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Photo-productions of Kaons and Hyperons

Photo-productions of Kaons and Hyperons. Atsushi Hosaka, RCNP, Osaka University. Chiral symmetry 1. Gauge inv.: Kroll-Ruderman term  N –> K  (1520),  N –> K  (1520) 2. Tomozawa-Weinberg 2. SU(3) symmetry violation?

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Photo-productions of Kaons and Hyperons

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  1. Photo-productions of Kaons and Hyperons Atsushi Hosaka, RCNP, Osaka University Chiral symmetry 1. Gauge inv.: Kroll-Ruderman term N –> K(1520), N –> K(1520) 2. Tomozawa-Weinberg 2. SU(3) symmetry violation? N –> Kg.s. and the use of polarization 特定領域研究会鳥羽

  2. Effective lagrangian method Good physics intuitions if separated   N Y, Q, … Higher order corrections are classified either one of them 特定領域研究会鳥羽

  3. Strategy Use fundamental symmetry relations as much as possible Chiral, flavor, u-spin, KR-asymmetry and so on Kroll-Ruderman: Proton-neutron asymmetry (2)TW (gV=1) (3) Yukawa: F/D ratio, Decay pattern: (1405) –> KN, , etc (4) U-spin: 8 –> 10 process 特定領域研究会鳥羽

  4. Chiral symmetry 1: Gauge inv.Role of the Kroll-Ruderman term 特定領域研究会鳥羽

  5. present only for charge-exchange reactions Particularly important for J = 3/2 J = 1/2 の場合はそれほどでもない p –> K(1520), n –> K 特定領域研究会鳥羽

  6. gp –> KL(1520) J = 3/2– L = 700 MeV <=> r ~ 0.8 fm t or q dependence Energy dependence Nam-Hosaka-Kim, PRD 71:114012,2005 特定領域研究会鳥羽

  7.  p  +*,  n  +* L = 700 MeV <=> r ~ 0.8 fm  p  0*,  n  –* 特定領域研究会鳥羽

  8. Chiral symmetry 2:Role of the Tomozawa-Weinberg 特定領域研究会鳥羽

  9. TW  K  K Tomozawa-Weinberg (gV=1) (, K) and (K, ) reactions KEK experiments + Tomozawa-Weinberg term Forbidden due to offdiagnality 特定領域研究会鳥羽

  10. Theoretical question PS:Linear sigma model suited to dynamical description for chiral symmetry breaking BUT no convergence in perturbation better large k behavior PV:Non-linear sigma model Good convergence at low momentum • At low energies, PV should be used with FF • Consistent with the low energy theorem Some confusions 特定領域研究会鳥羽

  11. T. Hyodo (YITP) Estimation PS PV PS PV 特定領域研究会鳥羽

  12. 2. SU(3) symmetry violation? 特定領域研究会鳥羽

  13. SU(3) symmetry Current masses: mu, md ~ 10 MeV, ms ~ 100 MeV BUT Constituent masses: mu*, md* ~ 300 MeV, ms* ~ 400 MeV It is likely that SU(3) symmetry is good for basic interactions BUT may break through dynamical effects m << mK => Strongly coupled meson-baryon dynamics Spontaneous breaking of chiral symmetry 特定領域研究会鳥羽

  14. Production of K and (1116) Studied many years: BUT we can learn something essential now Pion production: well known Kaon production: less understood Large ambiguities • Can SU(3) relations be used? • How strongly does the K* couple to N and Y? 特定領域研究会鳥羽

  15. Various couplings Strong Weak 特定領域研究会鳥羽

  16. SAPHIA Total W ~ 2.1 GeV Weak K* ~ SU(3) Strong K* p –> K+ 特定領域研究会鳥羽

  17. Weak K* ~ SU(3) Strong K* p –> K+ E = 1.9 GeV, W ~ 2.1 GeV LEPS  dependence CLAS SAPHIA 特定領域研究会鳥羽

  18. Asymmetry LEPS 0.5 Weak K* ~ SU(3) A Strong K* 0 Asymmetry A - 0.5 p –> K+ E = 1.9 GeV, W ~ 2.1 GeV 特定領域研究会鳥羽

  19. Role of K* Strong K* => pn asymmetry is not so large Weak => could be large due to contact term Information of n-target is very important 特定領域研究会鳥羽

  20. Something is missing? Spin 3/2 Meson clouds Magnetic Anomalous process 特定領域研究会鳥羽

  21. Summary There are many important but not yet well understood physics • Test of chiral symmetry: KR- and TW terms • SU(3) relations holds? Vector meson couplings 特定領域研究会鳥羽

  22. LEPS data -dependence Asymmetry + : K* dominant – : K dominant 特定領域研究会鳥羽

  23.  dependence LEPS CLAS SAPHIA 1.6 2.4 2 Weak K* ~ SU(3) Strong K* p –> K+ Total SAPHIA E = 1.9 GeV, W ~ 2.1 GeV LEPS 特定領域研究会鳥羽

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