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tens of MeV + NNN +.... ab initio Intro: define fundaments my model is „standing on” sp mean-field ( or nuclear DFT ) beyond mean-field ( projection after variation ) Summary Symmetry (isospin) violation and restoration: unphysical symmetry violation isospin projection Coulomb rediagonalization (explicit symmetry violation) in collaboration with J. Dobaczewski, W. Nazarewicz & M. Rafalski structural effects SD bands in 56 Ni ISB corrections to superallowed beta decay isospin impurities in ground-states of e-e nuclei Results
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Skyrme-force-inspired local energy density functional (without pairing) LS | v(1,2) | average Skyrme interaction (in fact a functional!) over the Slater determinant local energy density functional Deformation (q) Total energy (a.u.) Symmetry-conserving configurtion Symmetry-breaking configurations SV is the only Skyrme interaction Beiner et al. NPA238, 29 (1975)
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Euler angles in space or/and isospace gauge angle rotated Slater determinants are equivalent solutions where Beyond mean-field multi-reference density functional theory
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Find self-consistent HF solution (including Coulomb) deformed Slater determinant |HF>: in order to create good isospin „basis”: Apply the isospin projector: Engelbrecht & Lemmer, PRL24, (1970) 607 Diagonalize total Hamiltonian in „good isospin basis” | ,T,T z > takes physical isospin mixing C = 1 - |a T=T z | 2 AR n=1 C = 1 - |b T=|T z | | 2 BR See: Caurier, Poves & Zucker, PL 96B, (1980) 11; 15
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(I)Isospin impurities in ground states of e-e nuclei Here the HF is solved without Coulomb |HF;e MF =0>. Here the HF is solved with Coulomb |HF;e MF =e>. In both cases rediagonalization is performed for the total Hamiltonian including Coulomb W.Satuła, J.Dobaczewski, W.Nazarewicz, M.Rafalski, PRL103 (2009) 012502
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0 1 2 3 4 5 6 0 0.2 0.4 0.6 0.8 1.0 20283644526068768492 A AR BR SLy4 C [%] E-E HF [MeV] N=Z nuclei 100 This is not a single Slater determinat There are no constraints on mixing coefficients (II) Isospin mixing & energy in the ground states of e-e N=Z nuclei: ~30% C HF tries to reduce the isospin mixing by: in order to minimize the total energy Projection increases the ground state energy ( the Coulomb and symmetry energies are repulsive) Rediagonalization (GCM) lowers the ground state energy but only slightly below the HF
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Excitation energy of the T=1 doorway state in N=Z nuclei 20 25 30 35 20406080100 A SIII SLy4 SkP E(T=1)-E HF [MeV] mean values Sliv & Khartionov PL16 (1965) 176 based on perturbation theory E ~ 2h ~ 82/A 1/3 MeV Bohr, Damgard & Mottelson hydrodynamical estimate E ~ 169/A 1/3 MeV 31.532.032.533.033.534.034.5 y = 24.193 – 0.54926x R= 0.91273 doorway state energy [MeV] 4 5 6 7 C [%] 100 Sn SkO SIII MSk1 SkP SLy5 SLy4 SkO’ SLy SkP SkM* SkXc l=0, n r =1 N=2
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aligned configuration anti-aligned configuration or or T=0 Isospin projection T=1 T=0 Mean-field four-fold degeneracy of the sp levels Spontaneous isospin mixing in N=Z nuclei in other but isoscalar configs yet another strong motivation for isospin projection
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D. Rudolph et al. PRL82, 3763 (1999) f 7/2 f 5/2 p 3/2 neutrons protons 4p-4h [303]7/2 [321]1/2 Nilsson 1 space-spin symmetric 2 f 7/2 f 5/2 p 3/2 neutrons protons g 9/2 p-h two isospin asymmetric degenerate solutions Isospin symmetry violation in superdeformed bands in 56 Ni
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4 8 12 16 20 51015 51015 Exp. band 1 Exp. band 2 Th. band 1 Th. band 2 Angular momentum Excitation energy [MeV] Hartree-Fock Isospin-projection C [%] band 1 2 4 6 8 band 2 56 Ni ph ph T=0 T=1 centroid W.Satuła, J.Dobaczewski, W.Nazarewicz, M.Rafalski, PRC81 (2010) 054310
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SVD SVD eigenvalues (diagonal matrix ) Isospin-projection is non-singular: singularity (if any) at is inherited by 1 + |N-Z| - + |N-Z|+2k k is a multiplicity of zero singular values > 3 in the worst case W.Satuła, J.Dobaczewski, W.Nazarewicz, M.Rafalski, PRC81 (2010) 054310 ij = i * O ij j ~
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0 10 20 30 40 1357 C [%] 2K isospin isospin & angular momentum 0.586(2)% 42 Sc – isospin projection from [K,-K] configurations with K=1/2,…,7/2 Isospin and angular-momentum projected DFT is ill-defined except for the hamiltonian-driven functionals
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0.0001 0.001 0.01 0.1 1 0.00.51.01.52.02.53.0 |OVERLAP| T [rad] only IP IP+AMP inverse of the overlap matrix space & isospin rotated sp state HF sp state T ij = i * O ij j
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s 1/2 p 3/2 p 1/2 p 2 8 np 2 8 n d 5/2 Hartree-Fock f statistical rate function f (Z,Q ) t partial half-life f (t 1/2,BR) G V vector (Fermi) coupling constant Fermi (vector) matrix element | | 2 =2(1- C ) T z =-/+1 J=0 +,T=1 +/- (N-Z=-/+2) (N-Z=0) T z =0 10 cases measured with accuracy ft ~0.1% 3 cases measured with accuracy ft ~0.3%
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~2.4% Marciano & Sirlin, PRL96, 032002, (2006) nucleus-independent ~1.5% 0.3% - 2.0% e NS-independent The 13 precisely known transitions, after including theoretical corrections, are used to NS-dependent Towner & Hardy Phys. Rev. C77, 025501 (2008) Towner, NPA540, 478 (1992) PLB333, 13 (1994) e courtesy of J.Hardy
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one can determine mass eigenstates CKM Cabibbo-Kobayashi-Maskawa weak eigenstates With the CVC being verified and knowing G (muon decay) test unitarity of the CKM matrix 0.9491(4) 0.0504(6) <0.0001 |V ud | 2 +|V us | 2 +|V ub | 2 =0.9996(7) |V ud | = 0.97425 + 0.00023 test of three generation quark Standard Model of electroweak interactions
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Towner & Hardy Phys. Rev. C77, 025501 (2008) Liang & Giai & Meng Phys. Rev. C79, 064316 (2009) spherical RPA Coulomb exchange treated in the Slater approxiamtion C = C2 + C1 shell model mean field Miller & Schwenk Phys. Rev. C78 (2008) 035501;C80 (2009) 064319 radial mismatch of the wave functions configuration mixing
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Isobaric symmetry violation in o-o N=Z nuclei ground state is beyond mean-field! T=0 T=0 T=1 Mean-field can differentiate between and only through time-odd polarizations! aligned configurations anti-aligned configurations or or CORE T z =-/+1 J=0 +,T=1 +/- (N-Z=-/+2) (N-Z=0) T z =0
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ground state in N-Z=+/-2 (e-e) nucleus antialigned state in N=Z (o-o) nucleus Project on good isospin (T=1) and angular momentum (I=0) ( and perform Coulomb rediagonalization) <T~1,T z =+/-1,I=0| |I=0,T~1,T z =0> +/- H&T C =0.330% L&G&M C =0.181% ~ ~ Project on good isospin (T=1) and angular momentum (I=0) ( and perform Coulomb rediagonalization)
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V ud =0.97418(26) V ud =0.97447(23) Ft=3071.4(8)+0.85(85) Ft=3070.4(9) |V ud | 2 +|V us | 2 +|V ub | 2 = =1.00031(61) W.Satuła, J.Dobaczewski, W.Nazarewicz, M.Rafalski, PRL106 (2011) 132502
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0.970 0.971 0.972 0.973 0.974 0.975 0.976 |V ud | superallowed -decay + -decay -decay T=1/2 mirror -transitions H&T’08 Liang et al.
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0 0.5 1.0 1.5 2.0 01020304050607080 2.5 T z T z +1 T z = -1 T z = 0 C [%] A N cutoff =10 N cutoff =12 A=18 A=38 A=58
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[Isospin projection, unlike the angular-momentum and particle-number projections, is practically non-singular !!!] Elementary excitations in binary systems may differ from simple particle-hole (quasi-particle) exciatations especially when interaction among particles posseses additional symmetry ( like the isospin symmetry in nuclei ) Superallowed 0 + 0 + beta decay: encomaps extremely rich physics: CVC, V ud, unitarity of the CKM matrix, scalar currents… connecting nuclear and particle physics … there is still something to do in c business … Projection techniques seem to be necessary to account for those excitations - how to construct non-singular EDFs? Pairing & other (shape vibrations) correlations can be „realtively easily” incorporated into the scheme by combining projection(s) with GCM
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0 2 4 6 1020304050 a’ sym [MeV] SV SLy4 L SkM L * SLy4 A (N=Z) T=0 T=1 E’ sym = a’ sym T(T+1) 1 2 a’ sym a sym =32.0MeV a sym =32.8MeV SLy4: In infinite nuclear matter we have: SV: a sym =30.0MeV SkM*: a sym = e F + a int m m* SLy4: 14.4MeV SV: 1.4MeV SkM*: 14.4MeV
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