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FermiGasy
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W. Udo Schröder, 2005 Angular Momentum Coupling 2 Addition of Angular Momenta
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W. Udo Schröder, 2005 Angular Momentum Coupling 3
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W. Udo Schröder, 2005 Angular Momentum Coupling 4 Constructing J Eigen States Can you show this??
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W. Udo Schröder, 2005 Angular Momentum Coupling 5 Constructing J-1 Eigen States Normalization conditions leave open phase factors choose asymmetrically ≥ 0 and ≤ 0 Condon-Shortley We have this state:
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W. Udo Schröder, 2005 Angular Momentum Coupling 6 Clebsch-Gordan Coefficients
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W. Udo Schröder, 2005 Angular Momentum Coupling 7 Recursion Relations
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W. Udo Schröder, 2005 Angular Momentum Coupling 8 Recursion Relations for CG Coefficients Projecting on <j 1,j 2,m 1,m 2 | yields
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W. Udo Schröder, 2005 Angular Momentum Coupling 9 Symmetries of CG Coefficients Triangular relation Condon-Shortley : Matrix elements of J 1z and J 2z have different signs
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W. Udo Schröder, 2005 Angular Momentum Coupling 10 Explicit Expressions A. R. Edmonds, Angular Momentum in Quantum Mechanics
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W. Udo Schröder, 2005 Angular Momentum Coupling 11 2 Particles in j Shell (jj-Coupling) Which J = j 1 +j 2 (and M) are allowed? antisymmetric WF JM Look for 2-part. wfs of lowest energy in same j-shell, V pair (r 1,r 2 ) < 0 spatially symmetric j1 (r) = j2 (r). Construct consistent spin wf. N = normalization factor
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W. Udo Schröder, 2005 Angular Momentum Coupling 12 Symmetry of 2-Particle WFs in jj Coupling 1)j 1 = j 2 = j half-integer spins J =even wave functions with even 2-p. spin J are antisymmetric wave functions with odd 2-p. spin J are symmetric jj coupling LS coupling equivalent statements 2) l 1 =l 2 =l integer orbital angular momenta L wave functions with even 2-p. L are spatially symmetric wave functions with odd 2-p. L are spatially antisymmetric Antisymmetric function of 2 equivalent nucleons (2 neutrons or 2 protons) in j shell in jj coupling.
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W. Udo Schröder, 2005 Angular Momentum Coupling 13 Tensor and Scalar Products Transforms like a J=0 object = number
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W. Udo Schröder, 2005 Angular Momentum Coupling 14 Example: HF Interaction protons electrons only only
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W. Udo Schröder, 2005 Angular Momentum Coupling 15 Wigner’s 3j Symbols
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W. Udo Schröder, 2005 Angular Momentum Coupling 16 Explicit Formulas Explicit (Racah 1942): All factorials must be ≥ 0
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W. Udo Schröder, 2005 Angular Momentum Coupling 17 Spherical Tensors and Reduced Matrix Elements = Qu. # characterizing states Wigner-Eckart Theorem
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W. Udo Schröder, 2005 Angular Momentum Coupling 18 Wigner-Eckart Theorem Take the simplest ME to calculate
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W. Udo Schröder, 2005 Angular Momentum Coupling 19 Examples for Reduced ME
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W. Udo Schröder, 2005 Angular Momentum Coupling 20 Reduced MEs of Spherical Harmonics Important for the calculation of gamma and particle transition probabilities
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W. Udo Schröder, 2005 Angular Momentum Coupling 21 Isospin Charge independence of nuclear forces neutron and proton states of similar WF symmetry have same energy n, p = nucleons Choose a specific representation in abstract isospin space: Transforms in isospin space like angular momentum in coordinate space use angular momentum formalism for isospin coupling.
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W. Udo Schröder, 2005 Angular Momentum Coupling 22 2-Particle Isospin Coupling Use spin/angular momentum formalism: t (2t+1) iso-projections
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W. Udo Schröder, 2005 Angular Momentum Coupling 23 2-Particle Spin-Isospin Coupling Both nucleons in j shell lowest E states have even J T=1 ! For odd J total isospin T = 0 3 states (M T =-1,0,+1) are degenerate, if what should be true (nn, np forces are same) Different M T states belong to different nuclei T 3 = (N-Z)/2
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W. Udo Schröder, 2005 Angular Momentum Coupling 24 2-Particle Isobaric Analog (Isospin Multiplet) States Corresponding T=1levels in A=14 nuclei T 3 =-1 2n holes T 3 =+ 1 2n T 3 =0, pn
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W. Udo Schröder, 2005 Angular Momentum Coupling 25
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W. Udo Schröder, 2005 Angular Momentum Coupling 26 Separation of Variables: HF Interaction protons electrons only only
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W. Udo Schröder, 2004 Nuclear Deform 27 Electric Quadrupole Moment of Charge Distributions |e|Z e z arbitrary nuclear charge distribution with norm Coulomb interaction Point Charge Quadrupole moment Q T 2 = Q 2 - ME in aligned state m=j Look up/calculate
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W. Udo Schröder, 2005 Angular Momentum Coupling 28 Angular-Momentum Decomposition: Plane Waves Plane wave can be decomposed into spherical elementary waves z Spherical Bessel function
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W. Udo Schröder, 2005 Angular Momentum Coupling 29 j-Transfer Through Particle Emission/Absorption P T C N p+T
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W. Udo Schröder, 2005 Angular Momentum Coupling 30 Average Transition Probabilities f i If more than 1 initial state may be populated (e.g. diff. m) average over initial states Sum over all components of T k = total i f T k transition probability
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W. Udo Schröder, 2005 Angular Momentum Coupling 33 Translations x V(x) r V(r)
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