Study of Excited Nucleon States at Study of Excited Nucleon States at EBAC: Status and Plans EBAC: Status and Plans Hiroyuki Kamano Hiroyuki Kamano (Excited Baryon Analysis Center, Jefferson Lab) (Excited Baryon Analysis Center, Jefferson Lab) in collaboration with in collaboration with B. Julia-Diaz, T.-S. H. Lee, A. Matsuyama, B. Julia-Diaz, T.-S. H. Lee, A. Matsuyama, T. Sato, N. Suzuki T. Sato, N. Suzuki NSTAR 2009, April 19-22, 200
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Study of Excited Nucleon States at EBAC: Status and Plans
Study of Excited Nucleon States at EBAC: Status and Plans. Hiroyuki Kamano (Excited Baryon Analysis Center, Jefferson Lab) in collaboration with B. Julia-Diaz, T.-S. H. Lee, A. Matsuyama, T. Sato, N. Suzuki. NSTAR 2009, April 19-22, 2009. PDG *s and N*’s origin. - PowerPoint PPT Presentation
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Study of Excited Nucleon States at EBAC: Study of Excited Nucleon States at EBAC: Status and PlansStatus and Plans
Hiroyuki KamanoHiroyuki Kamano(Excited Baryon Analysis Center, Jefferson Lab)(Excited Baryon Analysis Center, Jefferson Lab)
in collaboration within collaboration withB. Julia-Diaz, T.-S. H. Lee, A. Matsuyama,B. Julia-Diaz, T.-S. H. Lee, A. Matsuyama,
T. Sato, N. SuzukiT. Sato, N. Suzuki
NSTAR 2009, April 19-22, 2009
Need consistent analysis of
N and N channels
Need consistent analysis of
N and N channels
PDG *s and N*’s origin
Most of their properties are extracted from
Are they all genuine quark/gluon excitations (with meson cloud) ?
Is their origin dynamical ? some could be understood as arising from
A. Matsuyama, T. Sato, T.-S.H. Lee Phys. Rep. 439 (2007) 193
Dynamical coupled-channels model of meson production reactions
Singular!
a
a
Dynamical coupled-channels model @ EBAC
Meson production dataMeson production dataN* spectrum, structure, … N* spectrum, structure, …
Reaction mechanism
Maintain coupled-channels unitarity of
Can treat 3-body unitary cut
Partial wave (LSJ) amplitude of a b reaction:
Reaction channels:
Potential:
coupled-channels effect
Dynamical coupled-channels model @ EBAC
meson exchangemeson exchange bare N* statebare N* state
Impose minimal number of bare N* state: at present16 of 18 (= # of 3* and 4* N*s
below 2 GeV)
Impose minimal number of bare N* state: at present16 of 18 (= # of 3* and 4* N*s
below 2 GeV)
For details see Matsuyama, Sato, Lee, Phys. Rep. 439,193 (2007)
ApplicationApplication
FeedbackFeedback
Pass hadronic parameters Pass hadronic parameters
Application Extract N* N, KY, N
Application
Extract N* N, KY, N
ApplicationApplication
FeedbackFeedback
Extraction of N-N* ele.-mag. transition form factorsExtraction of N-N* ele.-mag. transition form factors
Extraction of N* poles and N* MB decay form factorsExtraction of N* poles and N* MB decay form factors
Strategy for N* study @ EBAC
Fit hadronic part of parameters
Fit electro-magneticpart of parameters
Refit hadronic part of parameters
Refit electro-magneticpart of parameters
Develop a method to connect our f.f.s with hadron structure calculationsDevelop a method to connect our f.f.s with hadron structure calculations
Current status of the analysis @ EBAC
N N : fitted to the SAID PWA up to W = 2 GeV.Julia-Diaz, Lee, Matsuyama, Sato, PRC76 065201 (2007)
N N : cross sections calculated with the N model; fit is not finished.Kamano, Julia-Diaz, Lee, Matsuyama, Sato, PRC79 025206 (2009)
N N : fitted to the data up to W = 2 GeVDurand, Julia-Diaz, Lee, Saghai, Sato, PRC78 025204 (2008)
N N : fitted to the data up to W = 1.6 GeV (and up to Q2 = 1.5 GeV2) (photoproduction) Julia-Diaz, Lee, Matsuyama, Sato, Smith, PRC77 045205 (2008) (electroproduction) Julia-Diaz, Kamano, Lee, Matsuyama, Sato, Suzuki, arXiv:0904.1918