Workshop on “Extractions and interpretations of hadron resonances and multi-meson production reactions with 12 GeV upgrade”, May 27-28, 2010 Cascade Baryons: Spectrum and production in photon-nucleon reactions Yongseok Oh (Kyungpook National University, Korea)

EBAC Workshop, JLab 2 Overview

EBAC Workshop, JLab 3 1. Introduction

EBAC Workshop, JLab 4 Baryons in SU(3) Baryon octetBaryon decuplet

EBAC Workshop, JLab 5 1. Introduction

EBAC Workshop, JLab 6  in PDG What do we know about  baryons? Particle Data Group (2008): 11  ’ s P is not directly measured

EBAC Workshop, JLab 7 1. Introduction

EBAC Workshop, JLab 8 Advantages Difficulties PDG 2008

EBAC Workshop, JLab 9 1. Introduction

EBAC Workshop, JLab 10 Experiments WA89 (CERN-SPS) EPJC, 11 (1999), hep-ex/

EBAC Workshop, JLab 11 PRC 71 (2005)PRC 76 (2007)

EBAC Workshop, JLab 12 Questions PDG 2008 The 3 rd lowest state CLAS: PRC 76 (2007)

EBAC Workshop, JLab 13 Classify the states as members of octet or decuplet Use spin-parity (if known) and Gell-Mann—Okubo mass relation Works before 1975: reviewed by Samlos, Goldberg, Meadows RMP 46 (1974) Recent work along this line Guzey & Polyakov, hep-ph/ (2005) No dynamics Direct extension of the classification in the quark model Hadron models for  baryons

EBAC Workshop, JLab 14 Nonrelativistic quark model Chao, Isgur, Karl PRD 23 (1981) from S. Capstick The 3 rd lowest state at 1695 MeV? The 3 rd lowest state at 1695 MeV?

EBAC Workshop, JLab 15 Relativistic quark model Capstick, Isgur PRD 34 (1986) from S. Capstick The 3 rd lowest state ?

EBAC Workshop, JLab 16 One-boson exchange model Glozman, Riska Phys. Rep 268 (1996) from S. Capstick The 3 rd lowest state ?

EBAC Workshop, JLab 17

EBAC Workshop, JLab 18 The 3 rd lowest state ? from J.L. Goity

EBAC Workshop, JLab 19 Summary QM (Pervin, Roberts) PRC (expt.) 1320 (expt.) 1530 (expt.) : the 3 rd lowest state

EBAC Workshop, JLab 20 Summary Highly model-dependent !

EBAC Workshop, JLab 21 Skyrme model bound kaon SU(3) is badly broken Treat light flavors and strangeness on the different footing L = L SU(2) + L K/K* Soliton provides background potential which traps K/K* (or heavy) meson Bound state approach (Callan, Klebanov)

EBAC Workshop, JLab 22 Bound state model 270 MeV energy difference Includes parameters They should be computed with a given Lagrangian (dynamics). Or fix them to known masses and then predict. Mass formula

EBAC Workshop, JLab 23 Hyperon spectrum (expt.) 289 MeV 290 MeV 285 MeV positive parity negative parity parity undetermined

EBAC Workshop, JLab 24 Hyperon spectrum (Skyrme model) YO, PRD 75 (2007) spin-parity Recently confirmed by COSY PRL 96 (2006) High precision experiments are required!  ’s would be discovered in future.

EBAC Workshop, JLab 25 More comments Other approaches

EBAC Workshop, JLab 26

EBAC Workshop, JLab 27 Forbidden or suppressed mechanisms

EBAC Workshop, JLab 28 Considered diagrams + exchanged diagrams q 1 q 2

EBAC Workshop, JLab 29 Methods

EBAC Workshop, JLab 30 Intermediate hyperons Particle Data Group Decay widths (and couplings) are in a very wide range. No information for the other couplings.

EBAC Workshop, JLab 31 Total cross section CLAS: PRC 76 (2007)

EBAC Workshop, JLab 32 Differential cross sections

EBAC Workshop, JLab 33 No structure

EBAC Workshop, JLab 34 NOT from a resonance Needs higher-mass resonances More works are needed! Needs higher-mass resonances More works are needed!

EBAC Workshop, JLab Outlook

EBAC Workshop, JLab 36 Preliminary