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KEK 理論センター研究会「原子核・ハドロン物理」 (Aug. 11-13 2009 at KEK). 複素 G 行列を用いた原子核弾性散乱の記述. 古本 猛憲 ( 大阪市立大学理学研究科). 共同研究者 櫻木 千典 ( 大阪市立大学 ) 山本 安夫 ( 都留文科大学 ). Introduction. Optical model potential (OMP) - is complex potential (U=V+iW) - has the imaginary part that represents the loss of flux
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KEK 理論センター研究会「原子核・ハドロン物理」 (Aug. 11-13 2009 at KEK) 複素G行列を用いた原子核弾性散乱の記述 古本 猛憲 (大阪市立大学理学研究科) 共同研究者 櫻木 千典 (大阪市立大学) 山本 安夫 (都留文科大学)
Introduction • Optical model potential (OMP) - is complex potential(U=V+iW) - has the imaginary part that represents the loss of flux in elastic scattering elastic channel • We want a much reliable OMP (real and imaginary parts) • from microscopic view point. non-elastic channel ⇒ imaginary potential
Folding Model approach Single-Folding Model (SFM) Double-Folding Model (DFM) vNN(s) vNN(s) r r2 r1 R Projectile (nucleon) R Target Target Projectile complex G-matrix interaction
Newcomplex G-matrix interaction(CEG07) T.F, Y. Sakuragi and Y. Yamamoto, Phys. Rev. C 78 (2008) 044610 1. derived from ESC04 “ESC04” : the latest version of Extended Soft-Core force designed for NN, YN and YY systems 2. includes Three body force Three-body attraction (TBA) Three-body repulsion (TBR) 3. calculated up to higher density region for the local density prescription in the case of DFM Th. Rijken, Y. Yamamoto, Phys. Rev. C 73 (2006) 044008
1. Three-body attraction (TBA) ・ Fujita-Miyazawa diagram (Δ-resonance) ・ important at low density region effective two-body force three-body force T. Kasahara, Y. Akaishi, and H. Tanaka, Suppl. Prog. Theor. Phys. Vol.56 (1974) 96
2. Three-body repulsion (TBR) ・ universal three-body repulsion (NNN, NNY, NYY) originated the triple-meson correlation ・ important at high-density region Reduction of meson mass in medium MV(ρ)=MV exp(-αρ) for vector mesons In the ESC model ⇒ density-dependent effective two-body force Th. Rijken, Y. Yamamoto, Phys. Rev. C 73 (2006) 044008
New complex G-matrix interaction(CEG07) CEG07b +Three body repulsive (TBR) +Three body attractive (TBA) Decisive role to make the saturation curve realistic CEG07a Two body only
T(s) r R Proton Target Single folding Potential(Central part) Complex G-matrix interaction (CEG07)
T(LS)(s) r R Proton Target Single folding Potential(LS part) Complex G-matrix interaction (CEG07)
Renormalization of the imaginary potential strength fix NW-value to be 0.60 to reproduce the measured total reaction cross sections
Comparison of the folding potential at E = 122 MeV CEG07a(two body only) vs CEG07b(with TBF) TBF effect mainly seen in the real central part
Comparison of the folding potential at E = 122 MeV CEG07a(two body only) vs CEG07b(with TBF) TBF effect This difference appears in analyzing power
Application vNN(s) vNN(s) vNN(s) r r nucleon-nucleus system r2 r1 R R hyperon nucleon R nucleus-nucleus system hyperon-nucleus system
vNN(s) r2 r1 R Projectile(1) Target(2) Double folding Potential Frozen-density approx. (FDA) Complex G-matrix interaction(CEG07)
vNN(s) r2 r1 R Projectile(1) Target(2) Double folding Potential Frozen-density approx. (FDA) Renormalization factor
16O + 16O elastic scattering E/A = 70 MeV Without TBF important effect of three-body force T.F, Y. Sakuragi and Y. Yamamoto, (Phys. Rev. C79 (2009) 011601(R)) T.F, Y. Sakuragi and Y. Yamamoto, (Submitted to Phys. Rev. C.)
Effect of Three-body Attractive force Fujita-Miyazawa diagram T. Kasahara, Y. Akaishi, and H. Tanaka, Suppl. Prog. Theor. Phys. Vol.56 (1974) 96
Effect of Three-body Attractive force Effect of TBA The role of three-body attractive force is minor for nucleus-nucleus scattering T.F, Y. Sakuragi and Y. Yamamoto, (Submitted to Phys. Rev. C.)
Effect of Three-body Repulsive force ・ universal three-body repulsion (NNN, NNY, NYY) originated the triple-meson correlation ・ important at high-density region Reduction of meson mass in medium MV(ρ)=MV exp(-αρ) for vector mesons Th. Rijken, Y. Yamamoto, Phys. Rev. C 73 (2006) 044008
Effect of Three-body Repulsive force Effect of TBR The role of three-body repulsive effect is important for nucleus-nucleus scattering
16O + 12C, 28Si, 40Ca & 12C + 12C elastic scattering important effect of three-body force T.F, Y. Sakuragi and Y. Yamamoto, (Submitted to Phys. Rev. C.)
Summary • We apply SFM & DFM with new complex G-matrix (“CEG07”) • to nucleon-nucleus & nucleus-nucleus elastic scattering • CEG07 is successful • for nucleon-nucleus & nucleus-nucleus elastic scattering • - reproduce cross section & analyzing power data for NA systems • p + 12C, & p and n + 16O systems at various energies. • - reproduce cross section for AA systems • 16O + 12C, 16O, 28Si and 40Ca, & 12C + 12C elastic scattering • at various energies. • CEG07b(with TBF) is apparently better than CEG07a(without TBF) • - mainly due to Three-body repulsive force effect • (three-body attractive effect is minor for nucleus-nucleus reaction)