1.Description of correlations in mean-field and beyond mean-field methods

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1.Description of correlations in mean-field and beyond mean-field methods. Variational multiparticle-multihole configuration mixing method N.Pillet (1) , J.-F.Berger (1) , E.Caurier (2) , H.Goutte (1) , N.Vinh Mau (3) , F.Chappert (1). Spatial structure of Cooper pairs in HFB approach - PowerPoint PPT Presentation

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1.Description of correlations in mean-field and beyond mean-field

methods

Spatial structure of Cooper pairs in HFB approach

N.Pillet(1), N.Sandulescu(4), P.Schuck(3)

2.Nuclear excitations in plasmas

G.Gosselin(1), V.Méot(1), N.Pillet(1)

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Variational multiparticle-multihole configuration mixing method

N.Pillet(1), J.-F.Berger(1), E.Caurier(2), H.Goutte(1),

N.Vinh Mau(3), F.Chappert(1)

(1) SPN,CEA-Bruyères-le-Châtel (3) IPN, Orsay

(2) IPHC, Strasbourg (4) IPNE, Bucharest

Variational multiparticle-multihole configuration mixing

Motivations:

• Towards a unified description of correlations in the context of beyond mean- field method {essentially Pairing + RPA + particle-vibration coupling}

• Conservation of particle numbers + enforced Pauli principle

• Description on the same footing of even-even, odd and odd-odd nuclei

• Description of both ground states and excited states

Description of correlations in mean field and beyond mean field methods

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Formalism:

• Trial wave function: Superposition of Slater determinants corresponding to mpmh excitations built upon a given state of HF type

Description of correlations in mean field and beyond mean field methods

Variational multiparticle-multihole configuration mixing method

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

h2p2

h2p2

h1p1

h1p1h0p0 AAA

N

1ii 0a

m

1)kl(lkaawith an

d

+ + + …

• Variational principle

o Optimized single particle states:

o Mixing coefficients:

Description of correlations in mean field and beyond mean field methods

Variational multiparticle-multihole configuration mixing method

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

o Functional: )(H)(

0A

)(*

A)(H)(HA

0)(

*i

),(G),(h

Simultaneous solution of both equations (iterative):self-consistent procedure and renormalization of the

HF field

ˆwith

(*) N.Pillet, J-F.Berger and E.Caurier, under submission to PRC.

N.Pillet, N.Sandulescu, Nguyen Van Giai and J-F.Berger, Phys.Rev.C71, 044306 (2005).

Current study:

Description of correlations in mean field and beyond mean field methods

Variational multiparticle-multihole configuration mixing method

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Pairing correlations and link with projection on particle

number methods-Applications to Sn isotope ground states(*)

Structure of correlated wave functions

Correlation energy (MeV) Only configurations

with excited pairs

D1S Gogny force

ij 2

A)j,i(T

Description of correlations in mean field and beyond mean field methods

Variational multiparticle-multihole configuration mixing method

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Effect of correlations on single particle spectra

Charge radii

Future studies:

• Link with RPA – How to simulate RPA calculation with mp-mh method?

Which one-body density should be used?

• Description of light exotic nuclei (B, Li, Be, C, N, O, F) – PhD Proposal

Application of the mp-mh method to odd and odd-odd nuclei

Effect of general correlations on single particle spectra

Applications to island of inversionRe-fit of Gogny interaction (D2)?

Need for experimental data on masses, spins, parities… towards drip lines

Description of correlations in mean field and beyond mean field methods

Variational multiparticle-multihole configuration mixing method

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Spatial structure of Cooper pairs in HFB approach

(*) N. Pillet, N. Sandulescu and P. Schuck, Phys. Rev. C76, 024310 (2007).

• Method: HFB with D1S Gogny interaction

• Spherical nuclei: O, Ca, Ni, Sn, Pb isotopic chains

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Description of correlations in mean field and beyond mean field methods

Brody-Moshinsky transformation K(R,r) (R: center of mass, r: relative coordinates)

Two-body correlated wave function (J=0):

)(cosP)()r()r(K)1j2(41

)r,r(K 12ll

2l2n1l1nlj2n1n

lj1n2n0S21

0;lnln0;nlNl)(cosP)R2()2/r()l2

1l2()(

K)1j2(41

)r,R(K

1211lNlnNl

nl2/1

1

l

1j1l2n1n

1j1l

1n2n10S

2rr

R 21

21 rrr

and

Size of Cooper pairs:

2/122

2/124

dsindr,r,RKr

dsindr,r,RKr)R(

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Description of correlations in mean field and beyond mean field methods

Spatial structure of Cooper pairs in HFB approach

Strong coupling behavior of Cooper pairs on the surface of superfluid nuclei

Probability Distribution

222 )r,R(KRr)r,R(P

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Description of correlations in mean field and beyond mean field methods

Spatial structure of Cooper pairs in HFB approach

Future study: Generalization to deformed nuclei where the parity mixing is expected to be stronger + nucleon pair transfer

Nuclear excitations in plasmas

Photon absorption

NEEC

(nuclear excitation by electron capture)

NEET

(nuclear excitation by electronic transition)

Inelastic electron scattering

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Main excitation processes

Corresponding de-excitation processes Photon emission

spontaneous+ stimulated

IC

(internal conversion)

BIC

(bound internal conversion)

(*) P.Morel, V.Méot, G.Gosselin, D.Gogny and W.Younes, Phys.Rev.A69, 063414 (2004).

(*) G. Gosselin, V. Méot and P. Morel, Phys.Rev.C76, 044611 (2007).(*) G. Gosselin, V. Méot and P. Morel, Phys.Rev.C70, 064603 (2004).

•Photon absorption, NEET and NEEC mechanisms (*):

First order perturbation theory Fermi golden rule

Method for transition rate calculation:

•Inelastic electron scattering: (under development)

Second order perturbation theory

PWBA, WKB, DWBA (radial transition matrix element)

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Nuclear excitations in plasmas

201Hgm

Two level model

Photon+NEEC/IC+NEET/BIC

(thermodynamical equilibrium)

(*) V.Méot, J.Aupiais, P.Morel, G.Gosselin, F.Gobet, J.N.Scheurer and M.Tarisien, Phys. Rev. C75, 064306 (2007).

201Hg

g.s.0 keV

1.56 keV

26.27 keV

81ns(*)3/2-

1/2-

5/2- 630ps

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Nuclear excitations in plasmas

Lifetime of first 201Hgm

Future: inclusion of inelastic electron scattering

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Future

• Variational multiparticle-multihole configuration mixing method

• Spatial structure of Cooper pairs

• Nuclear excitations in plasmas

Link with RPA

Study of light nuclei- PhD proposal

Test and possible re-fit of Gogny interaction (D2)

Generalization to deformed nuclei + pair transfer

Inclusion of inelastic electron scattering

Κ2(R,r) in Sn isotopes and Parity mixing effect

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Description of correlations in mean field and beyond mean field methods

Spatial structure of Cooper pairs in HFB approach

Shell effects + Parity mixing effects

Probability Distribution 222 )r,R(KRr)r,R(P

nathalie.pillet@cea.fr

Jeunots 2008, February 4-6 (2008), Saclay

Description of correlations in mean field and beyond mean field methods

Spatial structure of Cooper pairs in HFB approach

dr)r,R(Kr

)r,R(Kr)r,R(W 22

22

Future study: Generalization to deformed nuclei where the parity mixing is expected to be stronger + nucleon pair transfer

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