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Nuclear matter, 2- and 3-body forces and Exotic nuclei in Brueckner Theory Wasi Haider Department of Physics, AMU, Aligarh. Dedicated to Dr J R ROOK and Prof. M Z R Khan Students : S. M. Saliem, B. Sharma, Manjari Sharma, Dipti Pachouri and Syed Rafi. Collaborators : J. R. Rook, P. E. Hodgson, A. M. Kobos, E.D Cooper, K.F Pal, A.M. Street, S. Kailas, Y.K. Gambhir, A. Bhagwat, Hemalatha, J. Blomgren, Zafar A. Khan
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1.Introduction (a) Brief sketch of the theory of Nuclear Matter (effective Interaction) (b) Self consistency (BHF) 2. Binding Energy (symmetric ) (a) Two body force (Coester Band) (b) Three-body force (TBF) (c) Results 3.Nucleon Optical potential (a) Results (Recent) 4.EXOTIC Nuclei. 5.Summary
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Introduction (a) Brief sketch of the theory of Nuclear Matter (effective interaction/G-matrix) Relationship of Nuclear Matter with Nuclear Physics (NP): Main Aim of NP To understand Nuclear Structure in terms of n/p and the strong force among the constituents. One should start from some fundamental Theory- derive the existence and Properties of real nuclei NO SUCH THEORY… Non-Relativistic Schrödinger Eqn. for n/p interacting via the Realistic TWO-Body force (approx.) +3-body force. THIS MANY-BODY PROBLEM IS TOO HARD TO SOLVE
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Nuclear matter (NM) enters as simple FIRST STEP NM is a HYPTHETICAL SYSTEM : No Coulomb force Equal no. of n/p. INFINITE in Coordinate space. Translational Invariance… SPWF = Plane Waves ONLY problem to solve… E/A as f (ρ) and the effective Interaction Saturation Property of Nuclear Force.. E/A(ρ) minimum E 0 at ρ 0. Empirical Estimates of NM Prop = -16 ± 1 (MeV), = 0.17 ± 0.01 Nucl./fm -3 K= 210 ± 30, S= 30.0 ± 3 (MeV) Nuclear Matter theory with TWO-Body force should predict the above properties
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Nuclear EOS Attempt to obtain EOS & OMP from basic Theory (NM) (a) BHF (b) Variational (c) DBHF (Bethe, Brueckner, Gammel, Rajaraman, B. D. Day) Rev. Mod. Phys. 39(1967)719, Rev. Mod. Phys. 39(1967)745. Rajaraman & Bethe(Three Nucleon Correlations) Only input is: NN-interaction + Nucleon Density in Target Nuclei
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Φ 0 = 1/√A! A [ Φ 1 (r 1 )Φ 2 (r 2 )……..Φ A (r A ) ] H 0 Φ 0 = E 0 Φ 0, where E 0 =∑E n H Ψ = E Ψ Goldstone expansion for E E = E 0 + + + …. where P = 1 - Φ 0 > <Φ 0
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FIRST ORDER TERMS: This would diverge as v is highly repulsive at short distances. This is like first Born term: Full Schrodinger equation
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+ + + …..
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Ψ rs (r 1,r 2 ) = Φ rs (r 1,r 2 ) - (Q/e) G(W) Φ rs (r 1,r 2 ). vΨ rs (r 1,r 2 ) = (v - v (Q/e) G(W) ) Φ rs (r 1, r 2 ) = G(W) Φ rs (r 1,r 2 ). Ψ rs (r 1,r 2 ) = Φ rs (r 1,r 2 ) - (Q/e) v Ψ rs (r 1,r 2 ) This is the famous Bethe-Goldstone integral equation.
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Summary The sets of equations suggest that the single particle potential has to be calculated in a self consistent manner. The above choice is called as the Brueckner-Hartree-Fock approximation (BHF). The BINDING ENERGY of NUCLEAR MATTER is then
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The figure shows the level of self- consistancy achieved in about 4-5 cycles (Av-18)
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Results: No TWO-BODY force gives the correct Saturation property of the Symmetric Nuclear Matter. The Goldstone expansion converges rapidly. Hence there is no hope that higher order terms would improve this situation.
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THREE-Body forces are introduced to remedy this situation. URBANA MODEL NPA 401, 59 (1983) NPA 449, 219 (1986) N N N =+ ,, ,, N*N* + A. Lejeune, U. Lombardo, and W. Zuo, Phys. Lett. B 477, 45(2000);
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We need to calculate V S (r), V T (r) and V R (r) and the corresponding defect functions.
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Pure neutron Matter: Results: Symmetry Energy at normal density from different NN-interactions are nearly same and close to the expected result of about 30 MeV.
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Nuclear optical Potential Nucleon Scattering has provided a huge wealth of information about nuclear interaction This Interaction is represented as a single Particle Potential (OPTICAL POTENTIAL): U(E,r)=-V(E,r)-iW(E,r)+V c (r) +(V so (E,r) + iW so (E,r)) Empirically different components are represented in terms of a large no of parameters ( normally 12) It has helped in organizing huge data set, however, there are ambiguities and very small predictive power of this model: DATA: (p,n) Elastic, Reaction & Total cross-section, Polarisation, Spin-Rotation Non Relativistic Mod works upto 200 MeV (A=12-208) Hence the quest to determine it Microscopically starting from the basic NN- interaction using some theory (BHF).
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BHF: 1. AMOS-Group (Non-Local: Bonn) 2. Our-Group (Local: HJ, UV14, Av-14, Av18, Reid93, Nijm II) We solve the radial Bethe Goldstone equation Use BR prescription to define radial G-matrices such that the NM-potential is reproduced. =
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The G-matrices are folded over the nucleon densities to obtain the central and spin-orbit components of the OMP. =
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The real and imaginary central parts for p- 40 Ca (21-400 MeV)
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Decrease of spin-orbit potential as more and more neutrons are added to a nucleus. Predicted weakening of the Spin-Orbit interaction with the addition of Neutrons; M.Hemalatha,Y.K.Gambhir,W.Haider and S.Kailas. Phys. Rev. C79(2009)057602
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Proton scattering from Sn-Isotopes at 295 MeV Microscopic description of 295 MeV polarized protons incident on Sn isotopes. W. Haider, Manjari Sharma, Y. K. Gambhir, and S. Kailas, Phys. Rev. C 81, 034601 (2010).
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Proton scattering from Pb-isotopes at 295 MeV PHYSICAL REVIEW C 84, 037604 (2011) Microscopic description of proton scattering at 295 MeV from Pb isotopes Syed Rafi, Dipti Pachouri, Manjari Sharma, A. Bhagwat, W. Haider, and Y. K. Gambhir
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The first maxima in the spin-orbit force for p-Ni isotopes (52-114) at 65 MeV. The inset shows the neutron skin for the same isotopes. J. Phys. G: Nucl. Part. Phys. 40 (2013) 065101 Syed Rafi, A Bhagwat, W Haider and Y K Gambhir
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Exotic Nucleus: 22 C Recent Reaction Cross-Section. Results for p- 22 C at 40 MeV. K. Tanaka et al. PRL 104 (2010)062701. 19 C………..754(22) mb 20 C………..791(34) mb 22 C………..1338(274) mb Our Brueckner Theory + Glauber Theory results: 22 C……1334 mb Only extended density for the last two neutrons give results in excellent agreement with data. Indicating a Halo structure for 22 C
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The nucleus: 6 He The recent data on polarisation of protons from 6 He at 71 MeV analysed in BHF. The extended neutron density distribution suggests a HALO structure.
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The nucleus: 9 C
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Li Isotopes Syed Rafi, A. Bhagwat,W. Haider and Y. K. Gambhir PHYSICAL REVIEW C 86, 034612 (2012)
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Nucleon Optical potential with Three-Body forces p- 40 Ca at 65 MeV
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p- 40 Ca at 200 MeV
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PHYSICAL REVIEW C 87, 014003 (2013) Syed Rafi,Manjari Sharma,Dipti Pachouri,W. Haider,and Y. K. Gambhir
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List of recently published research papers in refereed journals : 1. Microscopic Optical Model Potentials for p-Nucleus Scattering at Intermediate Energies, M.Hemalatha, Y.K.Gambhir, S.Kailas and W.Haider Phys.Rev.C75(2007)037602 2. Elastic scattering of 96 MeV neutrons from iron, yttrium and lead; A.¨Ohrn, J. Blomgren, P. Andersson, A. Atac, C. Johansson…+ W.Haider; Phys. Rev. C77(2008)024605 3. Predicted weakning of the Spin-Orbit interaction with the addition of Neutrons; M.Hemalatha,Y.K.Gambhir,W.Haider and S.Kailas. Phys. Rev. C79(2009)057602 4. Microscopic Local Optical Potentials and the Nucleon Nucleus Scattering at 65 MeV. W. Haider, Manjari Sharma, IJMPE Vol.19, No 3 465-482 (2010). 5. Microscopic description of 295 MeV polarized protons incident on Sn isotopes. W. Haider, Manjari Sharma, Y. K. Gambhir, and S. Kailas, Phys. Rev. C 81, 034601 (2010). 6. Neutron density distribution and the halo structure of 22 C. Manjari Sharma, A. Bhagwat, Z. A. Khan, W. Haider, and Y. K. Gambhir Phys. Rev C 83, 031601(R) (2011). 7. Microscopic description of protons scattering at 295 MeV from Pb isotopes. Syed Rafi, Dipti Pachouri, Manjari Sharma, Ameeya Bhagwat, W. Haider and Y. K. Gambhir, Phys. Rev. C 84, 037604 (2011). 8. Microscopic Neutron optical potential in the energy region 65-225MeV. Syed Rafi and W.Haider International Journal of Modern Physics E Vol. 20, No. 9 (2011) 2017–2026.
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10. Exact calculation of the Direct part of the nucleon-nucleus spin-orbit potential in Brueckner theory; Dipti Pachouri, Syed Rafi, Manjari Sharma and W.Haider; International Journal of Modern Physics E Vol. 21, No. 2 (2012) 1250010. 11. Microscopic optical potentials for nucleon - nucleus scattering at 65 MeV. Dipti Pachouri, Syed Rafi, W Haider Journal of Physics G: Nuclear and Particle Physics J. Phys. G: Nucl. Part. Phys. 39 (2012) 055101 (18pp) 12.Brueckner-Hartree-Fock based optical potential for proton- 4,6,8 He and proton- 6,7,9,11 Li scattering Syed Rafi, A. Bhagwat, W. Haider, Y.K.Gambhir Phys.Rev. C 86, 034612 (2012) 14. Equation of state and the nucleon optical potential with three-body forces Syed Rafi, Manjari Sharma, Dipti Pachouri, W. Haider and Y. K. Gambhir Phys.Rev. C 87, 014003 (2013). 15. A systematic analysis of microscopic nucleon–nucleus optical potential for p–Ni scattering Syed Rafi, A Bhagwat2, W Haider and Y K Gambhir J. Phys. G: Nucl. Part. Phys. 40 (2013) 065101 9. Microscopic Optical Potential from Argonne inter-nucleon potentials. Dipti Pachouri, Manjari Sharma, Syed Rafi, W. Haider International Journal of Modern Physics E; Vol.20, No.11 (2011)2317-2327.
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