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Isovector scenario for nuclei near the N=Z line

Isovector scenario for nuclei near the N=Z line. Anatoli Afanasjev S. Frauendorf Kai Neergard J. Sheikh. Mean-field theory of isovector pairing. Mean-field calculations in the A=74 region. Isocranking and RPA. Mean-field theory of isovector pairing. S. F., J Sheikh, NPA 645 (1999) 509.

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Isovector scenario for nuclei near the N=Z line

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  1. Isovector scenario for nuclei near the N=Z line Anatoli Afanasjev S. Frauendorf Kai Neergard J. Sheikh

  2. Mean-field theory of isovector pairing Mean-field calculations in the A=74 region Isocranking and RPA

  3. Mean-field theory of isovector pairing S. F., J Sheikh, NPA 645 (1999) 509

  4. Simple model: deformed potential+monopole isovector pairing

  5. Mean-field approximation

  6. Spontaneous breaking of isospin symmetry Mean field does not have these symmetries. Degenerate mf-solutions: gauge angle

  7. Symmetry restoration –Isorotations (strong symmetry breaking) Bayman, Bes, Broglia PRL 23 (1969) 1299 ( 2 particle transfer)

  8. The relative strengths of pp, nn, and pn pairing are determined by the isospin symmetry Moment of inertia for isorotation

  9. 10 20 30 40 50 60 A Ground states

  10. Parities of proton and neutron numbers are good. Intrinsic excitation spectrum Symmetries

  11. T=0 and ½ states

  12. States with good N, Z –parity are in general no eigenstates of If they are (T=0) the symmetry restricts the possible configurations, if not (T=1/2) the symmetry does not lead to anything new. Restrictions due to the

  13. Model study: half-filled deformed j-shell Full shell model diagonalization HFB solution: no isoscalar pair field, only isovector

  14. Quasiparticle routhians Mean-field kept at its value at

  15. Mean-field calculations in the A=74 region D. Jenkins, et al. PRC 65 (2002) 064307 N. S. Kelsall et al. Proc. Berkeley 2002, AIP Conf. Proc. 656 (2002) 269 N. S. Kelsall et al. PRC65 (2002) 044331 C.D. O’Leary et al. PRC 67 (2003) 021301(R)

  16. Realistic calculations Cranked Relativistic Mean-Field Pairing: Gogny force, HFB, Lipkin-Nogami Isocranking: experimental symmetry energy

  17. Quasiparticles around N=Z=36

  18. Calculation TRS, R. Wyss

  19. full: experiment dashed: CRMF

  20. full: experiment dashed: CRMF

  21. no pairing

  22. Isocranking and RPA

  23. Too small symmetry energy With realistic level spacing h Ensures the right symmetry Energy by choice of k Symmetry restoration by RPA Kai Neergard, PLB 537 (2002) 287, ArXiv nucl-th Mean-field approximation

  24. T T+1/2 RPA correlation energy RPA roots 2qp energies

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