• Nenhum resultado encontrado

E.2 Partial wave expansion

E.2.1 D1X/D2 interaction

The interaction is already separable in angular momentum, spin and isospin parts, and reads for one Brink-Booker term

vD1XBB,i(~k, ~k) =(µi

π)3 [Wi+BiPσ−HiPτ −MiPσPτ]e14µ2iq2

≡(µi

π)3 [Wi+BiPσ−HiPτ −MiPσPτ]gi(~k, ~k). (E.34) Therefore, usingEqs. (D.41,A.65,A.70) one gets

hk (LS)JT|vBB,iD1X|k(LS)J Ti=δJJδSSδT Ti

π)3 (kL||e14µ2iq2||k L) p[L]

×

Wi+ (−1)S+1Bi−(−1)T+1Hi−(−1)S+TMi

, (E.35)

UsingEq.(A.95) leads then to

hk (LS)JT|vD1XBB,i|k (LS)J Ti= (−1)LδJJδSSδT TδLL 4πp

[L] (µi

π)3˜giL(k, k)

×

Wi+ (−1)S+1Bi−(−1)T+1Hi−(−1)S+T Mi

. (E.36) E.2.1.2 Density-dependent terms

Density-dependent terms for D1X and D2 in symmetric INM are trivial from this point on. This amounts to substituting in the previous expression for the central terms

i

π)3Li(k, k)

4π →δL0, Wi →t0, Bi →t0x0, Hi =Mi→0. (E.37a) One finds then

hk (LS)JT|vD1Xρ |k (LS)J Ti=δJJδSSδT TδLLδL0t0ρα0

1 + (−1)S+1x0

. (E.38) This term only contributes in the L= 0 channel. On the other hand

hk (LS)JT|vD2ρ |k(LS)J Ti= (−1)LδJJδSSδT TδLL 4πp

[L] (µi

π)3ρα0L3(k, k)

×

W3+ (−1)S+1B3−(−1)T+1H3−(−1)S+T M3

. (E.39) E.2.1.3 Spin-orbit terms

There are both a very long and a very short way to perform the partial wave expansion. One has for both D1X and D2

VD1X/D2so (~k, ~k) =i WLS(~σ1+~σ2)~k ∧~k . (E.40) UsingEqs. (A.5,A.6b), one has

i~k ∧~k= 1

2i~q ∧~q =

√2 2 qq

3 h

Y[1](ˆq)⊗Y[1](ˆq)i[1]

. (E.41)

That is, Eq. (A.11) leads to i~k ∧~k=√

24π 3

X

λ12=1 µ12=1

(−1)λ2kλ11kλ22 12π

p[λ1]![λ2]![µ1]![µ2]!

×h

Y1](ˆk)⊗Y2](ˆk)i[1]

⊗h

Y1](ˆk)⊗Y2](ˆk)i[1][1]

. (E.42)

E.2. Partial wave expansion 127

The two tensors can then be recoupled by analogy to LSJ coupling, then expanded using Eq.(A.12) such that

i~k ∧~k=4π 3

√2 X

λ12=1 µ12=1

(−1)λ2k′λ11kλ22 12π

p[λ1]![λ2]![µ1]![µ2]!

X

f,g

p[1][1][f][g]

×





λ1 λ2 1 µ1 µ2 1

f g 1





hY1](ˆk)⊗Y1](ˆk)i[f]

⊗h

Y2](ˆk)⊗Y2](ˆk)i[g][1]

=4π 3

√2 X

λ12=1 µ12=1

(−1)λ2k′λ11kλ22 12π

p[λ1]![λ2]![µ1]![µ2]!

×X

f,g

p[1][1][f][g]





λ1 λ2 1 µ1 µ2 1

f g 1



hλ110|λ1µ1f0i hλ220|λ2µ2g0i

×

p[λ1][λ2][µ1][µ2] 4πp

[f][g]

hY[f](ˆk)⊗Y[g](ˆk)i[1]

. (E.43)

Hence

(kL||i~k ∧~k||k L) (E.44)

=√

2 X

λ12=1 µ12=1

(−1)λ2kλ11kλ22

× 1

p[λ1]![λ2]![µ1]![µ2]!

p[1][1][L][L]





λ1 λ2 1 µ1 µ2 1 L L 1





×

λ111µ1L0

220|λ2µ2L0i

p[λ1][λ2][µ1][µ2]

p[L][L] (−1)Lp [1]

=3√

6 X

λ12=1 µ12=1

(−1)λ2+Lkλ11kλ22

p[λ1][λ2][µ1][µ2] p[λ1]![λ2]![µ1]![µ2]!





λ1 λ2 1 µ1 µ2 1 L L 1





×

λ111µ1L0

220|λ2µ2L0i . (E.45)

An alternative method is to apply directlyEq.(A.6b), i.e.

i~k ∧~k=√

2kk 4π 3

hY[1](ˆk)⊗Y[1](ˆk)i[1]

. (E.46)

Therefore, usingEq.(A.93)

(kL||i~k ∧~k||k L) =√

2kk

3 (kL||h

Y[1](ˆk)⊗Y[1](ˆk)i[1]

||k L)

=−δL1δL1

2kk 4π 3

p[1]

=−δL1δL1

√2

√3kk. (E.47)

Thus the zero-range spin orbit only acts in the L = 1 partial waves, as it was expected (the angular dependence of~k∧~k is in sin(ˆk·ˆk) which is a Legendre polynomial of first order. The two methods are obviously equivalent, given that

• the terms in Eq.(E.45) corresponding toλ11= 1 and λ22 = 1 imply that one of the Clebsh-Gordan coefficient is zero (if λ11= 1 thenL= 0, thus we must haveL = 1 to have a non-zero 9j, in which caseh1 0 1 0|1 1 1 0i= 0),

• regardless of the values of λ1212, one has two of the summed terms inEq. (E.45) are equal to 0, and two equal to 1, thus

p[λ1][λ2][µ1][µ2] p[λ1]![λ2]![µ1]![µ2]! = 1

2. (E.48)

• forλ12 = 1 andλ21 = 0, the 9jcoefficient inEq.(E.45) indicates thatL=L = 1.

The product of the Clebsh-Gordan coefficients is (maximum coupling)

h1 0 0 0|1 0 1 0i h0 0 1 0|0 1 1 0i= 1. (E.49) UsingEq.(A.3g), one has then

(kL||i~k ∧~k||k L) =(−1)δL1δL1 3√ 6 2 kk







1 0 1 0 1 1 1 1 1



−





0 1 1 1 0 1 1 1 1







=− δL1δL1

√2

√3kk. (E.50)

Thus one has, using the previous comments as well as Eqs. (A.64,A.80) hk (LS)JT|vD1X/D2so |k(LS)J Ti

= 1

p[J]WLShk (LS)JT||(~σ1+~σ2).

i~k ∧~k

||k (LS)J Ti

=(−1)L+S+JδJJδT TWLS

( L S J

S L 1

)

(kL||i~k ∧~k||k L) (S||~σ1+~σ2||S)

=(−1)S+JδJJδT TδL1δL1δS1δS1WLS2√ 6

√2

√3kk

( L S J

S L 1

)

=(−1)1+JδJJδT TδL1δL1kkδS1δS14WLS

( 1 1 J 1 1 1

)

=(−1)JδJJδT TδL1δL1kkδS1δS14WLS(−1)J+34−J(J+ 1) 12

=WLSδJJδT TδL1δL1δS14−J(J+ 1)

3 kk. (E.51)

E.2.1.4 Summary

For the final result one should not forget about exchange terms, which are equal to the direct ones in the expansion (seeSec.A.4.5), so there is an extra 2 factor that should be be carried

E.2. Partial wave expansion 129

on. The latter is not written here to keep consistency with the conventions in the code that computes low-momentum interactions. One finds

VD1X(1S0, k, k) = 1 2π2

X2

i=1

i

π)3i0(k, k)

4π [Wi−Bi−Hi+Mi] + 2t0ρα0 (1−x0), (E.52a) VD1X(3S1, k, k) = 1

2 X2

i=1

i

π)3i0(k, k)

4π [Wi+Bi+Hi+Mi] + 2t0ρα0 (1 +x0), (E.52b)

VD1X(1P1, k, k) =− 1 2π2

X2

i=1

i

π)3i1(k, k) 4π√

3 [Wi−Bi+Hi−Mi], (E.52c) VD1X(3P0, k, k) =− 1

2 X2

i=1

i

π)3i1(k, k) 4π√

3 [Wi+Bi−Hi−Mi] +8

3WLSkk, (E.52d) VD1X(3P1, k, k) =− 1

2 X2

i=1

i

π)3i1(k, k) 4π√

3 [Wi+Bi−Hi−Mi] +4

3WLSkk, (E.52e) VD1X(3P2, k, k) =− 1

2 X2

i=1

i

π)3i1(k, k) 4π√

3 [Wi+Bi−Hi−Mi]−4

3WLSkk, (E.52f)

VD1X(1D2, k, k) = 1 2π2

X2

i=1

i

π)3i2(k, k) 4π√

5 [Wi−Bi−Hi+Mi], (E.52g) VD1X(3D1, k, k) =VD1X(3D2, k, k) =VD1X(3D3, k, k)

= 1 2π2

X2

i=1

i

π)3i2(k, k) 4π√

5 [Wi+Bi+Hi−Mi], (E.52h) where (seeSec.A.3.1)

˜ g0i(k, k)

4π =e14µ2i(k2+k′2) Γi

sh(Γi), (E.53a)

˜ g1i(k, k)

4π√

3 =−e14µ2i(k2+k2)

Γ2iich(Γi)−sh(Γi)), (E.53b)

˜ g2i(k, k)

4π√

5 =e14µ2i(k2+k′2)

Γ3i −3Γich(Γi) + (3 + Γ2i)sh(Γi)

, (E.53c)

Γi =1

2i kk. (E.53d)

Equivalently for D2 VD2(1S0, k, k) = 1

2 X3

i=1

i

π)3i0(k, k)

4π [Wi−Bi−Hi+Mi], (E.54a) VD2(3S1, k, k) = 1

2 X3

i=1

i

π)3i0(k, k)

4π [Wi+Bi+Hi+Mi], (E.54b)

VD2(1P1, k, k) =− 1 2π2

X3

i=1

i

π)3 ˜gi1(k, k) 4π√

3 [Wi−Bi+Hi−Mi], (E.54c) VD2(3P0, k, k) =− 1

2 X3

i=1

i

π)3 ˜gi1(k, k) 4π√

3 [Wi+Bi−Hi−Mi] + 8

3WLSkk, (E.54d) VD2(3P1, k, k) =− 1

2 X3

i=1

i

π)3 ˜gi1(k, k) 4π√

3 [Wi+Bi−Hi−Mi] + 4

3WLSkk, (E.54e) VD2(3P2, k, k) =− 1

2 X3

i=1

i

π)3 ˜gi1(k, k) 4π√

3 [Wi+Bi−Hi−Mi]−4

3WLSkk, (E.54f)

VD2(1D2, k, k) = X3

i=1

i

π)32i(k, k) 4π√

5 [Wi−Bi−Hi+Mi], (E.54g) VD2(3D1, k, k) =VD2(3D2, k, k) =VD2(3D3, k, k)

= 1 2π2

X3

i=1

i

π)3 ˜gi2(k, k) 4π√

5 [Wi+Bi+Hi−Mi], (E.54h) with the convention that ˜gλ3(k, k) includes the extraρα0 factor for simplicity.

E.2.2 vBDRS[X] vertex

The partial wave expansion is performed in unpolarized symmetric nuclear matter, where in- medium dependencies of the coupling constants of v[X]BDRS only relate, when necessary, to ρ0, i.e.

they carry no angular dependency.

E.2.2.1 Central terms

The central terms ofvBDRS interaction are already separated in spin/isospin channels, i.e.

vST,iBDRS(~k, ~k) =CiST0,Λ] (µi

π)3e14µ2iq2 Y

S

Y

T

. (E.55)

UsingEq.(A.75) and the results fromSec. E.2.1.1, one gets easily hk (LS)JT|vBDRSS0T0,i|k(LS)J Ti

= (−1)LδJJδSSδSS0δT TδT T0δLL 4πp

[L] CiS0T00,Λ] (µi

π)3iL(k, k). (E.56) E.2.2.2 Finite-range spin-orbit

We have here

vBDRS1T,so(~k, ~k) =i Cso1T0,Λ]µ2soso√ π)3

2 e14µ2soq2(~σ1+~σ2)·~k∧~k Y

S=1

Y

T

≡i Cso1T0,Λ]µ2soso√ π)3

2 gso(~k, ~k) (~σ1+~σ2)·~k∧~k Y

S=1

Y

T

. (E.57)

E.2. Partial wave expansion 131

Using the same approach than inSec.E.2.1.3for a zero-range spin-orbit, one gets fromEq.(A.43) i e14µ2soq2~k∧~k =√

2kk 4π 3

h

Y[1](ˆk)⊗Y[1](ˆk)i[1]

e14µ2soq2

=√

2kk 4π 3

hY[1](ˆk)⊗Y[1](ˆk)i[1] X

λ

˜

gλso(k, k)h

Y[λ](ˆk)⊗Y[λ](ˆk)i[0]

=√

2kk 4π 3

X

λ

˜

gsoλ (k, k) h

Y[1](ˆk)⊗Y[1](ˆk)i[1]

⊗h

Y[λ](ˆk)⊗Y[λ](ˆk)i[0][1]

=√

2kk 4π 3

X

λ

˜

gsoλ (k, k)X

ab





λ λ 0

1 1 1

a b 1





p[0][1][a][b]

× h

Y[1](ˆk)⊗Y[λ](ˆk)i[a]

⊗h

Y[1](ˆk)⊗Y[λ](ˆk)i[b][1]

=√

2kk 4π 3

X

λ

˜

gsoλ (k, k)X

ab





λ λ 0

1 1 1

a b 1





p[0][1][a][b]

p[λ][λ][1][1]

4πp [a][b]

× hλ0 1 0|λ1a0i hλ0 1 0|λ1b0i h

Y[a](ˆk)⊗Y[b](ˆk)i[1]

=√

6kk X

λ

˜

gλso(k, k)X

ab





λ λ 0

1 1 1

a b 1



[λ]

× hλ0 1 0|λ1a0i hλ0 1 0|λ1b0i h

Y[a](ˆk)⊗Y[b](ˆk)i[1]

. (E.58) Hence, usingEq.(A.93)

(kL||i e14µ2soq2~k∧~k||k L)

= (−1)L3√

2kk X

λ

[λ]˜gsoλ (k, k) 4π





λ λ 0

1 1 1

L L 1





λ0 1 0λ1L0

hλ0 1 0|λ1L0i . (E.59)

Some remarks hold at this point

• one cannot haveL=L = 0 otherwise the 9j coefficient would be zero,

• the product of the Clebsh-Gordan coefficients is non-zero if and only if λ+ 1 +L and λ+ 1 +L are both even. Thta is, Land L must be of same parity. On the other hand, the 9j coefficient requires L =L, L±1, thus L=L, such that the finite-range spin-orbit (i) does not couple between partial waves of different angular momenta, and (ii) acts on all L >1 partial waves,

• in the limitµso →0, that is

gsoλ (~k, ~k) = 1, g˜λso(k, k) = 4π δλ0, (E.60) using Eq.(A.3h) allows to recover the results fromSec.E.2.1.3.

Using the previous remarks one can write (kL||i e14µ2soq2~k∧~k||k L)

=(−1)LδLL3√

2kk X

λ

[λ]g˜λso(k, k) 4π





λ λ 0

1 1 1

L L 1



hλ0 1 0|λ1L0i2

=(−1)LδLL3√

2kk[L]X

λ

[λ]g˜λso(k, k) 4π





λ λ 0

1 1 1

L L 1





λ 1 L

0 0 0

!2

. (E.61)

Thus

hk (LS)JT|v1TBDRS0,so|k (LS)J Ti

= 1

p[J]δJJδT TδT T0Cso1T00,Λ]µ2soso√ π)3 2

× h~k (LS)J||

Y

S0=1

1+~σ2

·

ie14µ2soq2~k ∧~k

||k (LS)Ji

=(−1)L+S+JδJJδT TδT T0Cso1T00,Λ]µ2soso√ π)3 2

×

( L S J

S L 1

)

(kL||ie14µ2soq2~k ∧~k||k L) (S|| Y

S0=1

1+~σ2||S)

=(−1)L+1+JδJJδT TδT T0δSSδS1δLL2√

6Cso1T00,Λ]µ2soso√ π)3 2

( L 1 J

1 L 1

)

×(−1)L3√

2kk[L]X

λ

[λ]˜gsoλ (k, k) 4π





λ λ 0

1 1 1

L L 1





λ 1 L

0 0 0

!2

=(−1)1+JδJJδT TδT T0δSSδS1δLL12√

3Cso1T00,Λ]µ2soso√ π)3 2

( L 1 J

1 L 1

)

×kk[L]X

λ

[λ]g˜λso(k, k) 4π





λ λ 0

1 1 1

L L 1





λ 1 L

0 0 0

!2

. (E.62)

In particular the L = 1 partial wave will involve λ= 0,2 components, whereas in the L = 3 waves one will have λ= 1,3. The finite-range spin-orbit only acts by construction in theS= 1 channel, but if the explicit projectorQ

S0=1 were to be removed, the conclusion would be the same since (~σ1+~σ2) already acts in the S= 1 channel only. Thus theS = 1 projection operator is redundant, but is kept for simplicity.

We provide here the matrix elements for the first partial waves.

1. ForL=L = 1, one gets hk (1S)JT|v1TBDRS0,so|k (1S)J Ti

E.2. Partial wave expansion 133

=(−1)1+JδJJδT TδT T0δSSδS136√

3Cso1T00,Λ]µ2soso√ π)3 2

( 1 1 J 1 1 1

)

×kk X

λ

[λ]˜gλso(k, k) 4π





λ λ 0

1 1 1 1 1 1





λ 1 1 0 0 0

!2

JJδT TδT T0δSSδS13√

3Cso1T00,Λ]µ2soso√ π)3

2 (4−J(J+ 1))kk

×

˜gso0 (k, k) 4π





0 0 0 1 1 1 1 1 1





0 1 1 0 0 0

!2

+ 5˜gso2 (k, k) 4π





2 2 0 1 1 1 1 1 1





2 1 1 0 0 0

!2

JJδT TδT T0δSSδS1Cso1T00,Λ]µ2soso√ π)3

2 (4−J(J+ 1))kk

× 1

3

˜

gso0 (k, k)

4π − 1

3√ 5

˜

g2so(k, k) 4π

. (E.63)

2. ForL=L = 2 one gets

hk (2S)JT|v1TBDRS0,so|k (2S)J Ti

=(−1)1+JδJJδT TδT T0δSSδS160√

3Cso1T00,Λ]µ2soso√ π)3 2

( 2 1 J 1 2 1

)

×kk X

λ

[λ]˜gλso(k, k) 4π





λ λ 0

1 1 1 2 2 1





λ 1 2 0 0 0

!2

JJδT TδT T0δSSδS1

15Cso1T00,Λ]µ2soso√ π)3

2 (−8 +J(J+ 1))kk

×

3g˜so1 (k, k) 4π





1 1 0 1 1 1 2 2 1





1 1 2 0 0 0

!2

+ 7˜gso3 (k, k) 4π





3 3 0 1 1 1 2 2 1





3 1 2 0 0 0

!2

JJδT TδT T0δSSδS1Cso1T00,Λ]µ2soso√ π)3

2 (−8 +J(J+ 1))kk

× 1

5√ 3

˜

gso1 (k, k)

4π − 1

5√ 7

˜

g3so(k, k) 4π

. (E.64)

3. ForL=L = 3

hk (3S)JT|v1TBDRS0,so|k(3S)J Ti

JJδT TδT T0δSSδS1Cso1T00,Λ]µ2soso√ π)3

2 (14−J(J+ 1))kk

× 1

7√ 5

˜

g2so(k, k)

4π − 1

7√ 9

˜

gso4 (k, k) 4π

. (E.65)

4. ForL=L = 4

hk (4S)JT|vBDRS1T0,so|k(4S)J Ti

JJδT TδT T0δSSδS1Cso1T00,Λ]µ2soso√ π)3

2 (−22 +J(J+ 1))kk

× 1

9√ 7

˜

g3so(k, k)

4π − 1

9√ 11

˜

gso5 (k, k) 4π

. (E.66)

5. One can actually extrapolate from the previous results a generic formula for any angular momentum L=L under the form

hk (LS)JT|v1TBDRS0,so|k (LS)J Ti

JJδT TδT T0δSSδS1Cso1T00,Λ]µ2soso√ π)3 2

× (−1)1−L(2 +L(L+ 1)−J(J + 1))kk

×

"

1 [L]p

[L−1]

˜

gsoL−1(k, k)

4π − 1

[L]p [L+ 1]

˜

gL+1so (k, k) 4π

# . (E.67) E.2.2.3 Finite-range tensor

We consider here a generic tensor interaction with an arbitrary form factor f(q), such that the formulæ obtained can be applied for the one-pion exchange andvBDRS[X] . We consider then(2)

vff1T,t(~k, ~k) =g(q)

3 (~σ1·~q) (~σ2·~q)−(~σ1·~σ2) q2 Y

S=1

Y

T

. (E.68)

By construction, and according to Sec.D.1, this tensor should only couple between states of angular momentum L=L±2 because the (~σ1·~σ2) q2 counter term allows to write vff1T,t(~k, ~k) as a combination of Y2m spherical harmonics. One has then using Eqs. (A.5,A.6a)

g(q)

3 (~σ1·~q) (~σ2·~q)−(~σ1·~σ2) q2

=g(q)

9 h

σ[1]1 ⊗q[1]i[0] h

σ2[1]⊗q[1]i[0]

−(~σ1·~σ2) q2

=q2g(q)

12π h

σ[1]1 ⊗Y[1](ˆq)i[0] h

σ[1]2 ⊗Y[1](ˆq)i[0]

−(~σ1·~σ2)

=q2g(q)

12πX

f

p[0][0][f][f]





1 1 f 1 1 f 0 0 0





×h

σ1[1]⊗σ2[1]i[f] h

Y[1](ˆq)⊗Y[1](ˆq)i[f]

−(~σ1·~σ2)

2In the case of a one-pion exchange, the isospin projection operatorQ

T has to be replaced byτ1·τ2.

E.2. Partial wave expansion 135

=12π q2g(q) X

f

[f]





1 1 f 1 1 f 0 0 0





p[1][1]

p4π[f] h1 0 1 0|1 1f0i

×h

σ[1]1 ⊗σ2[1]i[f]

⊗Y[f](ˆq) [0]

−q2g(q) (~σ1·~σ2)

=12π q2g(q) X

f

[f](−1)f p[f]

( 1 1 f 1 1 0

) p

[f] 1 1 f 0 0 0

! 3 p4π[f]

×h

σ[1]1 ⊗σ2[1]i[f]

⊗Y[f](ˆq) [0]

−q2g(q) (~σ1·~σ2)

=12π q2g(q) X

f

[f] (−1)f (−1)f p[1][1]

1 1 f 0 0 0

! 3 p4π[f]

×h

σ[1]1 ⊗σ2[1]i[f]

⊗Y[f](ˆq) [0]

−q2g(q) (~σ1·~σ2)

=12π q2g(q) X

f

p[f] 1 1 f 0 0 0

! 1

√4π

×h

σ[1]1 ⊗σ[1]2 i[f]

⊗Y[f](ˆq) [0]

−q2g(q) (~σ1·~σ2) . (E.69) The 3j coefficient requires f = 0,1,2. However

• the~σ1·~σ2 factor exactly cancels out thef = 0 component, since

12π 1 1 0

0 0 0

! 1

√4π

[1]1 ⊗σ2[1]i[0]

⊗Y[0](ˆq) [0]

=− 3

√3

1[1]⊗σ2[1]i[0]

=~σ1·~σ2, (E.70)

• forf = 1 the 3j coefficient is zero.

Thus we only havef = 2(3). One has then hk(LS)JT|v1Tff 0,t|k(LS)J Ti

JJδT TδT T012π√

5 1 1 2

0 0 0

! 1 p[j]

√1 4π

×(k(LS)J||q2g(q) h

σ[1]1 ⊗σ[1]2 i[2]

⊗Y[2](ˆq) [0]

||k(LS)J)

JJδT TδT T0

√6√ p 4π

[J]

×(k(LS)J||q2g(q) h

σ[1]1 ⊗σ[1]2 i[2]

⊗Y[2](ˆq) [0]

||k(LS)J). (E.71)

3This was expected by construction of the operatorS12which is proportional toY2.

We need thus to evaluate (k(LS)J||q2g(q)h

σ[1]1 ⊗σ[1]2 i[2]

⊗Y[2](ˆq) [0]

||k(LS)J)

=p

[J][J][0]





L L 2 S S 2 J J 0



(kL||q2g(q)Y[2](ˆq)||k L) (S||h

σ[1]1 ⊗σ[1]2 i[2]

||S)

JJ p[J] p[2]

( L S J

S L 2

)

(kL||q2g(q)Y[2](ˆq)||k L) (S||h

σ[1]1 ⊗σ2[1]i[2]

||S), (E.72) where fromEq. (A.81)

(S||h

σ[1]1 ⊗σ[1]2 i[2]

||S) = 6p

[2][S][S]





1/2 1/2 1 1/2 1/2 1

S S 2



. (E.73)

Thus the 9j coefficient is only non-zero when S=S = 1. As expected, the finite-range tensor only acts in the spin-triplet partial waves and theS0 = 1 projector in this term is also redundant.

We have then

(S||h

σ1[1]⊗σ[1]2 i[2]

||S) = 6δSSδS1p

[2][1][1]





1/2 1/2 1 1/2 1/2 1

1 1 2



=δSSδS12√

5. (E.74)

On the other hand, we can use the same decoupling-recoupling method from Sec.E.2.2.2 to obtain

(kL||q2g(q)Y[2](ˆq)||k L)

= X

µ12=2

s 4π[2]!

1]![µ2]!(−1)µ2kµ1kµ2(kL||g(q) h

Y1](ˆk)⊗Y2](ˆk)i[2]

||k L)

= X

µ12=2

s 4π[2]!

1]![µ2]!(−1)µ2kµ1kµ2

×X

λ

˜

gλ(q)(kL||h

Y[λ](ˆk)⊗Y[λ](ˆk)i[0] h

Y1](ˆk)⊗Y2](ˆk)i[2]

||k L)

= X

µ12=2

s 4π[2]!

1]![µ2]!(−1)µ2kµ1kµ2

×X

λ

˜

gλ(q)(kL||h

Y[λ](ˆk)⊗Y[λ](ˆk)i[0]

⊗h

Y1](ˆk)⊗Y2](ˆk)i[2][2]

||k L)

= X

µ12=2

s 4π[2]!

1]![µ2]!(−1)µ2kµ1kµ2 X

λ

˜

gλ(q)X

a,b





λ λ 0

µ1 µ2 2

a b 2





p[a][b][0][2] (E.75)

×(kL||h

Y[λ](ˆk)⊗Y1](ˆk)i[a]

⊗h

Y[λ](ˆk)⊗Y2](ˆk)i[b][2]

||k L)

E.2. Partial wave expansion 137

= X

µ12=2

s 4π[2]!

1]![µ2]!(−1)µ2kµ1kµ2 X

λ

˜

gλ(q)X

a,b





λ λ 0

µ1 µ2 2

a b 2





p[a][b][0][2] (E.76)

×

p[λ][µ1][λ][µ2] 4πp

[a][b] (kL||h

Y[a](ˆk)⊗Y[b](ˆk)i[2]

||k L)

× hλ0µ10|λ µ1a0i hλ0µ20|λ µ2b0i

=[2] (−1)L (4π)3/2

X

µ12=2

s[2]![µ1][µ2]

1]![µ2]! (−1)µ2kµ1kµ2 X

λ

[λ] ˜gλ(q)





λ λ 0

µ1 µ2 2 L L 2





×

λ0µ10λ µ1L0

hλ0µ20|λ µ2L0i. (E.77) Some comments can be made here and allow to recover generic features associated with tensor coupling:

• as expected, the tensor couples between partial waves such as|L−L| ≤2, otherwise the 6j coefficient would be zero,

• one cannot haveL=L = 0, thus the tensor does not act on L=L = 0 partial waves,

• ifµ1 = 0 thenµ2= 2 andλ=L. To have L 2 L

0 0 0

!

to be non-zero,LandL have to be of same parity. Same goes if µ12 = 1 to have a non-zero product of 3j symbols. As expected, the tensor term only couples a partial wave of angular momentumL to partial waves L =L, L±2, except forL=L = 0.

Finally, one obtains

hk(LS)JT|vff1T0,t|k(LS)J Ti

JJδT TδT T0δSSδS1 10√ 6 4π (−1)L

( L S J

S L 2

)

× X

µ12=2

s[2]![µ1][µ2]

1]![µ2]! (−1)µ2kµ1kµ2 X

λ

[λ] ˜gλ(q)





λ λ 0

µ1 µ2 2 L L 2





×

λ0µ10λ µ1L0

hλ0µ20|λ µ2L0i . (E.78) Like in the finite-range spin-orbit case, we provide here the explicit contributions we are interested in.

1. ForL=L = 1, three terms are to be considered, i.e.

• µ12= 1, in which caseλ= 0,2, and hk(1S)JT|vff1T0,t|k(1S)J Ti

JJδT TδT T0δSSδS1

10√ 6 4π

( 1 1 J 1 1 2

) s[2]![1][1]

[1]![1]! kk

×

[0] ˜g0(q)





0 0 0 1 1 2 1 1 2



h0 0 1 0|0 1 1 0i h0 0 1 0|0 1 1 0i

+ [2] ˜g2(q)





2 2 0 1 1 2 1 1 2



h2 0 1 0|2 1 1 0i h2 0 1 0|2 1 1 0i

JJδT TδT T0δSSδS1

( 1 1 J 1 1 2

) kk

5

π ˜g0(q) + 1 π√

5g˜2(q)

, (E.79)

• µ1= 0, µ2 = 2, in which caseλ= 1, and hk(1S)JT|v1Tff 0,t|k(1S)J Ti

=−δJJδT TδT T0δSSδS110√ 6 4π

( 1 1 j 1 1 2

) s[2]![0][2]

[0]![2]! k2

×[1] ˜g1(q)





1 1 0 0 2 2 1 1 2



h1 0 0 0|1 0 1 0i h1 0 2 0|1 2 1 0i

JJδT TδT T0δSSδS1

( 1 1 J 1 1 2

) k2

√3

π ˜g1(q), (E.80)

• µ1= 2, µ2 = 0, in which caseλ= 1, and immediately hk(1S)JT|vff1T0,t|k(1S)J Ti=δJJδT TδT T0δSSδS1

( 1 1 J 1 1 2

) k2

√3 π g˜1(q).

(E.81) 2. ForL=L = 2, one has also three terms to evaluate, i.e.

• µ12= 1, in which caseλ= 1,3, and hk(2S)JT|v1Tff 0,t|k(2S)J Ti

=−δJJδT TδT T0δSSδS1 10√ 6 4π

( 2 1 J 1 2 2

) s[2]![1][1]

[1]![1]! kk

×

[1] ˜g1(q)





1 1 0 1 1 2 2 2 2



h1 0 1 0|1 1 2 0i h1 0 1 0|1 1 2 0i

+ [3] ˜g3(q)





3 3 0 1 1 2 2 2 2



h3 0 1 0|3 1 2 0i h3 0 1 0|3 1 2 0i

E.2. Partial wave expansion 139

JJδT TδT T0δSSδS1

( 2 1 J 1 2 2

) kk

√15

π g˜1(q) + 3√ 5 π√

7˜g3(q)

, (E.82)

• µ1 = 0, µ2 = 2, in which caseλ= 2, and hk(2S)JT|vff1T,t|k(2S)J Ti

JJδT TδT T0δSSδS110√ 6 4π

( 2 1 J 1 2 2

) s[2]![0][2]

[0]![2]! k2

×[2] ˜g2(q)





2 2 0 0 2 2 2 2 2



h2 0 0 0|2 0 2 0i h2 0 2 0|2 2 2 0i

=−δJJδT TδT T0δSSδS1

( 2 1 J 1 2 2

) k2

√15 π√

7˜g2(q), (E.83)

• µ1 = 2, µ2 = 0, in which caseλ= 1, and immediately hk(2S)JT|vff1T0,t|k(2S)J Ti=−δJJδT TδT T0δSSδS1

( 1 1 J 1 1 2

) k2

√15 π√

7g˜2(q). (E.84) 3. For the coupled channels L = 0, L= 2, one has λ=µ2, the 6j coefficient

( 2 1 J 1 0 2

) is non-zero if and only ifJ = 1 because of the triangle rule. This means the only diagonal coupling to be considered will be3S1-3D1. We have then

• In the caseµ12 = 1,λ= 1 and hk(0S)JT|vff1T0,t|k(2S)J Ti

=−δJJδJ1δT TδT T0δSSδS1

10√ 6 4π

( 2 1 1 1 0 2

) s[2]![1][1]

[1]![1]! kk

×[1] ˜g1(q)





1 1 0 1 1 2 2 0 2



h1 0 1 0|1 1 2 0i h1 0 1 0|1 1 0 0i

JJδJ1δT TδT T0δSSδS1kk

√2 π√

3g˜1(q), (E.85)

• In the caseµ1 = 2, µ2 = 0,λ= 2 and hk(2S)JT|v1Tff 0,t|k(0S)J Ti

JJδJ1δT TδT T0δSSδS1 10√ 6 4π

( 2 1 1 1 0 2

) s[2]![0][2]

[0]![2]! k2

×[2] ˜g2(q)





2 2 0 2 0 2 0 2 2



h2 0 0 0|2 0 2 0i h2 0 2 0|2 2 0 0i

JJδJ1δT TδT T0δSSδS1k2 1 π√

10g˜2(q), (E.86)

• In the caseµ1 = 0, µ2 = 2, one has λ= 0 and hk(0S)JT|vff1T0,t|k(2S)J T)

JJδJ1δT TδT T0δSSδS1 10√ 6 4π

( 2 1 1 1 0 2

) s[2]![0][2]

[0]![2]! k2

×[0] ˜g0(q)





0 0 0 0 2 2 0 2 2



h0 0 2 0|0 2 2 0i h0 0 0 0|0 0 0 0i

JJδJ1δT TδT T0δSSδS1k2 1 π√

2g˜0(q). (E.87)

4. Finally for the coupled channelsL= 0, L = 2, one simply has to invert the roles ofkand k in theL= 2, L = 0 case.

There seems to be a general relation for these reduced matrix elements. Indeed, one can write

• forL=L

hk(LS)JT|vff1T0,t|k(LS)J Ti

=(−1)L+1δJJδT TδT T0δSSδS1F1(L, J)

×

[L+ 1]kkL−1(q) 4πp

[L−1]+ [L] (k2+k2) ˜gL(q) 4πp

[L] + [L−1]kk ˜gL+1(q)

4πp

[L+ 1]

, (E.88)

where

F1(L, J) =

( L 1 J 1 L 2

) 2√ 30p

L(L+ 1)

p[L−1] [L] [L+ 1], (E.89)

• forL=L+ 2, one necessarily hasJ =L+ 1, and hk(LS)JT|vff1T0,t|k(L+ 2S)J Ti

=(−1)LδJJδT TδT T0δSSδS1F2(L)

× k2

2

˜ gL(q) 4πp

[L]+kk ˜gL+1(q) 4πp

[L+ 1]+k′2 2

˜ gL+2(q) 4πp

[L+ 2]

, (E.90)

where

F2(L) = 12p

(L+ 1)(L+ 2)

[L+ 2] . (E.91)

E.2.2.4 One-pion exchange

For reference, we provide a partial wave decomposition of the one-pion exchange, whose associated vertex reads in momentum space

vπ(~q) =−4π gA

√2fπ

2

(~τ1·~τ2)(~σ1·~q) (~σ2·~q) q22

=−4π gA

√2fπ

2

(~τ1·~τ2) 1 q22

(~σ1·~q) (~σ2·~q)−1

3q2 (~σ1·~σ2) + 1

3q2 (~σ1·~σ2)

. (E.92)

E.2. Partial wave expansion 141

To achieve this, we need to decompose in partial waves the counter term

vctπ(~k, ~k) =g(q)q2 (~σ1·~σ2) (~τ1·~τ2) , (E.93) which is trivial. Indeed, letG(q) =q2g(q), one has then

hk(LS)JT|vπct|k(LS)J Ti

JJδT TδSSX

λ

λ(q) 1

p[L](kL||h

Y[λ](ˆk)⊗Y[λ](ˆk)i[0]

||k L)

×(2S(S+ 1)−3) (2T(T + 1)−3)

=(−1)L+S+TδJJδT TδSSδLLl(q) 4π

p1

[L] (2S(S+ 1)−3) (2T(T + 1)−3)

=−δJJδT TδSSδLLl(q) 4π

p1

[L] (2S(S+ 1)−3) (2T(T + 1)−3). (E.94) For the one-pion exchange vπ, one introduces (seeSec. A.3.5)

pf(~k, ~k)≡ q2 q2+m2π

1

qf , (E.95)

in which case

g(q) =−4π 3

gA

√2fπ 2

1

q22 ≡ −4π 3

gA

√2fπ 2

p2(~k, ~k), (E.96a) G(q) =−4π

3

gA

√2fπ

2

q2

q22 ≡ −4π 3

gA

√2fπ

2

p0(~k, ~k). (E.96b) Thus after some manipulations, without the extra 2 factor for the exchange terms

vπ(1S0, k, k) =vπ(3S1, k, k)

=−(4π)2 gA

√2fπ

200(k, k)

4π , (E.97a)

vπ(1P1, k, k) =3 (4π)2 gA

√2fπ 2

˜ p01(k, k)

4π√

3 , (E.97b)

vπ(3P0, k, k) =(4π)2 3

gA

√2fπ

2

˜ p01(k, k)

4π√ 3

−(4π)2 3

gA

√2fπ

2 4 3

5kk20(k, k)

4π + 3(k2+k2)p˜21(k, k) 4π√

3 +kk22(k, k) 4π√

5

, (E.97c) vπ(3P1, k, k) =(4π)2

3

gA

√2fπ

201(k, k) 4π√

3

−(4π)2 3

gA

√2fπ 2

4 6

5kk20(k, k)

4π + 3(k2+k2)p˜21(k, k) 4π√

3 +kk22(k, k) 4π√

5

, (E.97d) vπ(3P2, k, k) =(4π)2

3

gA

√2fπ 2

˜ p01(k, k)

4π√ 3

−(4π)2 3

gA

√2fπ 2

4 30

5kk20(k, k)

4π + 3(k2+k2)p˜21(k, k) 4π√

3 +kk22(k, k) 4π√

5

, (E.97e)

vπ(1D2, k, k) =−(4π)2 gA

√2fπ 2

˜ p02(k, k)

4π√

5 , (E.97f)

vπ(3D1, k, k) =−(4π)2 gA

√2fπ 2

˜ p02(k, k)

4π√ 5

−(4π)2 gA

√2fπ

2

4 10

7kk21(k, k) 4π√

3 + 5(k2+k2)p˜22(k, k) 4π√

5 + 3kk23(k, k) 4π√

7

, (E.97g) vπ(3D2, k, k) =−(4π)2

gA

√2fπ

202(k, k) 4π√

5

−(4π)2 gA

√2fπ 2 4

10

7kk21(k, k) 4π√

3 + 5(k2+k2)p˜22(k, k) 4π√

5 + 3kk23(k, k) 4π√

7

, (E.97h) vπ(3D3, k, k) =−(4π)2

gA

√2fπ 2

˜ p02(k, k)

4π√ 5

−(4π)2 gA

√2fπ 2

4 35

7kk21(k, k) 4π√

3 + 5(k2+k′2)p˜22(k, k) 4π√

5 + 3kk23(k, k) 4π√

7

, (E.97i)

vπ1, k, k) =(4π)2 gA

√2fπ 2

4π√ 2

1

2k220(k, k)

4π +kk21(k, k) 4π√

3 +1

2k222(k, k) 4π√

5

,

(E.97j) where

˜ p00(k, k)

4π =1 + m2π 4kk ln

m2π+ (k−k)2 m2π+ (k+k)2

, (E.98a)

˜ p01(k, k)

4π√

3 =− m2π

2kk −m2π(k2+k2+m2π) 8k2k2 ln

m2π+ (k−k)2 m2π+ (k+k)2

, (E.98b)

˜ p02(k, k)

4π√

5 =3m2π(k2+k2+m2π) 8k2k2 + m2π

2kk −1

4+3m2π(k2+k′2+m2π) 16k2k2

! ln

m2π+ (k−k)2 m2π+ (k+k)2

, (E.98c)

˜ p20(k, k)

4π =− 1

4kk ln

m2π+ (k−k)2 m2π+ (k+k)2

, (E.98d)

˜ p21(k, k)

4π√

3 = 1

2kk +(k2+k2+m2π) 8k2k2 ln

m2π+ (k−k)2 m2π+ (k+k)2

, (E.98e)

˜ p22(k, k)

4π√

5 =−3 (k2+k2+m2π) 8k2k2 − 1

4kk −1

2+ 3 (k2+k2+m2π)2 8k2k2

! ln

m2π+ (k−k)2 m2π+ (k+k)2

, (E.98f)

˜ p23(k, k)

4π√

7 =− 1 kk

1

3−5 (k2+k2+m2π)2 16k2k′2

!

−(k2+k2+m2π)

16k2k2 3− 5 (k2+k2+m2π)2 4k2k2

! ln

m2π+ (k−k)2 m2π+ (k+k)2

. (E.98g)

E.2. Partial wave expansion 143

E.2.2.5 Summary

Using the previous work, matrix elements in theL≤2 partial waves for vBDRS[X] read vBDRS[X] (1S0, k, k) = 1

2 XN

i=1

Ci010,Λ] (µi

π)3i0(k, k)

4π , (E.99a)

vBDRS[X] (3S1, k, k) = 1 2π2

XN

i=1

Ci100,Λ] (µi

π)3i0(k, k)

4π , (E.99b)

v[X]BDRS(1P1, k, k) = 1 2π2

XN

i=1

Ci000,Λ] (µi

π)3i1(k, k) 4π√

3 , (E.99c)

v[X]BDRS(3P0, k, k) = 1 2π2

XN

i=1

Ci110,Λ] (µi

π)3i1(k, k) 4π√

3 + 4 1

2Cso110,Λ]µ2soso√ π)3

2 kk

1 3

˜

gso0 (k, k)

4π −1

3

˜

g2so(k, k) 4π√

5

(E.99d)

− 1

2Ct110,Λ]µ4tt√ π)3 4

×4 3

5˜gt0(k, k)

4π kk+ 3 (k2+k2)g˜1t(k, k) 4π√

3 +g˜2t(k, k) 4π√

5 kk

,

v[X]BDRS(3P1, k, k) = 1 2π2

XN

i=1

Ci110,Λ] (µi

π)3i1(k, k) 4π√

3 + 2 1

2Cso110,Λ]µ2soso√ π)3

2 kk

1 3

˜

gso0 (k, k)

4π −1

3

˜

g2so(k, k) 4π√

5

(E.99e)

− 1

2Ct110,Λ]µ4tt√ π)3 4

×2 3

5˜gt0(k, k)

4π kk+ 3 (k2+k2)g˜1t(k, k) 4π√

3 +g˜2t(k, k) 4π√

5 kk

,

v[X]BDRS(3P2, k, k) = 1 2π2

XN

i=1

Ci110,Λ] (µi

π)3i1(k, k) 4π√

3

−2 1

2Cso110,Λ]µ2soso√ π)3

2 kk

1 3

˜

gso0 (k, k)

4π −1

3

˜

g2so(k, k) 4π√

5

(E.99f)

− 1

2Ct110,Λ]µ4tt√ π)3 4

× 2 15

5g˜t0(k, k)

4π kk+ 3 (k2+k2)˜g1t(k, k) 4π√

3 +g˜2t(k, k) 4π√

5 kk

,

vBDRS[X] (1D2, k, k) = 1 2π2

XN

i=1

Ci010,Λ] (µi

π)3i2(k, k) 4π√

5 , (E.99g)

vBDRS[X] (3D1, k, k) = 1 2π2

XN

i=1

Ci100,Λ] (µi

π)3i2(k, k) 4π√

5

−6 1

2Cso100,Λ]µ2soso√ π)3 2

kk 5

˜g1so(k, k) 4π√

3 − g˜3so(k, k) 4π√

7

(E.99h) + 1

2Ct100,Λ]µ4tt√ π)3 4

×2 5

7kkt1(k, k) 4π√

3 + 5(k2+k2)g˜2t(k, k) 4π√

5 + 3kk ˜gt3(k, k) 4π√

7

,

vBDRS[X] (3D2, k, k) = 1 2π2

XN

i=1

Ci100,Λ] (µi

π)3i2(k, k) 4π√

5

−2 1

2Cso100,Λ]µ2soso√ π)3 2

kk 5

˜g1so(k, k) 4π√

3 − g˜3so(k, k) 4π√

7

(E.99i) + 1

2Ct100,Λ]µ4tt√ π)3 4

×2 5

7kkt1(k, k) 4π√

3 + 5(k2+k2)g˜2t(k, k) 4π√

5 + 3kk ˜gt3(k, k) 4π√

7

,

vBDRS[X] (3D3, k, k) = 1 2π2

XN

i=1

Ci100,Λ] (µi

π)3i2(k, k) 4π√

5 + 4 1

2Cso100,Λ]µ2soso√ π)3 2

kk 5

˜g1so(k, k) 4π√

3 − g˜3so(k, k) 4π√

7

(E.99j) + 1

2Ct100,Λ]µ4tt√ π)3 4

× 4 35

7kk1t(k, k) 4π√

3 + 5(k2+k2)g˜2t(k, k) 4π√

5 + 3kkt3(k, k) 4π√

7

,

vBDRS[X] (3F2, k, k) = 1 2π2

XN

i=1

Ci110,Λ] (µi

π)3i3(k, k) 4π√

5 + 1

2Cso110,Λ]µ2soso√ π)3 2 kk 8

7

˜g2so(k, k) 4π√

5 − g˜4so(k, k) 4π√

9

(E.99k)

− 1

2Ct110,Λ]µ4tt√ π)3 4

× 8 35

9kk2t(k, k) 4π√

5 + 7(k2+k2)g˜3t(k, k) 4π√

7 + 5kkt4(k, k) 4π√

9

,

vBDRS[X] (3G3, k, k) = 1 2π2

XN

i=1

Ci100,Λ] (µi

π)3i4(k, k) 4π√

5

− 1

2Cso100,Λ]µ2soso√ π)3 2 kk 10

9

˜gso3 (k, k) 4π√

7 − g˜5so(k, k) 4π√

11

(E.99l) + 1

2Ct100,Λ]µ4tt√ π)3 4

×10 63

11kk3t(k, k) 4π√

7 + 9(k2+k2)˜g4t(k, k) 4π√

9 + 7kk5t(k, k) 4π√

11

,

E.2. Partial wave expansion 145

vBDRS[X]1, k, k) =− 1

2Ct100,Λ]µ4tt√ π)3 4

× 4√ 2

1

2k2t0(k, k)

4π +kk ˜gt1(k, k) 4π√

3 +1

2k2t2(k, k) 4π√

5

,

(E.99m) vBDRS[X]2, k, k) = + 1

2Ct110,Λ]µ4tt√ π)3 4

×12√ 6 5

1

2k2 ˜g1t(k, k) 4π√

3 +kk2t(k, k) 4π√

5 +1

2k2 ˜g3t(k, k) 4π√

7

,

(E.99n) vBDRS[X]3, k, k) =− 1

2Ct100,Λ]µ4tt√ π)3 4

×24√ 3 7

1

2k2 ˜g2t(k, k) 4π√

5 +kk3t(k, k) 4π√

7 +1

2k2 ˜g4t(k, k) 4π√

9

,

(E.99o) where

˜ gi0(k, k)

4π =e14µ2i(k2+k′2)

Γi sh(Γi), (E.100a)

˜ gi1(k, k)

4π√

3 =−e14µ2i(k2+k′2) Γ2i

Γich(Γi)−sh(Γi)

, (E.100b)

˜ gi2(k, k)

4π√

5 =e14µ2i(k2+k2) Γ3i

−3Γich(Γi) + (3 + Γ2i)sh(Γi)

, (E.100c)

˜ gi3(k, k)

4π√

7 =−e14µ2i(k2+k′2) Γ4i

Γi(15 + Γ2i) ch(Γi)−3 (5 + 2Γ2i)sh(Γi)

, (E.100d)

˜ gi4(k, k)

4π√

9 =e14µ2i(k2+k′2) Γ5i

−5Γi(21 + 2Γ2i)ch(Γi) + (105 + 45Γ2i + Γ4i)sh(Γi)

, (E.100e)

˜ gi5(k, k)

4π√

11 =−e14µ2i(k2+k′2) Γ6i

Γi(945 + 105Γ2i + Γ4i)ch(Γi)−15(63 + 28Γ2i + Γ4i)sh(Γi) , (E.100f) Γi=1

2i kk. (E.100g)

147

Appendix F

Utilities for fitpack

Abstract: This chapter presents different objects that are used in fitpack, i.e. as standard benchmark cost functions or the algorithm for generating random curves and surfaces.

Contents

F.1 Benchmarking cost functions . . . 147 F.1.1 Unimodal functions . . . 147 F.1.2 Multimodal functions with many local optima. . . 149 F.1.3 Multimodal functions with few local optima . . . 154 F.2 Random surface generator . . . 156 F.2.1 One-dimension case . . . 157 F.2.2 Two-dimension case . . . 161

F.1 Benchmarking cost functions

To evaluate the performances of the simplex andfitpack algorithms, several cost functionsfi have been considered [55], corresponding to different situations in terms of (i) the existence of secondary minima (multimodal functions), (ii) the smoothness of the cost surface around the global minimum, and (iii) the dimensionality. For some of them we represent the surface in the two-dimension case for illustration purpose. n corresponds to the dimension of the problem, and the absolute optimum will be notedx. We also suggest values for the initial search space that are large enough to catch the complexity of the problem.

F.1.1 Unimodal functions

Unimodal functions are rather easy to optimize, although the problem becomes complex when the dimension increases.

• The so-called sphere functionf1 is defined as a simple sum of squares, i.e.

f1(x)≡ Xn

i=1

x2i , (F.1a)

xi∈[−100,+100], xi = 0, f1(x) = 0. (F.1b)

Figure F.1: The sphere function f1 forn= 2.

• The function f2 is defined as f2(x)≡

Xn

i=1

|xi|+ Yn

i=1

|xi|, (F.2a)

xi∈[−10,+10], xi = 0, f2(x) = 0. (F.2b)

• The function f3 is defined as a Schwefels’s double sum function [56]. Its gradient is not oriented along the principal axis due to the epistasis among their variables, such that any algorithms that use the gradient converges very slowly.

f3(x)≡ Xn

i=1

 Xi

j=1

xj

2

, (F.3a)

xi∈[−65,+65], xi = 0, f3(x) = 0. (F.3b)

• The function f4 is defined as f4(x)≡max

i |xi|, (F.4a)

xi ∈[−100,+100], xi = 0, f4(x) = 0. (F.4b)

• The functionf5corresponds to Rosenbrock’s function [57], which is unimodal forn >3, and multimodal forn≤3. The global minimum is inside a long, narrow, parabolic-shaped flat valley, which is whyf5 is often called Rosenbrock’s valley function. Due to the non-linearity of the valley, many algorithms converge slowly because they change the direction of the search repeatedly. To find the valley is trivial, however to converge to the global minimum is difficult. One has then

f5(x)≡

n−1X

i=1

100(xi+1−x2i)2+ (xi−1)2

, (F.5a)

xi∈[−30,+30], xi = 1, f5(x) = 0. (F.5b)

F.1. Benchmarking cost functions 149

Figure F.2: The Rosenbrock’s function f5 forn= 2.

• The function f6 corresponds to a discontinuous step function, defined as f6(x)≡

Xn

i=1

(⌊xi+ 0.5⌋) , (F.6a)

xi ∈[−100,+100], xi ∈[0,0.5), f6(x) = 0. (F.6b) F.1.2 Multimodal functions with many local optima

This class of functions corresponds to the most complex optimization problems, since they contain many metastable traps that must be avoided.

• The function f7 corresponds to Salomon’s function, i.e.

f7(x)≡ −cos

2π vu ut

Xn

i=1

x2i

+ 1 10

vu ut

Xn

i=1

x2i + 1, (F.7a)

xi∈[−100,+100], xi = 0, f7(x) = 0. (F.7b)

• The function f8 corresponds to the normalized Schwefel’s function [56], where the global minimum is geometrically distant, over the parameter space, from the next best local

minima. Therefore, search algorithms are potentially prone to convergence in the wrong direction. It reads

f8(x)≡1 n

Xn

i=1

−xi sin(p

|xi|) + 418.982887272(...), (F.8a) xi∈[−500,+500], xi = 420.968746(...), f8(x) = 0. (F.8b)

Figure F.3: The Schwefel’s functionf8 forn= 2.

• The function f9 is defined as the highly multimodal Rastrigin’s function [58], i.e.

f9(x)≡ Xn

i=1

x2i −10 cos(2π xi) + 10

, (F.9a)

xi ∈[−5.12,+5.12], xi = 0, f9(x) = 0. (F.9b)

F.1. Benchmarking cost functions 151

Figure F.4: The Rastringin’s functionf9 forn= 2.

• The function f10 corresponds to Whitley’s function defined as f10(x)≡

Xn

i=1

Xn

j=1

(100(x3i −xj)2+ (1−xj))2

4000 −cos 100(x3i −xj)2+ (1−xj)2 + 1

, (F.10a) xi∈[−500,+500], xi = 1, f10(x) = 0. (F.10b)

• The function f11 is the Griewank’s function that reads f11(x)≡ 1

4000 Xn

i=1

x2i − Yn

i=1

cos xi

√i

+ 1, (F.11a)

xi∈[−500,+500], xi = 0, f11(x) = 0. (F.11b)

Figure F.5: The Griewank’s function f11 forn= 2.

• the generalized penalized functions f12and f13 are defined as f12(x)≡π

30

"

10 sin2(π y1) +

n−1X

i=1

(yi−1)2(1 + 10 sin2(π yi+1)) + (yn−1)2

# ,

(F.12a) xi ∈[−50,+50], xi =−1, f12(x) = 0, (F.12b) u(x, a, k, m) =





k(x−a)m, x > a ,

0, −a≤x≤a ,

k(−x−a)m, −a > x ,

yi = 1 +xi+ 1

4 , (F.12c)

and

f13(x)≡ 1 10

10 sin2(3π x1) +

n−1X

i=1

(xi−1)2(1 + sin2(3π xi+1))

+ (xn−1)2(1 + sin2(2π xn))

, (F.13a) xi ∈[−500,+500], xi = 1, f13(x) = 0. (F.13b)

• The function f14 corresponds to Ackley’s function [59] that reads f14(x)≡ −20 exp

"

−0.2 r1

n Xn

i=1

x2i

#

−exp

"

1 n

Xn

i=1

cos(2π xi)

#

+ 20 +e , (F.14a) xi∈[−32,+32], xi = 0, f14(x) = 0. (F.14b)

F.1. Benchmarking cost functions 153

Figure F.6: The Ackley’s function f14 forn= 2.

• The function f15 is Easom’s function defined in two dimension, i.e.

f15(x)≡ −cos(x1) cos(x2) exp[−(x1−π)2−(x2−π)2], (F.15a) xi∈[−100,+100], xi =π , f15(x) =−1. (F.15b)

Figure F.7: The Easom’s function f15.

F.1.3 Multimodal functions with few local optima

• The functionf16 is defined as Hump’s ”camel back” function, which posseses two global optima in two dimension, i.e.

f16(x)≡

4−2.1x22+x41 3

x21+x1x2+ (4x22−4)x22, (F.16a)

xi∈[−5,+5], (F.16b)

x=[0.089842(...),−0.712656(...)],[−0.089842(...),0.712656(...)], (F.16c)

f15(x) =−1.031628453(...). (F.16d)

Figure F.8: The Hump’s function f16.

• The functionf17 is Branin’s function, which posseses three global optima in two dimension, i.e.

f17(x)≡

x2− 5.1

2x21+ 5 πx1−6

2

+ 10

1− 1 8π

cos(x1) + 10, (F.17a)

x1∈[−5,+10], x2 ∈[0,+15], (F.17b)

x =[−π,12.275(...)],[π,2.275(...)],[9.4278(...),2.475(...)], (F.17c)

f17(x) =0.397887346(...). (F.17d)

F.1. Benchmarking cost functions 155

Figure F.9: The Branin’s functionf17.

• The functions f18, f19 and f20 corresponds to Shekel’s foxhole functions in four dimen- sion [60], form= 5, 7 and 10, respectively, where

f17/18/19(x)≡ − Xm

i=1

P4 1

j=1(xj−aij)2+ci

, (F.18a)

xi ∈[−10,+10], x = [4,4,4,4], (F.18b)

f17(x) =−10.1422(...), f18(x) =−10.3909(...), f19(x) =−10.5300(...). (F.18c) where the various coefficients are defined in Tab.{F.1}.

i 1 2 3 4 5 6 7 8 9 10

ai1 4 1 8 6 3 2 5 8 6 7

ai2 4 1 8 6 7 9 5 1 2 3.6

ai3 4 1 8 6 3 2 3 8 6 7

ai4 4 1 8 6 7 9 3 1 2 3.6

ci 0.1 0.2 0.2 0.4 0.4 0.6 0.3 0.7 0.5 0.5 Table F.1: Parameters of the Shekel’s modified foxhole functions.

• The function f21 is another class of two-dimension Shekel’s function that reads

f21(x)≡

 1 500+

X25

j=1

j+ (x1−a1j)6+ (x2−a2j)6−1

−1

, (F.19a)

xi∈[−65,+65], xi =−32, f21(x)≈1, (F.19b) where the various coefficients are defined in Tab.{F.2}

i 1 2 3 4 5 6 7 8 9 10

a1i −32 −16 0 16 32 −32 −16 0 16 32

a2i −32 −32 −32 −32 −32 −16 −16 −16 −16 −16

i 11 12 13 14 15 16 17 18 19 20

a1i −32 −16 0 16 32 −32 −16 0 16 32

a2i 0 0 0 0 0 16 16 16 16 16

i 21 22 23 24 25

a1i −32 −16 0 16 32

a2i 32 32 32 32 32

Table F.2: Parameters of the Shekel’s alternative foxhole function.

• The function f22 is defined as Kowalik’s function in four dimension [61] and reads f22(x)≡

X11

i=1

ai− x1(b2i +bix2) b2i +bix3+x4

2

, (F.20a)

xi∈[−5,+5], x = [0.1928(...),0.1908(...),0.1231(...),0.1358(...)], (F.20b)

f22(x) =0.0003075(...), (F.20c)

where the various coefficients are defined in Tab.{F.3}

i ai 1/bi

1 0.1957 0.25 2 0.1947 0.5 3 0.1735 1 4 0.1600 2 5 0.0844 4 6 0.0627 6 7 0.0456 8 8 0.0342 10 9 0.0323 12 10 0.0235 14 11 0.0246 16

Table F.3: Parameters of the Kowalik’s function.

F.2 Random surface generator

As explained in the main document, the computation of theoretical error bars using the bootstrap algorithm requires the construction of smooth random surfaces Rin the interval [−1,+1] that allows to compute variations of Vlowk within a given tolerance around an initial input, i.e. such that

∀i, j = 1. . . N , hR(ki, kj)i= 0, Var [R(ki, kj)] = 0. (F.21) We have devised a simple method to construct such functions in the case of a regular mesh Xi=X0+ (i−1)∆X.

F.2. Random surface generator 157

F.2.1 One-dimension case

The idea consists in computing at each bin a uniform random valueα in [0,1), then convoluting it with the values obtained for all neighbors using an effective range function. Thus we define

∀i= 1. . . N , α(Xi) =U(0,1), (F.22a)

β(Xi)≡ XN

j=1

α(Xj)f(Xi, Xj), (F.22b)

f(Xi, Xj)≡exp

"

Xi−Xj σ

2#

Θ(|Xi−Xj| −K), (F.22c)

γ(Xi)≡2

β(Xi) βmax(Xi)

−1, βmax(Xi)≡ XN

j=1

f(Xi, Xj), (F.22d) wheref is taken as a gaussian smoothing function. The former definition allows the random drawings at two separate bins to interact with each other. Theγ curve verifies then for each i

hγ(Xi)i=2

hβ(Xi)i βmax(Xi)

−1 = 2 βmax(Xi)

 XN

j=1

hα(Xj)if(Xi, Xj)

−1

= 2

βmax(Xi)

βmax(Xi)

2 −1 = 0. (F.23)

Finally, one renormalizesγ into a distribution of variance 1/4, such that in average the random variable

∀i= 1. . . N , R(Xi)≡ γ(Xi) 4p

Var [γ(Xi)], (F.24)

remains most of the time in the interval [−1,+1], using the property that a random variable almost never deviates over twice its standard deviation, by analogy with the normal distribution.

Finally, we evaluate

Var [γ(Xi)] =

2 βmax(Xi)

2

Var [β(Xi)]

=

2 βmax(Xi)

2

 XN

j=1

Var [α(Xj)] f2 (Xi, Xj)

= 1

max2 (Xi) XN

j=1

f2 (Xi, Xj), (F.25)

using the fact that the random variables α(Xi) and α(Xj) are decorrelated fori6=j, and Var [U(0,1)] = 1

12. (F.26)

Results are presented inFig. F.10 for σ= 0.1,K = 0.5 and a mesh of 50 points equally spaced in [0,2.6](1). We consider different cases, i.e.

1Obviously we have in mind the application of this method for realistic calculations where the mesh is defined in momentum space. These values forσandKcorrespond to a good compromise for practical applications with no brutal variations ofR.

1. one random drawing of α in [0,1),

2. distribution of α according to a step function,

3. distribution of α where all values except one are zero, 4. large number of random drawings.

While the first three situations probe different regimes of the algorithm, the last one allows to compute the distribution ofR(Xi) for each i.

Random

0.0 0.2 0.4 0.6 0.8 1.0

0 5 10 15 20

0.0 0.5 1.0 1.5 2.0 2.5

X

-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0

Step

0.0 0.5 1.0 1.5 2.0 2.5

X

Dirac

0.0 0.5 1.0 1.5 2.0 2.5

X

Multi

0.0 0.5 1.0 1.5 2.0 2.5

X

Figure F.10: Generation of random curves in one dimension for different cases pre- sented in the text. The green curve presents the value of βmax(Xi), while in the lower panels solid and dashed lines correspond to γ and R, respectively.

We find that using simple algorithm leads to a biaised definition of R, as shown inFig.F.11 on the distribution ofR(Xi) at different points. Indeed (i) the distribution ofR(XN/2) is of mean zero and variance one, but (ii) for i= 1 ori=N, it is of variance one but is not centered. This unwanted property corresponds to the fact thatβ is statistically more likely to reachβmax at the boundaries of the problem, where only one half of the mesh is fully weighted by the effective range functionf. A signature of such a problem is the non-constant value ofβmaxover the mesh.

The solution consists in considering extra points belowX1 and overXN, i.e. a mesh{X} which verifies

∀i= 1. . . N , Xi=Xi, ∀j , Xj+1 −Xj = ∆X, (F.27) such that βmax(Xi)≡βmax, as well as Var [γ(Xi)]≡Var [γ], are independent of Xi(2). One has then

∀i= 1. . . N , α(Xi) =U(0,1), (F.28a)

β(Xi)≡

+∞X

j=−∞

α(Xj)f(Xi, Xj), (F.28b) γ(Xi)≡2

β(Xi) βmax

−1, (F.28c)

2This justifies the use of the Θ function in the expression off, which definesKas the maximum range of the smoothing.

F.2. Random surface generator 159

-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 0.0

0.2 0.4 0.6 0.8 1.0

Y ie ld [ a r b . u .]

(XN/2) (XN) (X1)

R(XN/2) R(XN) R(X1)

Figure F.11: Distributions of γ(Xi) and R(Xi) at different positions.

R(Xi)≡ γ(Xi) 4p

Var [γ], (F.28d)

∀j0, βmax

+∞X

j=−∞

f(Xj0, Xj), (F.28e)

Var [γ] = 1 3βmax2

+∞X

j=−∞

f2 (Xj0, Xj), (F.28f) Results for this so-calledunbiased case are presented inFigs. (F.12,F.13). One sees immediately that (i) βmax is indeed independent ofX in the area of interest (between the blue lines), (ii) the distribution ofR is also independent ofX and corresponds at each point to a random variable of mean zero and variance one, i.e. Ris indeed a ”random curve” in [−1,+1] (in average).

Random

0.0 0.2 0.4 0.6 0.8 1.0

0 5 10 15 20

0.0 1.0 2.0 3.0

X

-1.0 -0.5 0.0 0.5 1.0

Step

0.0 1.0 2.0 3.0

X

Dirac

0.0 1.0 2.0 3.0

X

Multi

0.0 1.0 2.0 3.0

X

Figure F.12: Same as in Fig. F.10 in the unbiased case. Only values between the blue lines are actually considered in the end, other bins are only in intermediate steps of the generator.

-1.0 -0.5 0.0 0.5 1.0 0.0

0.2 0.4 0.6 0.8 1.0

Y ie ld [ a r b . u .]

(XN/2) (XN) (X1)

R(XN/2) R(XN) R(X1)

Figure F.13: Same as in Fig. F.11in the unbiased case.

F.2. Random surface generator 161

F.2.2 Two-dimension case

The generalization of the previous algorithm for the two-dimension case, after all biases are removed, reads then easily

∀i, j = 1. . . N , α(Xi, Xj) =U(0,1), (F.29a)

β(Xi, Xj)≡ X+∞

k=−∞

+∞X

ℓ=−∞

α(Xk, X)f(Xi, Xk)f(Xj, X), (F.29b) γ(Xi, Xj)≡2

β(Xi, Xj) βmax

−1, (F.29c)

R(Xi, Xj)≡γ(Xi, Xj) 4p

Var [γ], (F.29d)

∀k0, ℓ0, βmax≡ X+∞

k=−∞

+∞X

ℓ=−∞

f(Xk0, Xk)f(X0, X)

= X+∞

k=−∞

f(Xk0, Xk)

!2

, (F.29e)

Var [γ] = 1 3βmax2

X+∞

k=−∞

f2 (Xk0, Xk)

!2

. (F.29f)

Results are presented inFigs. (F.14,F.15) for equivalent cases as in the previous section(3). For large number of samplings one sees that the distribution of R(Xi, Xj) is also independent ofXi and Xj and corresponds at each point to a random variable of mean zero and variance one, i.e.

Ris indeed a ”random surface” in [−1,+1] (in average).

3The ”Dirac” case corresponds to all values are zero except in a small region.

Random

0.0 0.5 1.0 1.5 2.0 2.5

X'

0.0 0.2 0.4 0.6 0.8 1.0

0.0 0.5 1.0 1.5 2.0 2.5

X'

0 5 10 15 20 25 30 35 40

0.0 0.5 1.0 1.5 2.0 2.5

X

0.0 0.5 1.0 1.5 2.0 2.5

X'

R

-1.0 -0.5 0.0 0.5 1.0

Step

0.0 0.5 1.0 1.5 2.0 2.5

X'

0.0 0.2 0.4 0.6 0.8 1.0

0.0 0.5 1.0 1.5 2.0 2.5

X'

0 5 10 15 20 25 30 35 40

0.0 0.5 1.0 1.5 2.0 2.5

X

0.0 0.5 1.0 1.5 2.0 2.5

X'

R

-1.0 -0.5 0.0 0.5 1.0

Dirac

0.0 0.5 1.0 1.5 2.0 2.5

X'

0.0 0.2 0.4 0.6 0.8 1.0

0.0 0.5 1.0 1.5 2.0 2.5

X'

0 5 10 15 20 25 30 35 40

0.0 0.5 1.0 1.5 2.0 2.5

X

0.0 0.5 1.0 1.5 2.0 2.5

X'

R

-1.0 -0.5 0.0 0.5 1.0

Figure F.14: Generation of unbiased random curves in two dimensions for different cases presented in the text. from top to bottom are displayed surface plots of α,β and R.

-1.0 -0.5 0.0 0.5 1.0 0.0

0.2 0.4 0.6 0.8 1.0

Y ie ld [ a r b . u .]

(XN/2,XN/2) (X1,XN/2) (X1,X1) R(XN/2,XN/2) R(X1,XN/2) R(X1,X1)

Figure F.15: Distributions of γ(Xi) and R(Xi) at different positions.

163

Bibliography

[1] A. R. Edmonds: Angular Momentum in Quantum Mechanics (Princetown University Press, Princetown, NJ, 1957)

[2] D. A. Varshalovich, A. N. Moskalev and V. K. Khersonsky: Quantum Theory of Angular Momentum: Irreducible tensors, spherical harmonics, vector coupling coefficients, 3NJ Symbols (World Scientific, Singapore, 1988)

[3] M. Abramowitz and I. Stegun: Handbook of Mathematical Functions (Dover, New York, 1965)

[4] J. Winter: Tensor spherical harmonics. Lett. Math. Phys.6 (1982) 91–96

[5] A. L. Goodman: Self-consistent symmetries of the Hartree-Fock-Bogoliubov equations in a rotating frame. Nucl. Phys. A230 (1974) 466–476

[6] J. Dobaczewski, H. Flocard and J. Treiner: Hartree-Fock-Bogolyubov description of nuclei near the neutron-drip line. Nucl. Phys. A422 (1984) 103–139

[7] C. Bloch and A. Messiah: The canonical form of an antisymmetric tensor and its application to the theory of superconductivity. Nucl. Phys. 39(1962) 95–106

[8] B. Zumino: Normal Forms of Complex Matrices. J. Math. Phys. 3 (1962) 1055–1057 [9] J. Dobaczewski: Generalization of the Bloch-Messiah-Zumino theorem. Phys. Rev. C62

(2000) 017301. arXiv:math-ph/0002034

[10] J. Escher, B. K. Jennings and H. S. Sherif: Spectroscopic amplitudes and microscopic substructure effects in nucleon capture reactions. Phys. Rev. C64 (2001) 065801. arXiv:

nucl-th/0107011

[11] A. E. L. Dieperink and T. de Forest, Jr.: Center-of-mass effects in single-nucleon knock-out reactions. Phys. Rev. C 10(1974) 543–549

[12] B. K. Jennings: Low energy behavior of the 7Be(p,γ)8B reaction. Phys. Rev. C62(2002) 027602

[13] A. V. Shebeko, P. Papakonstantinou and E. Mavrommatis: The one-body and two-body density matrices of finite nuclei with an appropriate treatment of the center-of-mass motion.

Eur. Phys. J. A27 (2006) 143–155. arXiv:nucl-th/0602056

[14] D. Van Neck, A. E. L. Dieperink and M. Waroquier: Natural orbitals, overlap functions, and mean-field orbitals in an exactly solvable A-body system. Phys. Rev. C53(1996) 2231–2242 [15] D. Van Neck and M. Waroquier: Single-particle properties in self-bound systems. Phys. Rev.

C58(1998) 3359–3367

[16] C. F. Cl´ement: Theory of overlap functions (I). Single particle sum rules and centre-of-mass corrections. Nucl. Phys. A213(1973) 469–492

[17] C. F. Cl´ement: Theory of overlap functions (II). The overlap representation. Nucl. Phys.

A213 (1973) 493–509

[18] D. Van Neck, M. Waroquier, A. E. L. Dieperink, S. C. Pieper and V. R. Pandharipande:

Center-of-mass effects on the quasi-hole spectroscopic factors in the 16O(e,ep) reaction.

Phys. Rev. C57(1998) 2308–2315. arXiv:nucl-th/9804067