strong tensor correlation in light nuclei with tensor-optimized antisymmetrized molecular dynamics...
DESCRIPTION
3 Pion exchange interaction & V tensor interaction Yukawa interaction involve large momentum Tensor operator -V tensor produces the high momentum component.TRANSCRIPT
Strong tensor correlation in light nucleiwith tensor-optimized antisymmetrized
molecular dynamics (TOAMD)
International symposium on “High-resolution Spectroscopy and Tensor interactions” (HST15), Osaka, 2015.11
Takayuki MYO
2
Outline
• Tensor Optimized Shell Model (TOSM)• Importance of 2p2h excitation involving high-
momentum component for tensor correlation
• Applications to He, Li, Be isotopes
• Tensor Optimized AMD (TOAMD)• Toward clustering with tensor correlation
• Formulation given in PTEP 2015, 073D02
3
Pion exchange interaction & Vtensor
d interaction
Yukawa interaction
involve largemomentum
2 2 2
1 2 1 2 122 2 2 2 2 2
2 2 2 2
1 2 122 2 2 2 2 2
ˆ ˆ3( )( ) ( )
( )
q q qq q Sm q m q m q
m q m qSm q m q m q
12 1 2 1 2ˆ ˆ3( )( ) ( )S q q
Tensor operator
- Vtensor produces the high momentum component.
S
D
Energy -2.24 MeV
Kinetic 19.88
Central -4.46
Tensor -16.64
LS -1.02
P(L=2) 5.77%
Radius 1.96 fmVcentral
Vtensor
AV8’
Deuteron properties & tensor force
Rm(s)=2.00 fm
Rm(d)=1.22 fm d-wave is “spatially compact” (high momentum)
r
0,k
H EC
1
,A A
i G iji i j
H t T v
( ) ( )k kk
A C A
,0
lj n
H Eb
c.m. excitation is excluded by Lawson’s method
(0p0h+1p1h+2p2h)
1
' ', ,( ) ( )
N
n
n nlj lj n lj nC
r r
,1/2
2
,1 ˆ( ) exp ( ),2 lj n
llj n l j
rr Yb
r r
particle state Gaussian expansion for each orbit
Gaussian basis function' ''', ''
n nlj lj n n d
Hiyama, Kino, Kamimura PPNP51(2003)223
Shell model type configuration with mass number A
Tensor-optimized shell model (TOSM)TM, Sugimoto, Kato, Toki,
IkedaPTP117(2007)257
particle
hole
6
Tensor force matrix elements
6• Centrifugal potential ([email protected]) pushes away D-wave.
p+r (Bonn) AV8’
VT = Vresidual
VT ≠ Vresidual
MSD(r) = r2·S(r,bS)·VT·D(r,bD)
Integrand of Tensor MEbD ~ bS
bD ~ bS0.5
1st order
0p0h-2p2h
3.8 MeV15.0 MeV
high momentum
He, Li, Be isotopes in TOSM
7
TM, A. Umeya, H. Toki, K. Ikeda PRC84 (2011) 034315TM, A. Umeya, H. Toki, K. Ikeda PRC86 (2012) 024318TM, A. Umeya, K. Horii, H. Toki, K. Ikeda PTEP (2014) 033D01TM, A. Umeya, H. Toki, K. Ikeda PTEP (2015) 073D02
T
VT
VLS
VC
E
(exact)Kamada et al.PRC64 (Jacobi)
• Gaussian expansion at most with 9 bases
• variational calculation
TM, H. Toki, K. IkedaPTP121(2009)511
4He in TOSM + central UCOM
good convergence
• High-k components bring large kinetic energy
Selectivity of the tensor coupling in 4He
9
DL = 2 DS = 2Selectivity of S12
s1 s2 s3 s41+(pn) 1+(pn)
s1 s2 s3 s4 L=2
s1 s2 s3 s4 L=2
VT
VT2𝑝2 h :(0 𝑠)10
2 [ (1𝑠 ) (𝑑3/2 ) ]10
2𝑝2 h :(0 𝑠)102 (𝑝1/2)10
2
0𝑝 0 h : (0 𝑠 )4
l1=l2=l3=l4=0l1=l2=0
l1=l2=0
l3=1l4=1
l3=0l4=2
5-8He with TOSM+UCOM• Excitation energies in MeV
• Excitation energy spectra are reproduced well
TM, A. Umeya, H. Toki, K. Ikeda PRC84 (2011) 034315
5-9Li with TOSM+UCOM• Excitation energies in MeV
• Excitation energy spectra are reproduced well
TM, A. Umeya, H. Toki, K. Ikeda PRC86(2012) 024318
1212
Radius of He & Li isotopes
I. Tanihata et al., PLB289(‘92)261 G. D. Alkhazov et al., PRL78(‘97)2313O. A. Kiselev et al., EPJA 25, Suppl. 1(‘05)215. P. Mueller et al., PRL99(2007)252501
Expt
Halo SkinA. Dobrovolsky, NPA 766(2006)1
TOSM with AV8’
8Be spectrum
13a-a structure
• Argonne Group– Green’s function Monte Carlo
C. Pieper, R. B. Wiringa, Annu.Rev.Nucl.Part.Sci.51 (2001)
TUNL
G~ few MeV
G< 1MeV
8Be in TOSM AV8’
• VT 1.1, VLS 1.4– simulate 4He benchmark
(Kamada et al., PRC64) • correct level order (T=0,1)• tensor contribution : T=0 > T=1• a : 0p0h+2p2h with high-k
– 2a needs 4p4h.– spatial asymptotic form of 2a
14
a aclustering
TOSM
Expt. (TUNL)
TOAMD
Tensor-Optimized Antisymmetrized Molecular Dynamics (TOAMD)
15
TM, H. Toki, K. Ikeda, H. Horiuchi, T. Suhara, PTEP 2015, 073D02
Toward the clustering with tensor correlation explicitly
(TOAMD)
AMD AMD
2 212
0,1
2
,
TOAMD AMD
( ) , ( ) exp( )
( ) , ( ) exp( )
D S
At
D D i j D n nt i j n
Ast
S S i j S n ns t i j n
F F
F f r r f r C a r r S
F f r r f r C a r
tensor correlation
short-range correlation
2p2h0p0h Gaussian expansion
Formulation of TOAMD
17
0 AMD AMD
AMD AMD AMD
2 212
0,1
TOAMD AMD
( ) , ( ) exp( )
D SD S
SD DD SSS D D D S S
At
D D i j D n nt i j n
GN
C F F
F F F F F F
F f r r f r r S C a r
2p2h
4p4h
0p0h
• Variational parameters– n, Zi (i=1,…, A) , spin-direction (up/down) in AMD
– C0 , Cn , an , NG in Gaussian expansion
– Solve cooling equation for
Matrix elements of multi-body operator
• generates at most 6-body matrix elements.
• Classify the connections between the operators.
' ' Aˆ... ...i j i jO
1
2
AMD1 det ,...,
!
exp
AA
n
Z
r Z r ZT T
ˆ , , , , ,
D D S S S D
D D S S
O F F F F F FF V F F V F
VT
FD
FD
2-body
VT
FD
FD
4-body
Matrix elements
particlecoordinate
centroid
range
Matrix elements with Fourier trans.• Fourier transformation of the interaction V & FD, FS.
– Y. Goto and H. Horiuchi, Prog. Theor. Phys., 62 (1979) 662– Gaussian expansion of V, FD, FS for relative motion– Multi-body operators are represented in the separable form
for particle coordinates.– Three-body interaction can be treated in the same manner.
19
3/2
3
3/2 22 2
12 123
2
2 2
2 2
( ) /4
( ) /4
1 (2 )
1( ) ( )(2 ) 2
exp / 8 ( ) / 2
ij
ikr
i j i
i j
j
ji
a r r k a
a r r k a
ikrikr
ikrikr
e dk e e ea
ir S r e dk e e e k S ka a
e k ik
pp
pp
n
Z Z Z Z Z Z
relativesingle particle
tensor-type
overlap Quadratic + Linear terms of k
Matrix elements with Fourier trans.
• Example : FDVT
AMD T 2 AMD 1 2
ijk, i'j'k'
1 1 2 2 ' ' ' ' ' ' ' '' '' '
1 1' ' ' ' ' '
2 21 1 2 2
1 2 1 2
/4 /4( )
3δ δ δ δ 3δ δ δ δ
det
D
i i j j
x y u v xx yy xy x y uu vv uv u vxyx yuvu v
i x u i j y v j i i j j
k a k a
ik r ik r ik r ik r
F V dk dk e e
e e e e
k k k k
B B
Ζ Z Z Z
VT
FD
2-body (2-body)(2-body) = (2-body)+(3-body)+(4-body)
k-integral
spatial part
(tensor)2
spin-isospin part antisymmetrization
𝑘2
𝑘1 a1
a2
Bij=ij
overlap
Matrix elements with Fourier trans.
• Example : FDVT
21
AMD T 3 AMD 1 2
ijk, i'j'k'
1 1 2 2 ' ' ' ' ' ' ' '' '' '
' ' ' ' '
2 21 1 2 2
1 1 2 2
/4 /4( )
3δ δ δ δ 3δ δ δ δ
det
D
i i j j k k
x y u v xx yy xy x y uu vv uv u vxyx yuvu v
i x i j y u j k v k i i
k a k a
ik r ik r ik r ik r
F V dk dk e e
e e e e
k k k k
B
Ζ Z Z Z Z Z
1 1 1' 'j j k kB B
VT
FD
3-body (2-body)(2-body) = (2-body)+(3-body)+(4-body)
k-integral
spatial part
(tensor)2
spin-isospin part antisymmetrization
𝑘2
𝑘1 a1
a2
Bij=ij
overlap
TOSM vs. TOAMD
22
TOSM TOAMD
Correlation 1p1h, 2p2h(single particle)
Relative motion in FD, FS
CM excitation Lawson method Nothing with single n
Hole states harmonic oscillator basis
Can optimize in each basis
Short-range repulsion central-UCOM
Correlation function, FS
Results
• 3H, 4He, 8Be (preliminary)• AV8’ (central+LS+tensor) • |TOAMD= |AMD+ |AMD+ |AMD• Up to 3-body term of the products of H, FD, FS
3-body2-body
VT
FD
FD
FD
FD
VT
others...
FD
FD
VT
FS
FS
T
FS
FS
T
3H energy surface
24
∑𝑛=1
𝑁𝐺
𝐶𝑛𝑒−𝑎𝑛𝑟2
• Good convergence for Gaussian numbers NG.• Obtain the saturation property with good radius.
Gaussian expansion
compactwide
Radius=1.76 fm
Three-body term in energy of 3H
25
• No saturation point with one- & two-body terms.• Three-body term has a saturation behavior.
compactwide
3-body term
1& 2-body terms
Full
Radius=1.76 fm
Energy components
EAMD ETOAMD T VC VT VLS PD
3H 16.9 -5.0 37.9 -17.4 -24.1 -1.3 6.4
4He 41.4 -13.3 61.5 -34.9 -38.3 -1.6 7.3
8Be 110.3 -27.6 134.7 -91.0 -69.1 -2.2 9.4
• PD ... D-state probability = [%] • 3H, 4He ... are (0s)3 & (0s)4 with Z=0 (spherical)• 8Be ... is a-a structure.• Need -type correlation to gain the energy more. 26
in MeVpreliminary
in progress
Correlation functions FD, FS in 3H
27
2r2FD 3E
FS 1E
FS 3E
same trendin 3H, 4He, 8Be
• Ranges of and are not short. • Range b of ~ 0.6 bAMD spatially compact
high-k, similar to TOSM
preliminary
28
Summary
• Tensor-Optimized Shell Model (TOSM) using Vbare.– Strong tensor correlation from 0p0h-2p2h involving high-k
components.
– He, Li, Be isotopes : Energy spectra, Radius of n-rich nuclei.– For 8Be, two aspects : grand state region & highly excited states,
which indicates of more configurations, such as aa states.• Tensor-Optimized AMD (TOAMD).
– Two-kinds of correlation functions FD (tensor) & FS (short-range)
– Three-body term contributes to the energy saturation. – Ranges of FD , FS are not short.
– Spatially compact behavior of FD produces high-k component.