV E = S L T

20 Nijmegen meson-exchange models Hall C-WS 2007Tamura spin-spin: = MeV => NSC97f selected (consistent with 4 LH(1 +,0 + ) ) spin-orbit: S L = MeV (SLS+ALS) S N = -0.4 MeV (SLS-ALS) tensor: T = 0.03 MeV => (+ slight adjustment favorable) All Nijmegen models fail QCD inspired quark models OK => Nijmegen models OK S L S N T (MeV) ND NF NSC NSC97f ( Quark ) G-matrix calc. by Yamamoto Strength equivalent to quark-model LS force by Fujiwara et al. Exp L Be aal model Hiyama et al., PRL 85 (2000) 270 Fujiwara et al. Prog.Part.Nucl.Phys.58 (2007) 439.

21 (2009) 52 L V Updated from: O. Hashimoto and H. Tamura, Prog. Part. Nucl. Phys. 57 (2006) 564.

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23 Example: e K + Direct Production e 12 C p 12 L B g.s. Ground state doublet of 12 L B B L and t L 2 - ~150 kev C g.s. p - Weak mesonic two body decay

24 Example: e e 12 C p Fragmentation Process 12L B* K + Access to variety of light and exotic hypernuclei, some of which cannot be produced or measured precisely by other means a a L Fragmentation (<10-16 s) 4 L H L 4 He p - Weak mesonic two body decay (~10-10 s)

25 E.Botta et al. SENDAI08 proc. (2008) Li(K - stop, p- ) 7 L Li P 12 C(K - stop, p- ) 12 L C 12 L C(p) 11 L B + p S 7 Be spectroscopy from: 7 L Li 7 Be + p - Spin/parity: 1/ C spectroscopy from: 11 L B 11 C + p - Spin/parity: 5/2 +?

26 High precision on ground state light hypernuclei Resolution: ~130 kev FWHM; mass precision : < ±30 kev Precise L binding energy Charge symmetry breaking Linkage between structures of hypernuclei and nuclei Determining ground state spin/parity Search for Isomeric low lying states (Isomerism) Study the drip line limit on L-hypernuclei, such as heavy hyper-hydrogen: 6 LH, 7 LH, and 8 LH Medium modification of baryon property B(M1) from lifetime of ground and low lying isomeric states of hypernuclei

27 To Hall Dump To Hall Dump To a low local power photon local dump dump dump Figure 6. Schematic top view of the experimental configuration for the JLAB hypernuclear decay pion spectroscopy experiment (Hall A). 1.2 GeV/c HES MeV/c Pre-Chicaned Electron Beam 2.3 GeV Hall Z-axis C Z-axis p - 22mg/cm 2 K + Schematic Top View of New Hypernuclear 64mg/cm 2 Decay Tagging System at Jlab

28 Septum K + e Lucite Č p - Hodoscope e Drift Chamber Trigger -I: HRS(K) Enge(p) - Decay Pion Experiment Trigger- II: HRS(K) HRS(e ) - Spectroscopy Experiment

29 e g HKS HES Drift Chamber Hodoscope Cherenkov p spectrometer (also serve as SPL) electron beam from CEBAF (E= pass for 12GeV)

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31 Information on LL force : Double L hypernuclei ) ( ) ( ) ( 2 ) ( 2 ) ( ) ( Z M Z M Z M Z B Z B Z B A A A A A A LL L L L LL LL LL LL Existence of H-dibaryon (J P =0 + )?? S-wave flavour-singlet dihyperon at 2150MeV. PRL 38(1977)195. L LL L m H M m 2 ) ( - B 2

32 p(k,k ) X - X - (d s s) KEK-PS E373 A LL Z A' LL Z' From Nakazawa s talk at SNP04

33 H.Takahashi et al., PRL 87 (2001)212502

34 B B LL LL MeV MeV m( H) /(MeV/ c 2 )

35 So far only 4 SHe is known to be bound. 4 He (stopped K -, p - ) 4 He (stopped K -, p + ) S p n R.S.Hayano et al. PLB 231 (1989) 355 S p n I = 1/2 & 3/2 for S=0 Only I = 3/2 for S=0 At 268MeV peak Severe in-flight S decay background

36 T.Nagae et al. PRL 80(1998) B Consistent with stopped K exp. S ( stat) 1( sys) MeV ( stat) ~ 100b/sr ( sys) MeV p - : I = 1/2 & 3/2 for S=0 p + : I = 3/2 for S=0 4 S He : Dominate I=1/2 for S=0 In-flight S decay is highly suppressed

37 Theoretical Prediction : T.Harada et al. NP A507 (1990) 715. Vˆ ˆ C S SNk k1 ( ) 0 CS R U fcfsr U P TS f f R 3 : Isospin( T),Spin( S) imaginary T=1/2 projection real ( R) U T operator T=3/2 ( R)( T B S C t S ) ( stat) 1( sys) MeV ( stat) ~ 100b/sr Lane s term Not for L potential Experimental result T.Nagae et al. PRL 80(1998) ( sys) MeV Strong Lane s term make 4 SHe bound. Central repulsion surpresses SN->LN imaginary

38 Tokai, Japan Material and Biological Science Facility 50 (30) GeV Synchrotron (15 A) 400 MeV Linac (350m) 3 GeV Synchrotron (333 A) Neutrino Facility Hadron Hall 60m x 56m orld-highest beam intensity : ~1 MW 10 of BNL-AGS, x100 of KEK-PS

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40 SKS Hyperball-J Beam Dump Handron Hall K1.8BR K1.8 Hyperball2 (2005~) -> Hyperball-J KL 30~50 GeV primary beam production target (T1) T1 target K0.8 C-type K1.1 S-type E13: g L in nucleus, CSB in LN int. K beam was already delivered to K1.8 BR, K1.8

41 s u u d u K - p X - s s d s u K + High intensity K - beam + Kaon double charge exchange reaction

42 J-PARC-E05 395A 2.7 T Day-1 1 st priority Experiment SKS spectrometer K - + p -> X - + K + K GeV/c First spectroscopy of s=-2 First step to strange matter 1.8 GeV/c K - K1.8 beamline spectrometer

43 Expected Spectrum (4 weeks beam) s X p X V = -20MeV -B X [MeV] V = -14MeV Information on LN interaction XN interaction

44 E13 : Gamma-ray spectroscopy of light hypernuclei (HYPERBALL-J) 7 L Li : g L in a nucleus from spin-flip B(M1) 4 L He, 10 LB, 11 LB, 19 LF : Consistency of LN spin-dependent force, LN-SN coupling, CSB E10 : Study of L hypernuclei with the Double Charge exchange reaction pp(p -,K + )Ln Neutron rich hypernuclei like 6 LH, 9 LHe E07 : Hybrid emulsion for double strangeness system Aiming ~100 of LL events

45 n (g,k 0 ELPH-Tohoku NKS2 Spectrometer : K 0 s p p, Lpp MAMI-C p(e,e K )L hypernuclear decay p spectroscopy (e,e K + ) hypernuclear spectroscopy GSI RI beam + HY decay products measurement GSI-FAIR (Facility for Antip&Ion Research) pp X X, pn X X 0

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48 P. Achenbach s SENDAI08

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50 H.Nemura et al., PLB 673 (2009) 136.

51 Study of Hypernuclei : Baryon interaction on SU(3) sym Bridge between QCD (quark) and phenomenological interaction (baryon) Probe to deep inside of nucleus Modification of nucleus by impurity With meson beam, hypernuclear spectroscopy was established. With (e,e K) reaction, high-resolution reaction spectroscopy is possible. Decay g spectroscopy gave lots of information to YN interaction. Pioneer experiment for decay-p spectroscopy will start soon. Many facilities including J-PARC, Mainz, have hypernuclear programs.