1. N* analysis at the Excited Baryon Analysis Center of JLab Hiroyuki Kamano (EBAC, Jefferson Lab) CLAS12 2 nd European Workshop, March 7-11, Paris, France

2. Objectives and goals: Through the comprehensive analysis of world data of  N,  N, N(e,e’) reactions, Determine N* spectrum (pole positions) Extract N* form factors (e.g., N-N* e.m. transition form factors) Provide reaction mechanism information necessary for interpreting N* spectrum, structures and dynamical origins Excited Baryon Analysis Center (EBAC) of Jefferson Lab N* properties QCDQCDQCDQCD Lattice QCDHadron Models Dynamical Coupled-Channels Analysis @ EBAC Reaction Data http://ebac-theory.jlab.org/ Founded in January 2006 “Dynamical coupled-channels model of meson production reactions” A. Matsuyama, T. Sato, T.-S.H. Lee Phys. Rep. 439 (2007) 193

3. Partial wave (LSJ) amplitude of a  b reaction: Reaction channels: Transition potentials: coupled-channels effect Dynamical coupled-channels model exchange potentials of ground state mesons and baryons exchange potentials of ground state mesons and baryons bare N* states For details see Matsuyama, Sato, Lee, Phys. Rep. 439,193 (2007)

4. Strategy for N* study at EBAC Stage 3 Make a connection to hadron structure calculations; Explore the structure of the N* states.  Quark models, Dyson-Schwinger approaches, Holographic QCD,… Stage 1 Construct a reaction model through the comprehensive analysis of meson production reactions Stage 2  N* spectrum (poles); N*   N, MB transition form factors (residues)  Confirm/reject N* with low-star status; Search for new N* Extract resonance information from the constructed reaction model Requires careful analytic continuation of amplitudes to complex energy plane  Suzuki, Sato, Lee PRC79 025205; PRC82 045206

5. EBAC-DCC analysis (2006-2009)  N   N : Used for constructing a hadronic model up to W = 2 GeV. Julia-Diaz, Lee, Matsuyama, Sato, PRC76 065201 (2007)  N   N : Used for constructing a hadronic model up to W = 2 GeV Durand, Julia-Diaz, Lee, Saghai, Sato, PRC78 025204 (2008)  N    N : First fully dynamical coupled-channels calculation up to W = 2 GeV. Kamano, Julia-Diaz, Lee, Matsuyama, Sato, PRC79 025206 (2009)   N   N : Used for constructing a E.M. model up to W = 1.6 GeV and Q 2 = 1.5 GeV 2 (photoproduction) Julia-Diaz, Lee, Matsuyama, Sato, Smith, PRC77 045205 (2008) (electroproduction) Julia-Diaz, Kamano, Lee, Matsuyama, Sato, Suzuki, PRC80 025207 (2009)  N    N : First fully dynamical coupled-channels calculation up to W = 1.5 GeV. Kamano, Julia-Diaz, Lee, Matsuyama, Sato, PRC80 065203 (2009) Hadronic part Electromagnetic part  N,  N,  N ( ,  N,  N) coupled- channels calculations were performed.  N,  N,  N ( ,  N,  N) coupled- channels calculations were performed.

6. Dynamical coupled-channels effect on N* poles and form factors Pole positions and dynamical origin of P11 resonances Suzuki, Julia-Diaz, Kamano, Lee, Matsuyama, Sato, PRL104 065203 (2010) Suzuki, Sato, Lee, PRC82 045206 (2010) pole A:  unphys. sheet pole B:  phys. sheet

7. Dynamical coupled-channels effect on N* poles and form factors Suzuki, Julia-Diaz, Kamano, Lee, Matsuyama, Sato, PRL104 065203 (2010) Suzuki, Sato, Lee, PRC82 045206 (2010) Nucleon - 1 st D13 e.m. transition form factors Real partImaginary part Crucial role of non-trivial multi-channel reaction mechanisms for interpreting the structures and dynamical origins of nucleon resonances !

8. EBAC-DCC analysis: 2010 ~  N   N  N   N  N   N  N   N  N  KY  N  K  2006 ~ 2009 5 channels (  N,  N, ,  N,  N) < 2 GeV < 1.6 GeV < 2 GeV ― 2010 ~ 7 channels (  N,  N, ,  N,  N,K ,K  ) < 2.1 GeV < 2 GeV < 2.1 GeV # of coupled channels Fully combined analysis of  N,  N   N,  N, KY reactions !!

9. Pion-nucleon elastic scattering Current model preliminary (fully combined analysis, preliminary ) Previous model (fitted to  N   N data only) [PRC76 065201 (2007)] Target polarization 1234 MeV 1449 MeV 1678 MeV 1900 MeV Angular distribution

10. Single pion photoproduction Current model preliminary (fully combined analysis, preliminary ) up to 1.6 GeV Previous model (fitted to  N   N data up to 1.6 GeV ) [PRC77 045205 (2008)] Angular distribution Photon asymmetry 1137 MeV1232 MeV 1334 MeV 1462 MeV1527 MeV1617 MeV 1729 MeV1834 MeV1958 MeV 1137 MeV1232 MeV1334 MeV 1462 MeV1527 MeV1617 MeV 1729 MeV1834 MeV1958 MeV Preliminary!! 1154 MeV1232 MeV1313 MeV 1416 MeV1519 MeV1617 MeV 1690 MeV1798 MeV 1899 MeV 1154 MeV1232 MeV1313 MeV 1416 MeV 1519 MeV1617 MeV 1690 MeV 1798 MeV1899 MeV

11. 1535 MeV 1674 MeV 1811 MeV 1930 MeV 1549 MeV 1657 MeV 1787 MeV 1896 MeV Eta production reactions Preliminary!! Analyzed data up to W = 2 GeV.   p   n data are selected following Durand et al. PRC78 025204. Photon asymmetry

12. pi N  KY reactions Preliminary!! Angular distribution Recoil polarization 1732 MeV 1845 MeV 1985 MeV 2031 MeV 1757 MeV 1879 MeV 1966 MeV 2059 MeV 1792 MeV 1879 MeV 1966 MeV 2059 MeV 1732 MeV 1845 MeV 1985 MeV 2031 MeV 1757 MeV 1879 MeV 1966 MeV 2059 MeV 1792 MeV 1879 MeV 1966 MeV 2059 MeV

13. gamma p  K+ Lambda Preliminary!! 1781 MeV1883 MeV2041 MeV

14. Potential impact of the complete experiments Sandorfi, Hoblit, Kamano, Lee arXiv:1010.0455 Observables of pseudoscalar photoproduction reactions  Take real and imaginary parts of amplitudes as parameters at each energy point  Monte Carlo sampling of L = 0 - 3 amplitudes (up to 10 7 per energy) + gradient minimization Energy-independent multipole analysis of the existing  p  K +  data: = Data available for  p  K + 

15. Potential impact of the complete experiments Sandorfi, Hoblit, Kamano, Lee arXiv:1010.0455 Bands of the best 300 multipole solutions Overall phase is fixed by setting E0+ real. Wide solution bands with tightly clustered  2  Solutions are indistinguishable within the existing data. Real part Imaginary part  0.05  0.03  0.10  0.08  0.18 Difference between Best and Largest  2 E0+ M1+ To narrow the bands,  should increase statistics of the 8 observables ?? OR  should measure all the remaining polarization observables ?? Generate mock data with kinematics and errors expected in the CLAS experiments and repeat the analysis

16. W = 1900 MeV (Energy-independent fit to mock data) Sandorfi, Hoblit, Kamano, Lee arXiv:1010.0455 Potential impact of the complete experiments  2 / data = 0.6 (best  2 solution)  2 / data = 1.4 (largest  2 solution in the best 300 solutions) [Note: Central values of data are generated with the (Gaussian-smeared) Bonn-Gatchina amplitudes.]

17. Potential impact of the complete experiments Sandorfi, Hoblit, Kamano, Lee arXiv:1010.0455 Fit to the existing data of 8 observables Fit to mock data of all 16 observables “Complete experiments” at CLAS A crucial source for determining amplitudes and establishing N* spectrum !!

18. Summary and outlook Fully combined analysis of  N,  N   N,  N, KY reactions is underway.  Re-examine resonance poles  Analyze CLAS ep  e  N data with Q 2 < ~4 GeV 2 ; extract N-N* e.m. transition f.f.s  Include  N,  N   N,  N, … reactions to the combined analysis. Previous model: Q 2 < 1.5 GeV 2 New direction Application of the DCC approach to meson physics: (3-body unitarity effect are fully taken into account) Dalitz plot of  2 (2100)   decay from our model Dalitz plot of  2 (2100)   decay from our model f0, ,..  B, D, J/ ... Heavy meson decays pp  X Exotic hybrids? GlueX Nakamura, arXiv:1102.5753 Kamano, Nakamura, Lee, Sato, in preparation