n* analysis at the excited baryon analysis center of jlab
DESCRIPTION
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. “Dynamical coupled-channels model of meson production reactions”. A. Matsuyama, T. Sato, T.-S.H. Lee Phys. Rep. 439 (2007) 193. - PowerPoint PPT PresentationTRANSCRIPT
N* analysis at
the Excited Baryon Analysis Center of JLab
Hiroyuki Kamano
(EBAC, Jefferson Lab)
CLAS12 2nd European Workshop, March 7-11, Paris, France
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
QQCCDD
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”Dynamical coupled-channels model of meson production reactions”
A. Matsuyama, T. Sato, T.-S.H. Lee Phys. Rep. 439 (2007) 193
Partial wave (LSJ) amplitude of a b reaction:
Reaction channels:
Transition potentials:
coupled-channels effect
Dynamical coupled-channels model
exchange potentialsof ground state
mesons and baryons
exchange potentialsof ground state
mesons and baryonsbare N* statesbare N* states
For details see Matsuyama, Sato, Lee, Phys. Rep. 439,193 (2007)
Strategy for N* study at EBAC
Stage 3Stage 3
Make a connection to hadron structure calculations; Explore the structure of the N* states.
Quark models, Dyson-Schwinger approaches, Holographic QCD,…
Stage 1Stage 1
Construct a reaction model through the comprehensive analysis of meson production reactions
Stage 2Stage 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
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 GeVDurand, 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 Q2 = 1.5 GeV2
(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 partHadronic part
Electromagnetic partElectromagnetic part
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* poles and form factors
Pole positions and dynamical origin of P11 resonancesPole 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. sheetpole B: phys. sheet
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 - 1st D13 e.m. transition form factorsNucleon - 1st D13 e.m. transition form factors
Real part Imaginary part
Crucial role of non-trivial multi-channel reaction
mechanisms for interpreting the structures and
dynamical origins of nucleon resonances !
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 GeV
< 2GeV
< 2.1 GeV
< 2.1 GeV
# of coupled channels
Fully combined analysis of N , N N , N , KY reactions !!
Pion-nucleon elastic scattering
Current model
(fully combined analysis, preliminarypreliminary)
Previous model (fitted to N N data only)[PRC76 065201 (2007)]
Target polarizationTarget polarization
1234 MeV1234 MeV
1449 MeV1449 MeV
1678 MeV1678 MeV
1900 MeV1900 MeV
Angular distribution Angular distribution
Single pion photoproduction
Current model (fully combined analysis, preliminarypreliminary)
Previous model (fitted to N N data up to 1.6 GeVup to 1.6 GeV) [PRC77 045205 (2008)]
Angular distribution Angular distribution Photon asymmetry Photon asymmetry
1137 MeV 1232 MeV
1334 MeV
1462 MeV 1527 MeV 1617 MeV
1729 MeV 1834 MeV 1958 MeV
1137 MeV 1232 MeV 1334 MeV
1462 MeV 1527 MeV 1617 MeV
1729 MeV 1834 MeV 1958 MeV
Preliminary!!Preliminary!!
1154 MeV 1232 MeV 1313 MeV
1416 MeV 1519 MeV 1617 MeV
1690 MeV 1798 MeV 1899 MeV
1154 MeV 1232 MeV 1313 MeV
1416 MeV 1519 MeV 1617 MeV
1690 MeV
1798 MeV 1899 MeV
1535 MeV
1674 MeV
1811 MeV
1930 MeV
1549 MeV
1657 MeV
1787 MeV
1896 MeV
Eta production reactions
Preliminary!!Preliminary!!
Analyzed data up to W = 2 GeV. p n data are selected following Durand et al. PRC78 025204.
Photon asymmetry
pi N KY reactions Preliminary!!Preliminary!!
Angular distribution Angular distribution Recoil polarizationRecoil 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
gamma p K+ Lambda
Preliminary!!Preliminary!!1781 MeV 1883 MeV 2041 MeV
Potential impact of the complete experiments
Sandorfi, Hoblit, Kamano, Lee arXiv:1010.0455
Observables of pseudoscalar photoproduction reactions 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 107 per energy)
+ gradient minimization
Energy-independent multipole analysis of the existing p K+ data:
= Data available for p K+
Potential impact of the complete experiments
Sandorfi, Hoblit, Kamano, Lee arXiv:1010.0455
Bands of the best 300 multipole solutionsBands 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
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
W = 1900 MeV (Energy-independent fit to mock data)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.]
Potential impact of the complete experiments
Sandorfi, Hoblit, Kamano, Lee arXiv:1010.0455
Fit to the existing data of 8 observablesFit to the existing data of 8 observables Fit to mock data of all 16 observablesFit to mock data of all 16 observables
“Complete experiments” at CLAS
A crucial source for determining amplitudes and establishing N* spectrum !!
Summary and outlook
Fully combined analysis of N, N N, N, KY reactions is underway.
Re-examine resonance poles
Analyze CLAS ep eN data with Q2 < ~4 GeV2; extract N-N* e.m. transition f.f.s
Include N, N N, N, … reactions to the combined analysis.
Previous model: Q2 < 1.5 GeV2
New directionNew 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
p p
X Exotic hybrids?
GlueX
Nakamura, arXiv:1102.5753 Kamano, Nakamura, Lee, Sato, in preparation