Spectroscopy of Hyperon Resonances and Related Program at J-PARC

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1 Nov , 2016 Spectroscopy of Hyperon Resonances and Related Program at J-PARC Hiroyuki Noumi RCNP, Osaka Univ./IPNS, KEK 1

2 Contents Hyperon resonances below K bar N threshold K bar N interaction L(1405) : a dynamically generated meson-baryon state A role of low energy K bar beams Experiment at the J-PARC K1.8BR BL Further studies on L(1405) Production rate and Form factor L(1405) production in Hard process: quark counting 2

3 Λ(1405) : MeV (PDG) J P = ½ -, I = 0, M L(1405) < M K bar N, lightest in neg. parity baryons S*(1385), 3/2 + L(1520), 3/2 - KN(1432) L(1405), 1/ MeV S(1192), 1/2 + L(1116), 1/2 + M. Hassanvand et al: ps IM Spec. of pp K + ps J. Esmaili et al: ps IM Spec. of Stopped K - on 4 He R.H. Dalitz et al: ps IM Spec. in K-p ππσ w/ M-matrix

4 Λ(1405) : Double pole? J P = ½ -, I = 0, M L(1405) < M K bar N, lightest in neg. parity baryons S*(1385), 3/2 + L(1520), 3/2 - KN(1432) L(1405), 1/ MeV S(1192), 1/2 + L(1116), 1/2 + KN ps Chiral Unitary Model: D. Jido et al., NPA725(03)181

5 Λ(1405) : Need more data? J P = ½ -, I = 0, M L(1405) < M K bar N, lightest in neg. parity baryons pp K + pπ Σ +, K + pπ + Σ L(1520), 3/2 - π Σ + KN(1432) S*(1385), 3/2 + L(1405), 1/ MeV γp K + π Σ +, K + π 0 Σ 0, K + π + Σ S(1192), 1/2 + L(1116), π + Σ 1/2 + CLAS collaboration: PRC87, HADES collaboration: PRC87,

6 Still L(1405)? K bar N int. and its pole position are still unclear. Basic information on Kaonic Nuclei ( H. Ohnishi) Not yet demonstrated if it is a molecular state. To establish it as an exotic state Hadron Picture in excited states New question related to classification in CQM Formation probability in hadronization ExHIC (Phys.Rev. C84 (2011) ) Important role of Low Energy K bar Beams 6

7 Y* - YG.S. [MeV]? L(1830, 5/2 - ) L(1690,?? ) L(1670, 1/2 - ) L(1520, 3/2 - ) L(1405, 1/2 - ) S * (3/2 + ) L(1/2 + ) S(1/2 + ) L(GS) Lambda Baryons (P-wave) s r r l c S c* (3/2 + ) S c (1/2 + ) L c (GS) M Q [GeV/c 2 ] L c (2940,?? ) L c (2880, 5/2 + ) L c or S c (2765,?? ) L c (2625, 3/2 - ) L c (2595, 1/2 - ) b l Q L b (5920, 3/2 - ) L b (5912, 1/2 - ) S b* (3/2 + ) S b (1/2 + ) L b (GS) qq r non-rel. QM:H=H 0 +V conf +V SS +V LS +V T r-l mixing (cal. By T. Yoshida) T. Yoshida et al., Phys. Rev. D92, (2015) 7

8 Still L(1405)? K bar N int. and its pole position are still unclear. Basic information on Kaonic Nuclei ( H. Ohnishi) Not yet demonstrated if it is a molecular state. To establish it as an exotic state Hadron Picture in excited states New question related to classification in CQM Formation probability in hadronization ExHIC (Phys.Rev. C84 (2011) ) Important role of Low Energy K bar Beams 8

9 Spectroscopic Study of Hyperon Resonances below K bar N Threshold via the (K -,n) Reaction on Deuteron the E31 collaboration S. Ajimura 1, H. Asano 1, G. Beer 2, C. Berucci 4, M. Bragadireanu 12, P. Buehler 4, L. Busso 5, M. Cargnelli 4, S. Choi 3, C. Curceanu 8, S. Enomoto 14, D. Faso 5, H. Fujioka 13, Y. Fujiwara 12, T. Fukuda 11, C. Guaraldo 8, T. Hashimoto 9, R. S. Hayano 13, T. Hiraiwa 1, M. Iio 15, M. Iliescu 8, K. Inoue 1, N. Ishibashi 7, Y. Ishiguro 14, T. Ishikawa 13, S. Ishimoto 15, T. Ishiwatari 4, K. Itahashi 9, M. Iwai 15, M. Iwasaki 9,10, S. Kawasaki 1, P. Kienle 16, T. Kim 10, H. Kou 10, Y. Ma 9, J. Marton 4, Y. Matsuda 13, Y. Mizoi 11, O. Morra 5, T. Nagae 14, H. Noumi 1,15, H. Ohnishi 9, S. Okada 9, H. Outa 9, K. Piscicchia 8, M. Poli Lener 8, A. Romero Vidal 8, Y. Sada 1, A. Sakaguchi 7, F. Sakuma 9, M. Sato 9, M. Sekimoto 14, H. Shi 8, K. Shirotori 1, D. Sirghi 8,12, F. Sirghi 8,12, S. Suzuki 15, T. Suzuki 13, H. Tatsuno 8, M. Tokuda 10, D. Tomono 1, A. Toyoda 15, K. Tsukada 17, O. Vazquez Doce 8,18, E. Widmann 4, K. Wuenschek 4, T. Yamaga 1, T. Yamazaki 9,13, K. Yoshida 7, H. Yim 19, J. Zmeskal Research Center for Nuclear Physics, Osaka University, Japan 2. University of Victoria, Canada, 3. Seoul National University, South Korea 4. Stefan Meyer Institut fur subatomare Physik, Austria, 5. INFN Sezione di Torino, Italy, 6.Universita di Torino, Italy 7. Osaka University, Japan, 8. Laboratori Nazionali di Frascati dell INFN, Italy, 9. RIKEN, Japan 10. Tokyo Institute of Technology, Japan, 11. Osaka Electro-Communication University, Japan 11. National Institute of Physics and uclear Engineering, IFIN HH, Romania 13. University of Tokyo, Japan, 14. Kyoto University, Japan 15. High Energy Accelerator Research Organization (KEK), Japan, 16. Technische Universitat Munchen, Germany 17. Tohoku University, Japan, 18. Excellence Cluster Universe, Technische Universitat Munchen, Germany 19. Korea Institute of Radiological and Medical Sciences (KIRAMS), South Korea 9

10 E31 aims at: measuring an S-wave ഥKN πσ scattering below the ഥKN threshold in the d(k -,n)ps reactions at a forward angle of n. K - d N N ഥK n π,0 Σ ±,0 ID s all the final states to decompose the I=0 and 1 ampl s. π ± Σ I=0, 1 L(1405) (I=0, S wave), non-resonant[i=0/1] (S(1385) (I=1, P wave) to be suppressed) π Σ 0 [π Λ] I=1 non-resonant (S(1385) to be suppressed) d(k -,p)p - S 0 [p - L] π 0 Σ 0 I=0 L(1405) (I=0, S wave), non-resonant

11 Experimental Setup for E31 K- d ~0.25 GeV/c L(1405) 1 GeV/c ~1.25 GeV/c S p n p n Beam Sweeper (Ushiwaka) TOF~15m Neutron Counter (NC) BLC1 BHD Cylindrical Detector System (Solenoid Field 0.7T) BLC2 K - Beam Spectrometer (K1.8BR-D5) T0 CDC BPD BPC CDH CDS Ushiwaka Proton Counter (PC) NC PC D5 11

12 Schematic Drawings of Detectors Event topology of d K, n X π ± Σ π (π + ) CDS K T0 n BPD CDC Σ (Σ + ) CDC ~15 m n π + (π ) Solenoid mag. NC 12

13 Particle ID (CDS) π + p π K 13

14 E31 Run Summary E31 run pre May st May-June nd Spring? 2017 Beam Power Beam Time 27 kw 2.2d ~5% Executed/ Proposed 43 kw ~7d ~30% 45 kw (Expected) ~18(+2)d (request) 100% 14

15 d K, nπ + π n missing Gated n nπ 0 n p + K - p - S + CDS n NC n p - K - p + S - CDS n NC Missing Mass of d K, nπ + π [GeV/c 2 ] 15

16 d K, nπ + π "n samples contain Signal Events d K, n X π ± Σ n p + K - p - S + n n p - K - p + S - n Background Events K 0 S - S + p + p - K 0 S S - + p + n K - p - K 0 n n K - S - K - S + p + p - 16

17 d K, n X π ± Σ Spectrum Missing mass spectrum of the d K, n X π ± Σ reaction K 0 and S decay events have been excluded. K p 17

18 Counts/5 MeV π + Σ /π Σ + Mode separation (template fitting) S - S + ps missing mass [GeV/c 2 ] 18

19 d 2 σ (Arbitrary Unit) dωdm πσ π + Σ /π Σ + Mode (I = 0, 1) dσ dω π± Σ = 1 3 f I= f I=1 2 ± 6 3 Re(f I=0f I=1 ) + + π Σ + π + Σ 19

20 d 2 σ (Arbitrary Unit) dωdm πσ π + Σ /π Σ + Mode Average dσ dω av = 1 3 f I= f I=1 2 20

21 d K, p X π Σ0 Mode (I = 1) p - From d K, pπ π "pγ" sample S 0 p K - p - Λ Σ 0 Σ 0 Λ d K, pπ π "p" d K, p X π Λ 21

22 dσ π + Σ /π Σ + Average (I = 0, 1) V.S. π Σ 0 Mode (I = 1) dωdmπσ (Arbitrary Unit) The I=0 amplitude seems dominant. 1 2 π+ Σ + π Σ + ~ 1 3 f I= f I= π Σ 0 ~ 1 2 f I=1 2 22

23 Remarks of E31 1 st Run Structures below and above the ഥKN threshold are observed in d K, n X π ± Σ Interference btw I=0 and 1. Pure I=1 channel, d K, p X π Σ0, is observed. I=0 amp. seems dominant in π ± Σ modes, assuming similarity of the reaction mechanism among d K, n X π ± Σ and d K, p X π Σ 0. 24

24 In E31 2 nd Run To measure a Pure I=0 channel, d K, n X π 0 Σ 0 π CDS K T0 p BPD γ Σ 0 π 0 CDC CDC ~15 m n Solenoid mag. NC 25

25 Counts Counts d K, n X π 0 Σ 0 mode (I=0) Λ γλ pπ K - T0 BPD p g p - S 0 p 0 n s~3.7 MeV/c 2 π 0 π 0 γ (2π) 0 Invariant Mass of pπ [GeV/c 2 ] MM of d K, npπ X [GeV/c 2 ] Promising to measure with higher statistics in the 2 nd Run 26

26 j 0 (qr) exp(-r 2 /b 0 2 ) Further studies on L(1405) Angular dependence of d K, n X (πσ) Sticking probability of ഥK to a residual N I(q; b 0 ) = f(b 0 ) j 0 (qr/ħ) i 2 f b 0 ~Nexp( r 2 /b 0 2 ): S wave final state q: mom. transfer (angular dependent) q=0.25 GeV/c q=0.4 GeV/c b0=2 fm b0=1fm r [fm] b 0 1fm 2fm I (q=0.25 GeV/c) I (q=0.4 GeV/c) ratio The larger b 0, the steeper angular dependence. 27

27 Further studies on L(1405) L(1405) production in Hard process (at large s, t) : quark counting rule: dσ/dω θ=90 o~ 1/s n 2 H. Kawamura, et al. PRD 88, (2013) π + p K + Λ(1405) 28

28 High-res., High-momentum Beam Line 30 GeV proton beam High-intensity secondary Pion beam (unseparated) 1.0 x GeV/c High-resolution beam: Dp/p~0.1% Production Target T1 ITOF DC decay p(p + ) DC RICH DC TOF K + p - Pion Beam Up to 20 GeV/c H 2 TGT Fiber Tracker p s - Spectrometer 29

29 In Summary Low energy K bar beams are useful to study hyperon resonances. In particular, they play important roles on further studies of L(1405) and the K bar N. It is complimentary to other beams, such as high-momentum hadron beams at J-PARC. 30