Dynamical coupled-channels study of hadron resonances and strangeness production Hiroyuki Kamano (RCNP, Osaka U.) in collaboration with B. Julia-Diaz (Barcelona U.), T.-S. H. Lee (Argonne), A. Matsuyama (Shizuoka U.), S. Nakamura (JLab), T. Sato (Osaka U./KEK), N. Suzuki (Osaka U.) Workshop on “Future Prospects of Hadron Physics at J-PARC and Large Scale Computational Physics”, Tokai, Feb. 9-11, 2012

Outline Results of 5-year project on nucleon resonance extraction at Theory projects for strangeness production reactions on the nucleons and nuclei

N* spectroscopy : Physics of broad & overlapped resonances N* : 1440, 1520, 1535, 1650, 1675, 1680,...  : 1600, 1620, 1700, 1750, 1900, … N* : 1440, 1520, 1535, 1650, 1675, 1680,...  : 1600, 1620, 1700, 1750, 1900, … Δ (1232) Width: a few hundred MeV. Resonances are highly overlapped in energy except  (1232). Width: ~10 keV to ~10 MeV Each resonance peak is clearly separated.

Since the late 90s, huge amount of high precision data of meson photo-production reactions on the nucleon target has been reported from electron/photon beam facilities. JLab, MAMI, ELSA, GRAAL, LEPS/SPring-8, … Experimental developments From E. Pasyuk’s talk at Hall-B/EBAC meeting Total cross sections of meson photoproductions Opens a great opportunity to make quantitative study of the N* states !!

Objectives and goals: Through the comprehensive analysis of world data of  N,  N, N(e,e’) reactions, Determine N* spectrum (pole masses) 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 Research project at Excited Baryon Analysis Center (EBAC) of Jefferson Lab N* properties QCDQCDQCDQCD Lattice QCDHadron Models Dynamical Coupled-Channels Analysis Reaction Data “Dynamical coupled-channels model of meson production reactions” A. Matsuyama, T. Sato, T.-S.H. Lee Phys. Rep. 439 (2007) 193

Partial wave (LSJ) amplitudes of a  b reaction: Reaction channels: Transition Potentials: coupled-channels effect Exchange potentials bare N* states For details see Matsuyama, Sato, Lee, Phys. Rep. 439,193 (2007) Z-diagrams Dynamical coupled-channels (DCC) model for meson production reactions Meson-Baryon Green functions Stable channels Quasi 2-body channels N         N N  N N,  s-channel u-channel t-channelcontact Exchange potentials Z-diagrams Bare N* states N* bare   N    N   Can be related with the hadron states of the static hadron structure calculations. (quark models etc.) core meson cloud meson baryon Physical N*s will be a “mixture” of the two pictures:

DCC EBAC ( )  N   N : Analyzed to construct a hadronic part of the model up to W = 2 GeV Julia-Diaz, Lee, Matsuyama, Sato, PRC (2007)  N   N : Analyzed to construct a hadronic part of the model up to W = 2 GeV Durand, Julia-Diaz, Lee, Saghai, Sato, PRC (2008)  N    N : First fully dynamical coupled-channels calculation up to W = 2 GeV Kamano, Julia-Diaz, Lee, Matsuyama, Sato, PRC (2009)   N   N : Analyzed to construct a E.M. part of the model up to W = 1.6 GeV and Q 2 = 1.5 GeV 2 (photoproduction) Julia-Diaz, Lee, Matsuyama, Sato, Smith, PRC (2008) (electroproduction) Julia-Diaz, Kamano, Lee, Matsuyama, Sato, Suzuki, PRC (2009)  N    N : First fully dynamical coupled-channels calculation up to W = 1.5 GeV Kamano, Julia-Diaz, Lee, Matsuyama, Sato, PRC (2009) Extraction of N* pole positions & new interpretation on the dynamical origin of P11 resonances Suzuki, Julia-Diaz, Kamano, Lee, Matsuyama, Sato, PRL (2010) Stability and model dependence of P11 resonance poles extracted from pi N  pi N data Kamano, Nakamura, Lee, Sato, PRC (2010) Extraction of  N  N* electromagnetic transition form factors Suzuki, Sato, Lee, PRC (2009); PRC (2010) Hadronic part Electromagnetic part Extraction of N* parameters  N,  N,  N ( ,  N,  N) coupled-channels calculations were performed.  N,  N,  N ( ,  N,  N) coupled-channels calculations were performed.

Dynamical coupled-channels effect on N* spectrum Pole positions and dynamical origin of P11 resonances Suzuki, Julia-Diaz, Kamano, Lee, Matsuyama, Sato, PRL (2010) pole A:  unphys. sheet pole B:  phys. sheet

Dynamical Coupled-Channels analysis (current status)  p   N  p   N  -p   n  p   p  p  K , K   p  K ,  K  2006 ~ 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 < 2.2 GeV # of coupled channels Fully combined analysis of  N,  N   N,  N, K , K  reactions !! Kamano, Nakamura, Lee, Sato, in preparation

Partial wave amplitudes of pi N scattering Current model (fully combined analysis, PRELIMINALY PRELIMINALY ) Previous model (fitted to  N   N data only) [PRC (2007)] Real partImaginary part Kamano, Nakamura, Lee, Sato in preparation

KY production reactions Preliminary!! 1732 MeV 1845 MeV 1985 MeV 2031 MeV 1757 MeV 1879 MeV 1966 MeV 2059 MeV 1792 MeV 1879 MeV 1966 MeV 2059 MeV Kamano, Nakamura, Lee, Sato in preparation 1781 MeV 1785 MeV

Spectrum of N* resonances Real parts of N* pole values L 2I 2J PRELIMINARY!! PDG 4* PDG 3* Ours Kamano, Nakamura, Lee, Sato in preparation

PRELIMINARY!! Note: Some freedom exists on the definition of partial width from the residue of the amplitudes. Width of N* resonances Kamano, Nakamura, Lee, Sato in preparation

Theory Projects for Strangeness Production Reactions on the Nucleons and Nuclei Participants: Hiroyuki Kamano (RCNP) T.-S. Harry Lee (Argonne Natl. Lab.) Yongseok Oh (Kyungpook U.) Toru Sato (Osaka U. / KEK) Consistent description of production reactions of hyperons and hypernuclei 1 st discussion meeting: Dec Kyungpook U., Korea GOAL

1. Baryon spectroscopy of the strangeness sector Extends DCC approach to analyze Y* production reactions and establish  *,  *, and also  * spectroscopy. K  *,  * N K, , K N, ,  K  *,  * N K  M B (CLAS)  *,  * N K  M B  *,  * K  In photon-induced experiment, one has to analyze four-body production reactions.

2. Determination of YN and YY interactions via pion- and kaon-induced deuteron reactions Y , K N K _ d Y  Y K _ d K Y K N d  Elemental meson-production amplitudes are provided from our dynamical coupled-channels approach.

A Y =  , K K _ A A  K _ A   K 3. Applications to production reactions of hypernuclei Determined YN, YY interactions Many-Body Theory Properties of A Y,YY

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N, N* Meson cloud effect in gamma N  N* form factors G M (Q 2 ) for  N   (1232) transition Note: Most of the available static hadron models give G M (Q 2 ) close to “Bare” form factor. Full Bare

“Static” form factor from DSE-model calculation. (C. Roberts et al) A clue how to connect with static hadron models “Bare” form factor determined from our DCC analysis.  p  Roper e.m. transition

 N   (1232) form factors compared with Lattice QCD data  N   (1232) form factors compared with Lattice QCD data ours

Analysis Database Pion-induced reactions (purely strong reactions) Pion-induced reactions (purely strong reactions) Photo- production reactions Photo- production reactions ~ 28,000 data points to fit The data have been taken by CLAS and will be published soon !!

Partial wave amplitudes of pi N scattering Current model (fully combined analysis, PRELIMINALY PRELIMINALY ) Previous model (fitted to  N   N data only) [PRC (2007)] Real partImaginary part

gamma p  K+ Lambda, K+ Sigma0 Preliminary!! 1781 MeV2041 MeV Polarization observables are calculated using the formulae in Sandorfi, Hoblit, Kamano, Lee, J. Phys. G 38, (2011) 1785 MeV1985 MeV Kamano, Nakamura, Lee, Sato in preparation

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

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 ) [PRC (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!! Kamano, Nakamura, Lee, Sato in preparation

Data handled with the help of R. Arndt pi N  pi pi N reaction Parameters used in the calculation are from  N   N analysis. Kamano, Julia-Diaz, Lee, Matsuyama, Sato, PRC (2009) Full result Phase spaceFull result W (GeV)  (mb) (# of  N   N data) / (# of  N   N data) ~ 1200 / Above W = 1.5 GeV, All  N   N data were measured more than 3 decades ago. No differential cross section data are available for quantitative fits (only the data without error bar exist). (# of  N   N data) / (# of  N   N data) ~ 1200 / Above W = 1.5 GeV, All  N   N data were measured more than 3 decades ago. No differential cross section data are available for quantitative fits (only the data without error bar exist). Need help of hadron beam facilities such as J-PARC !!

Double pion photoproduction Kamano, Julia-Diaz, Lee, Matsuyama, Sato, PRC (2009) Parameters used in the calculation are from  N   N &  N   N analyses. Good description near threshold Reasonable shape of invariant mass distributions Above 1.5 GeV, the total cross sections of p  0  0 and p  +  - overestimate the data.

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. PRC Photon asymmetry

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 ) [PRC (2008)] Angular distribution Photon asymmetry 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

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 Kamano, Nakamura, Lee, Sato in preparation

Single pion electroproduction (Q 2 > 0) Fit to the structure function data (~ 20000) from CLAS Julia-Diaz, Kamano, Lee, Matsuyama, Sato, Suzuki, PRC (2009) p (e,e’  0 ) p W < 1.6 GeV Q 2 < 1.5 (GeV/c) 2 is determined at each Q 2. N*N  (q 2 = -Q 2 ) q N-N* e.m. transition form factor

Single pion electroproduction (Q 2 > 0) Julia-Diaz, Kamano, Lee, Matsuyama, Sato, Suzuki, PRC (2009) p (e,e’  0 ) p p (e,e’  + ) n Five-fold differential cross sections at Q 2 = 0.4 (GeV/c) 2