PAIRING PROPERTIES OF SUPERHEAVY NUCLEI A. Staszczak, J. Dobaczewski and W. Nazarewicz

20
9/28/2006 19:01 (00) PAIRING PROPERTIES PAIRING PROPERTIES OF SUPERHEAVY NUCLEI OF SUPERHEAVY NUCLEI A. Staszczak, J. Dobaczewski and W. Nazarewicz A. Staszczak, J. Dobaczewski and W. Nazarewicz (KFT UMCS) (IFT UW) (ORNL & UT) (KFT UMCS) (IFT UW) (ORNL & UT)

description

PAIRING PROPERTIES OF SUPERHEAVY NUCLEI A. Staszczak, J. Dobaczewski and W. Nazarewicz (KFT UMCS) (IFT UW) (ORNL & UT). The constrained HF procedure The constraints act as the external fields capable to deform the nucleus in different ways - PowerPoint PPT Presentation

Transcript of PAIRING PROPERTIES OF SUPERHEAVY NUCLEI A. Staszczak, J. Dobaczewski and W. Nazarewicz

Page 1: PAIRING  PROPERTIES OF  SUPERHEAVY  NUCLEI A. Staszczak, J. Dobaczewski and W. Nazarewicz

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PAIRING PROPERTIESPAIRING PROPERTIESOF SUPERHEAVY NUCLEIOF SUPERHEAVY NUCLEI

A. Staszczak, J. Dobaczewski and W. NazarewiczA. Staszczak, J. Dobaczewski and W. Nazarewicz

(KFT UMCS) (IFT UW) (ORNL & UT)(KFT UMCS) (IFT UW) (ORNL & UT)

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The constrained HF procedure

The constraints act as the external fields capable to deform the nucleus in different ways

The collective coordinates can be defined in a natural way by measuring the deformations generated by the various constraints

The constrained mean field theory defines the deformed states(BCS- or HFB-type) that solve the variational equation:

with the constraint conditions

ˆˆ ˆ{ } { } , { } { } , { } { } .j jq N q N q Z q Z q Q q q

{ }q

212

ˆˆ ˆ ˆ{ } { } 0N Z j j jjq H N Z c Q q

quadratic multipole constraints

The multipole constraints prescribe different kinds of deformation characterized by the set of parameters

1 2{ } { , ,..., }.Nq q q q

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is the many-body nuclear (non-relativistic) Hamiltonian H

2

2( )

1

ˆˆ 1ˆ ˆ2 2 2

A Aii effiij

i i j

ppH V

m Am

center-of-mass “projection” term(in the VAP technique),

to eliminate spurious mode associated with the broken translational symmetry

nuclear effective interaction term(Skyrme, Gogne type forces)

To describe the fission process most “important” are the low-multipolarity mass moments, i.e.,

2 *20 20

3 *30 30

4 *40 40

ˆ ( ) 16 5 ( , ),

ˆ ( ) 4 7 ( , ),

ˆ ( ) 4 9 ( , ).

i i ii

i i ii

i i ii

Q r r Y

Q r r Y

Q r r Y

“nuclear stretching”

“reflection-asymmetry”

“necking”

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-50 0 50 100 150 200 250 300 350

-1804

-1802

-1800

-1798

-1796

-1794

-1792

-1790

-1788

-1786

-1784

EIII

Tot

al E

nerg

y [M

eV]

Q20

[b]

680 (14) 816 (15) 969 (16) 1000 1140(17) 1330(18) 1540(19) 1771(20)

reflection-symmetric path 240Pu

EA E

IIE

B

Size of the basis

1140 s. p. states of deformed 3D h. o.

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Seniority pairing:Seniority pairing:J. Dudek, et al., J. Phys. G6 (1980)447.

/ /

/

18.95 0.078 , 88 17.90 0.176 , 88

19.3 0.084 , 88 13.3 0.217 , 88

n p

n p

n p

n p

N Z N ZZ Z

A AG G

N Z N ZZ Z

A A

fG G

1 2

-31 2 0

0

12

/0

/1 2

2 , 0.16 fm , 1,

0, delta interaction (DI)

1, density-depende

" "

" "

"

nt delta interaction (DDDI)

, (MIX)

, 1n p n p

volume pair

r r

r r

ing

surface pairing

mixe

V r r V

"d pairing

Zero-range pairing force:Zero-range pairing force:R. R. Chasman, Phys. Rev. C 14 (1976)1935.G. F. Bertsch and H. Esbensen, Ann. Phys. (N.Y.) 209 (1991)327.

/n pf/

0n pV

In the paring (BCS) window n/pN (or Z) s. p. states are taken, and parameters are chosen to reproduce n/p for 252Fm.

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The spectral (average) gap:

/

/

// , : or s.p. states

n p

n p

k k k n pkn p

k kk

v uN Z

v u

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SLy4

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SLy4

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SLy4

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-50 0 50 100 150 200 250 300-2056

-2052

-2048

-2044

-2040

-2036

-2032

Etot Q40

MIX DDDI DI G

Quadrupole Moment Q20

[b]

Tot

al E

nerg

y E

tot [M

eV] 288Rf

184

0

10

20

30

40

50

60

70

80

90

Hexadecapole M

oment Q

40 [b2] -50 0 50 100 150 200 250 300

-2080

-2070

-2060

-2050

-2040

-2030

Quadrupole Moment Q20

[b]

288Rf184T

ota

l En

erg

y E

tot [M

eV

]

0.0

0.5

1.0

1.5

2.0

Pa

iring

Ga

p

n/p [Me

V]

-50 0 50 100 150 200 250 300-2116

-2112

-2108

-2104

-2100

-2096

-2092

Etot Q40

MIX DDDI DI G

298114184

Quadrupole Moment Q20

[b]

Tot

al E

nerg

y E

tot [M

eV]

0

10

20

30

40

50

60

70

80

90 Hexadecapole M

oment Q

40 [b2]

-50 0 50 100 150 200 250 300-2140

-2130

-2120

-2110

-2100

-2090

298114184

Quadrupole Moment Q20

[b]

Tot

al E

nerg

y E

tot [M

eV]

0.0

0.5

1.0

1.5

2.0

Pairing G

ap n/p [M

eV]

-50 0 50 100 150 200 250 300

-2140

-2136

-2132

-2128

-2124

-2120 310126184

Etot Q40

MIX DDDI DI G

Quadrupole Moment Q20

[b]

Tot

al E

nerg

y E

tot [M

eV]

0

10

20

30

40

50

60

70

80

90

Hexadecapole M

oment Q

40 [b2] -50 0 50 100 150 200 250 300

-2160

-2150

-2140

-2130

-2120 310126184

Quadrupole Moment Q20

[b]

Tot

al E

nerg

y E

tot [M

eV]

0.0

0.5

1.0

1.5

2.0

Pairing G

ap n/p [M

eV]

SLy4

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Quadrupole Moment Q20 [b]

Total Energy Etot [MeV]

Hexadecapole M

oment Q

40 [b2]

-50 0 50 100 150 200 250 300

-2068

-2064

-2060

-2056

-2052

-2048 290Sg184

MIX0102030405060708090

-50 0 50 100 150 200 250 300-2056

-2052

-2048

-2044

-2040

-2036

-2032288Rf

184

MIX0102030405060708090

-50 0 50 100 150 200 250 300

-2084

-2080

-2076

-2072

-2068

-2064 292Hs184

MIX

0102030405060708090

-50 0 50 100 150 200 250 300

-2096

-2092

-2088

-2084

-2080

-2076 294Ds184

MIX

0102030405060708090

-50 0 50 100 150 200 250 300-2108

-2104

-2100

-2096

-2092

-2088

-2084296112

184

MIX

0102030405060708090

-50 0 50 100 150 200 250 300-2116

-2112

-2108

-2104

-2100

-2096

-2092

298114184

0102030405060708090

MIX

-50 0 50 100 150 200 250 300-2124

-2120

-2116

-2112

-2108

-2104

-2100300116

184

MIX

0102030405060708090

-50 0 50 100 150 200 250 300

-2128

-2124

-2120

-2116

-2112

-2108 302118184

MIX

0102030405060708090

-50 0 50 100 150 200 250 300

-2132

-2128

-2124

-2120

-2116

-2112 304120184

MIX

0102030405060708090

-50 0 50 100 150 200 250 300-2136

-2132

-2128

-2124

-2120

-2116

-2112306122

184

MIX0102030405060708090

-50 0 50 100 150 200 250 300

-2136

-2132

-2128

-2124

-2120

-2116 308124184

MIX

0102030405060708090

-50 0 50 100 150 200 250 300

-2136

-2132

-2128

-2124

-2120

-2116 310126184

MIX

0102030405060708090

Etot

Q40

Etot

Q40

MIX

SLy4

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Etot

n

p

Etot

n

pQuadrupole Moment Q20 [b]

Total Energy Etot [MeV]

Pairing G

ap n/p [M

eV]

-50 0 50 100 150 200 250 300-2160

-2150

-2140

-2130

-2120

-2110

310126184

MIX0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2160

-2150

-2140

-2130

-2120

-2110

308124184

0.0

0.5

1.0

1.5

2.0

MIX

-50 0 50 100 150 200 250 300-2160

-2150

-2140

-2130

-2120

-2110

306122184

0.0

0.5

1.0

1.5

2.0

MIX

-50 0 50 100 150 200 250 300-2150

-2140

-2130

-2120

-2110

-2100

302118184

MIX0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2150

-2140

-2130

-2120

-2110

-2100

0.0

0.5

1.0

1.5

2.0

MIX

300116184

-50 0 50 100 150 200 250 300-2140

-2130

-2120

-2110

-2100

-2090

MIX

298114184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2130

-2120

-2110

-2100

-2090

-2080

296112184

MIX

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2120

-2110

-2100

-2090

-2080

-2070

294Ds184

MIX

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2110

-2100

-2090

-2080

-2070

-2060

292Hs184

MIX

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2090

-2080

-2070

-2060

-2050

-2040

290Sg184

MIX

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2080

-2070

-2060

-2050

-2040

-2030288Rf

184

MIX

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2160

-2150

-2140

-2130

-2120

-2110

304120184

MIX

0.0

0.5

1.0

1.5

2.0

MIX

SLy4

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SummarySummary

We compared “volume”, “surface” and “mixed” zero-range nuclear pairing forces with monopole pairing.

Applying “mixed” -interaction we have investigated total binding energies (barriers) and spectral pairing gaps along fission paths of even-even superheavy nuclei with N = 184.

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KONIEC

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P. Möller, J. R. Nix, and K.-L. Kratz Atomic Data’97

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Quadrupole Moment Q20 [b]

Total Energy Etot [MeV]

Hexadecapole M

oment Q

40 [b2]

-50 0 50 100 150 200 250 300-2056

-2052

-2048

-2044

-2040

-2036

-2032288Rf

184

Etot

Q40

0102030405060708090

-50 0 50 100 150 200 250 300-2072

-2068

-2064

-2060

-2056

-2052

-2048290Sg

184

Etot

Q40

0102030405060708090

-50 0 50 100 150 200 250 300

-2084

-2080

-2076

-2072

-2068

-2064

Etot

Q40

292Hs184

0102030405060708090

-50 0 50 100 150 200 250 300

-2096

-2092

-2088

-2084

-2080

-2076

Etot

Q40

294Ds184

0102030405060708090

-50 0 50 100 150 200 250 300-2116

-2112

-2108

-2104

-2100

-2096

-2092

298114184

Etot

Q40

0102030405060708090

-50 0 50 100 150 200 250 300

-2136

-2132

-2128

-2124

-2120

-2116

Etot

Q40

0102030405060708090

306122184

-50 0 50 100 150 200 250 300-2108

-2104

-2100

-2096

-2092

-2088

-2084

Etot Q

40

296112184

0102030405060708090

-50 0 50 100 150 200 250 300

-2132

-2128

-2124

-2120

-2116

-2112 304120184

Etot

Q40

0102030405060708090

-50 0 50 100 150 200 250 300-2140

-2136

-2132

-2128

-2124

-2120

-2116

Etot

Q40

0102030405060708090

308124184

-50 0 50 100 150 200 250 300-2124

-2120

-2116

-2112

-2108

-2104

-2100

300116184

Etot

Q40

0102030405060708090

-50 0 50 100 150 200 250 300-2140

-2136

-2132

-2128

-2124

-2120

-2116310126

184

Etot

Q40

0102030405060708090

-50 0 50 100 150 200 250 300

-2128

-2124

-2120

-2116

-2112

-2108 302118184

Etot

Q40

0102030405060708090

G

SLy4

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Quadrupole Moment Q20 [b]

Total Energy Etot [MeV]

Pairing G

ap [MeV

]

-50 0 50 100 150 200 250 300

-2150

-2140

-2130

-2120

-2110 302118184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300

-2160

-2150

-2140

-2130

-2120

310126184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300

-2120

-2110

-2100

-2090

-2080

294Ds184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2110

-2100

-2090

-2080

-2070

-2060

292Hs184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2150

-2140

-2130

-2120

-2110

-2100300116

184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300

-2160

-2150

-2140

-2130

-2120

308124184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300

-2160

-2150

-2140

-2130

-2120

306122184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2160

-2150

-2140

-2130

-2120

-2110304120

184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300

-2130

-2120

-2110

-2100

-2090 296112184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2140

-2130

-2120

-2110

-2100

-2090298114

184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300

-2090

-2080

-2070

-2060

-2050

290Sg184

0.0

0.5

1.0

1.5

2.0

-50 0 50 100 150 200 250 300-2080

-2070

-2060

-2050

-2040

-2030

288Rf184

0.0

0.5

1.0

1.5

2.0

Etot

n

p

Etot

n

p

G

SLy4

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