K Imai Exotics 04219 Kyoto Summary of Workshop

K. Imai: Exotics 04/2/19 (Kyoto) Summary of Workshop? K. Imai (Kyoto) n n n It is impossible to summarize all talks More and more data of the peak for Q+ We still don’t know what is Q+ Other exotics are also observed? We need more data and calculations Lets encourage exotics hunters

Sad story of old exotics n n Z* (old pentaquark) magic 15 years cycle Baryonium disappearence of beautiful peak Sextuquark (NN dibaryon) no more phase shift analysis no more stable H-dibaryon Motivation of KEK-PS K 2, K 3 beamlines

Discovery of Lambpha Phys. Rev. Lett. 87 (2001) 212502.

LL Invariant mass C. J. Yoon: new experiment J. K. Ahn et al. , (E 224) Phys. Lett. B 444 (98) 267

Happy story (hopefully) of Q+ M = 1540 10 Me. V G < 25 Me. V Gaussian significance 4. 6 s Renaissance of hadron spectroscopy ! T. Nakano et al. , Phys. Rev. Lett. 91 (2003) 012002 background

Summary of positive results Experiment LEPS/SPring-8 DIANA CLAS(d) SAPHIR ITEP(n) CLAS(p) HERMES ITEP(p) ZEUS Q+ Mass (Me. V) G (Me. V) : 1540 10 5 : 1539 2 few : 1542 2 5 : 1540 4 2 : 1533 5 : 1555 1 10 : 1528 2. 6 2. 1 : 1526 3 3 : 1527+ 2 : 25 : 9 : 21 : 25 : 20 : 26 7 : 19 5 2 : 24 : 23 Y. Mao S. Chekanov

Comparison With Other Experiments For a better comparison, take result from simply BG fitting Left panel: mass average = 1532± 2. 4 Me. V (take ± 3 Me. V of syst. error for ITEP, DIANA) Right panel: width FWHM (include detector resolution) Yajun Mao for HERMES Collaboration, YITP Multi-quark Workshop, Feb. 17 -19, 2004

Increasing number of papers

What is Q+? n n Chiral Soliton Quark model conventional correlated diquark Hadronic bound state Others Jaffe, Lutz, Oka, Ko Hosaka, Kim, Ma, Gerasyuta Theorest’s answer

What is Q+ ? Experimentalists should answer Mass 1526 - 1555 Me. V 1 or 2 resonance Width Upper limit ? 1 Me. V from KN PSA ? Spin-parity 1/2+ 1/2 - 3/2+ 3/2 - ? Other member of anti-decuplet ? we need dedicated experiment at Q+ factory high statistics high resolution Jlab, SP 8, KEK, , , H. Gao, K. I

To establish anti-decuplet n n X- n K- -> K+ X- - , p K- -> K+ p+ X- X+ p K- -> K 0 p- X+ S=-2 Diakonov 2070 Jaffe, Wilczek 1750 n S=0 1710 Me. V 1440 Me. V If M(X--) ~ 1750 Me. V (Jaffe & Wilczek, hep-ph/0307341) >2 Ge. V/c K- beam (BNL or KEK or (J-PARC)) !

S=-2 Penta-quark X-M=1862 Me. V G<18 Me. V IK Yoo （NA 49 collaboration） hep-ex/0310014

“Experimental” data from Lattice QCD A. Nakamura, S. Sasaki, N. Mathur n n 1/2 - is lower than 1/2+ ? Q+ was found ? Yes and No -> need more “ L-QCD experiments”

Quartet quark ? n New data from B-factories Yamamoto / Terasaki, Ko Ds. J D** J/j p+pn Scalar meson Jaffe, Kunihiro, Harada, Nakamura revisit to long standing problem Chiral symmetry diquark correlation Why precise cancellation of attractive and repulsive NN force occur to create human being? Degree of chiral symmetry breaking or diquark correlation or God ?

L(1405) and Kaonic-nuclei Nemoto, Ahn, Hyodo, Akaishi, Yamazaki, Dote n L(1405) another longstanding problem 3 quark or “pentaquark” ? n n Kaonic-nuclei may open new aspect of manybody problem with strangeness New data is coming (after 30 years) Experimental and theoretical works are accelerated by Q+ effect!

Conclusion n n Exciting period for exotic hadron physics has come. We have many thing to do in next 15 years until exotics becomes nonexotic physics.

謝辞 Thank you very much for joining this workshop ! A lot of thanks to supporting staffs, Ms. Tsuruhara, Takami, Yagi, Okada, Arimoto, Endo Mr. Takimi, Nawa Kojo, Tsumura, Kitazawa