Toward the Application of Three-Dimensional Approach to Few-body Atomic Bound States M. R. Hadizadeha and L. Tomiob Instituto de Fı́sica Teórica (IFT), Universidade Estadual Paulista (UNESP), Barra Funda, 01140-070, São Paulo, Brazil. Abstract. The first step toward the application of an effective non partial wave (PW) numerical approach to few-body atomic bound states has been taken. The two-body transition amplitude which appears in the kernel of three-dimensional Faddeev-Yakubovsky integral equations is calculated as function of two-body Jacobi momen- tum vectors, i.e. as a function of the magnitude of initial and final momentum vectors and the angle between them. For numerical calculation the realistic interatomic interactions HFDHE2, HFD-B, LM2M2 and TTY are used. The angular and momentum dependence of the fully off-shell transition amplitude is studied at negative energies. It has been numerically shown that, similar to the nuclear case, the transition amplitude exhibits a characteristic angular behavior in the vicinity of 4He dimer pole. Introduction In recent years the 4He trimer and tetramer have been the center of several theoretical investigations (see, for exam- ple, Refs. [1–3] and references therein). From all employed methods in these studies, the Faddeev-Yakubovsky (FY) schemas are perhaps most attractive since they reduces the Schrödinger equation for three (four) particle systems into a coupled set (two coupled sets) of integral or differen- tial equations which can be used to study the bound and scattering states in a rigorous way. The differential form of FY equations has been successfully applied in nuclear bound states calculations, but there are limitations in its application to atomic systems. The limitation arises from eccentricities of the interatomic interactions, since inter- atomic interactions often contain very strong short range repulsion which leads to tedious and cumbersome numer- ical procedure. In calculations of atomic systems, because of the short range correlations, one needs a large num- ber of PWs to obtain the converged results. To overcome this problem few numerical techniques are developed, the tensor-trick method [4,5], representation of Faddeev equa- tions in Cartesian coordinate [6], the operator form of Fad- deev equations in total angular momentum representation [7] and also a hybrid method [8]. The three and four-body atomic bound states have been also studied with short-range forces and large scattering length at leading order in an Ef- fective field theory approach [9]-[11], but these investiga- tions are also based on PW decomposition and the interac- tions are restricted to only s-wave sector. By these considerations we are going to extend a nu- merical method, which has been successfully applied to nuclear bound and scattering systems and avoids the PW representation and its complexity, to atomic bound states. a e-mail: hadizade@ift.unesp.br b e-mail: tomio@ift.unesp.br It should be clear that the building blocks to the few-body calculations without angularmomentumdecomposition are two-body off-shell transition amplitudes, which depend on the magnitudes of the initial and final Jacobi momenta and the angle between them. Elster et al. have calculated the NN transition amplitude for spinless particles in a non PW representation by using the Malfliet-Tjon type potentials [12]. Our aim in this paper is to calculate the matrix ele- ments of the fully off-shell two-body transition amplitude at negative energies for realistic interatomic interactions, we study the momentum and angle dependence of transi- tion amplitudes. This paper is organized as follows. In sec- tion 1 we represent the explicit form of studied interatomic interactions in configuration andmomentum spaces. In sec- tions 2 and 3 we present our numerical results for homoge- nous and inhomogenous Lippmann-Schwinger equations in a non PW representation. An outlook is provided in sec- tion 4. 1 4He-4He Interatomic Interactions In this study as 4He-4He interatomic interactions we use the realistic HFDHE2 [13], HFD-B [14], LM2M2 [15] and TTY [16] potentials. The semi-empirical HFDHE2, HFD- B and LM2M2 potentials, which are constructed by Aziz and collaborators, have the general form V(r) = ε ( Va(x) + Vb(x) ) , (1) where x = r rm , r and rm are expressed in the unit Å. The terms Va(x) and Vb(x) read Va(x) = ⎧⎪⎪⎨⎪⎪⎩ Aa ( sin [2π(x − x1) x2 − x1 − π 2 ] + 1 ) , x1 ≤ x ≤ x2 0, x � [x1, x2] . (2) EPJ Web of Conferences , 02010 (2010) DOI:10.1051/epjconf/2010��02010 © Owned by the authors, published by EDP Sciences, 2010 This is an Open Access article distributed under the terms of the Creative Commons Attribution-Noncommercial License 3.0,�which permits unrestricted use, distribution, and reproduction in any noncommercial medium, provided the original work is properly cited� Article available at http://www.epj-conferences.org or http://dx.doi.org/10.1051/epjconf/20100302010 http://www.epj-conferences.org http://dx.doi.org/10.1051/epjconf/20100302010 EPJ Web of Conferences The interatomic 4He-4He potentials as a function of the distance r between the atoms. The region around minima of the potentials is shown in the inset of the figure. Vb(x) = A e(−αx+βx 2)− ( C6 x6 + C8 x8 + C10 x10 ) F(x) , (3) and the function F(x) is given by F(x) = ⎧⎪⎪⎨⎪⎪⎩ e−( Dx −1) 2 , x ≤ D 1, x > D. (4) The parameters of the HFDHE2, HFD-B and LM2M2 po- tentials are given in Table 1. The explicit form of the theo- retical TTY potential is V(r) = A ( Vex(r) + Vdisp(r) ) , (5) where r stands for the distance between the 4He atoms given in atomic length units. The function Vex(r) has the form Vex(r) = D rp e(−2βr), (6) with p = 7 2β − 1 . The function Vdisp(r) reads Vdisp(r) = − N∑ n=3 C2n f2n(r) r−2n, (7) the coefficients C2n are calculated via the recurrency rela- tion C2n = ( C2n−2 C2n−4 )3 C2n−6, (8) and the functions f2n(r) are given by f2n(r) = 1 − e ( −b(r) r ) 2n∑ k=0 ( b(r) r )k k! , (9) where b(r) = 2β − [ 7 2β − 1 ] 1 r . (10) The parameters of the TTY potential are given in Table 2. In Figure (1) all potentials are plotted as function of dis- tance between the 4He atoms. Moreover, in the inset to this figure the region around the minima of the potentials is shown for providing a better comparison. In order to be able to implement the introduced inter- atomic interactions in few-body atomic bound and scat- tering state calculations in momentum space, we need to transform these potentials to momentum space. The matrix elements of the potentials can be obtained by following re- lation V( , ′) ≡ V(p, p′, xpp′ ) = 1 2π2q ∫ ∞ 0 dr r sin(qr)V(r) ; q = | − ′| � 0 = 1 2π2 ∫ ∞ 0 dr r2 V(r) ; q = 0 (11) where p and p′ are magnitudes of initial and final two-body Jacobi momentum vectors, xpp′ is the angle between them 02010-p.2 19th International IUPAP Conference on Few-Body Problems in Physics 0 5 10 15 20 0 5 10 15 20 0 2000 4000 6000 8000 p [A−1]p’ [A−1] V( p, p’ ,x =− 1) [ K .A 3 ] 0 5 10 15 20 0 5 10 15 20 0 2000 4000 6000 8000 p [A−1]p’ [A−1] V( p, p’ ,x =0 ) [K .A 3 ] 0 5 10 15 20 0 5 10 15 20 0 2000 4000 6000 8000 p [A−1]p’ [A−1] V( p, p’ ,x =+ 1) [ K .A 3 ] HFDHE2 HFDHE2 HFDHE2 0 5 10 15 20 0 5 10 15 20 0 1000 2000 3000 4000 p [A−1]p’ [A−1] V( p, p’ ,x =− 1) [ K .A 3 ] 0 5 10 15 20 0 5 10 15 20 0 1000 2000 3000 4000 p [A−1]p’ [A−1] V( p, p’ ,x =0 ) [K .A 3 ] 0 5 10 15 20 0 5 10 15 20 0 1000 2000 3000 4000 p [A−1]p’ [A−1] V( p, p’ ,x =+ 1) [ K .A 3 ] HFD-B HFD-B HFD-B 0 5 10 15 20 0 5 10 15 20 0 1000 2000 3000 4000 p [A−1]p’ [A−1] V( p, p’ ,x =− 1) [ K .A 3 ] 0 5 10 15 20 0 5 10 15 20 0 1000 2000 3000 4000 p [A−1]p’ [A−1] V( p, p’ ,x =0 ) [K .A 3 ] 0 5 10 15 20 0 5 10 15 20 0 1000 2000 3000 4000 p [A−1] p’ [A−1] V( p, p’ ,x =+ 1) [ K .A 3 ] LM2M2 LM2M2 LM2M2 0 5 10 15 20 0 5 10 15 20 −200 0 200 400 600 800 p [A−1]p’ [A−1] V( p, p’ ,x =− 1) [ K .A 3 ] 0 5 10 15 20 0 5 10 15 20 −200 0 200 400 600 800 p [A−1]p’ [A−1] V( p, p’ ,x =0 ) [K .A 3 ] 0 5 10 15 20 0 5 10 15 20 −200 0 200 400 600 800 p [A−1] p’ [A−1] V( p, p’ ,x =+ 1) [ K .A 3 ] TTY TTY TTY Momentum-space representation of interatomic 4He-4He potentials V(p, p′, xpp′ ) in fixed angles xpp′ = 0,±1. and q = (p2 + p′2 − 2pp′xpp′ ) 12 is the difference between them. Clearly the knowledge of the structure and range of potentials is important in the calculation of two-body tran- sition amplitudes, which appear in the kernel of the integral equations of two-, three- and four-body bound and scatter- ing calculations. In Figure (2) the momentum dependence of the potentials are shown at fixed angles xpp′ = 0,±1. As shown all potentials have similar behavior. The ridge around p = p′ arises from strong repulsive core. The be- havior of the potentials at forward angle, i.e. xpp′ = +1, is different from other angles, and according to Eq. (11) the value of the potentials in this angle is fixed for p = p′. Note that the potentials vanish at enough large values of Jacobi momenta. i.e. pmax = 20Å−1. We should mention that for calculation of matrix elements of potential, Eq. (11), the cutoff value of rmax = 30Å and 200 mesh points have been used. 02010-p.3 EPJ Web of Conferences The parameters of the 4He−4He interactions which are constructed by Aziz and collaborators. Parameter HFDHE2 HFD-B LM2M2 ε [K] 10.8 10.948 10.97 rm [Å] 2.9673 2.963 2.9695 A 544850.4 184431.01 189635.353 α 13.353384 10.43329537 10.70203539 β 0 −2.27965105 -1.90740649 C6 1.3732412 1.36745214 1.34687065 C8 0.4253785 0.42123807 0.41308398 C10 0.178100 0.17473318 0.17060159 D 1.241314 1.4826 1.4088 Aa − − 0.0026 x1 − − 1.003535949 x2 − − 1.454790369 The parameters of the 4He−4He TTY potential. A [K] 315766.2067 β [ (a.u.)−1 ] 1.3443 D 7.449 N 12 C6 1.461 C8 14.11 C10 183.5 2 4He Dimer The 4He dimer can be described by homogeneousLippmann- Schwinger integral equation: ψd( ) = 1 Ed − p2 m ∫ d3p′ V( , ′)ψd( ′). (12) This integral equation can be solved numerically by direct or iterative methods. We have solved this integral equation by direct method and the numerical results for dimer bind- ing energy by using the introduced interatomic interactions are given in Table (3) in comparison to corresponding PW and experimental results. In our numerical calculations the 4He atom mass is defined by �2m = 12.12KÅ 2. For dis- cretization of the continuous momentum and angle vari- ables we have used the quadrature Gauss-Legendre by us- ing linear mapping for all variables. The number of mesh grids for Jacobi momenta and angle variable are 200 and 150 correspondingly. The calculated dimer binding energy in unit of mK for realistic interatomic potentials in comparison to corresponding PW and experimental data. HFDHE2 HFD-B LM2M2 TTY PW [17] -0.83012 -1.68541 -1.30348 -1.30962 Presnet -0.83011 -1.68540 -1.30347 -1.30962 EXP. [18] -1.1+0.3−0.2 3 Two-Body Transition Amplitude The building blocks for few-body bound and scatter- ing state calculations are two-body transition amplitudes T which follow the inhomogenous Lippmann-Schwinger equation T = V + VG0T, (13) where V is the two-body, e.g. two-atom, potential andG0 = (E − H0)−1 is free two-body propagator. For momentum space calculations one needs the matrix elements of transi- tion amplitude in desired energy E which can be obtained by representation of Eq. (13) in two-body basis states [12] T ( ′, ; E) = V( ′, ) + ∫ d3p′′ V( ′, ′′) E − p′′2 m T ( ′′, ; E). (14) In order to solve this three-dimensional integral equa- tion directly without employing PW projection, we have to define a suitable coordinate system. To this aim we choose vector parallel to z−axis and vector ′ in the x − z plane and express the integration vector ′′ with respect to them. By this considerations Eq. (14) can be written explicitly as T (p′, p, xp p′ ; E) = V(p′, p, xp p′ ) + ∫ ∞ 0 dp′′p′′2 ∫ 1 −1 dxp p′′ ∫ 2π 0 dϕ′′ 1 E − p′′2 m V(p′, p′′, xp′ p′′ ) × T (p′′, p, xp p′′ ; E), (15) where xp p′ = · ′, xp p′′ = · ′′, xp′ p′′ = ′ · ′′ = xp p′ xp p′′ + √ 1 − x2p p′ √ 1 − x2p p′′ cosϕ′′. (16) The ϕ′′ integration acts only on V(p′, p′′, xp′ p′′ ), so this integration can be carried out separately as v(p′, p′′, xp p′ , xp p′′ ) ≡ ∫ 2π 0 dϕ′′V(p′, p′′, xp′ p′′ ), (17) and consequently the integral equation (15) can be written as T (p′, p, xp p′ ; E) = 1 2π v(p′, p, xp p′ , 1) + ∫ ∞ 0 dp′′p′′2 ∫ 1 −1 dxp p′′ v(p′, p′′, xp p′ , xp p′′ ) E − p′′2 m ×T (p′′, p, xp p′′ ; E). (18) For a specific value of the off-shell momentum p and energy E and after discretization of continuousmomentum and angle variables, this two-dimensional integral equation can be turned into a system of linear equations as AT = B, 02010-p.4 19th International IUPAP Conference on Few-Body Problems in Physics where A and B are composed of kernel of integral equation and potential matrix elements respectively. For our numer- ical calculations we use the Lapack Fortran library [19] to solve the obtained system of linear equations. Certainly for few-atomic scattering state studies one needs to cal- culate the transition amplitude at positive energies which leads to a singularity in free propagator. This Cauchy sin- gularity can be splitted easily into a principal-value inte- gral and a δ-function imaginary part. Since we are going to use the recently developed formalism for three- and four- body bound states [20]-[23] for 4He trimer and tetramer calculations we study the behavior of transition amplitude at negative energies. To this aim we have solved the two- dimensional integral equation (18) by using 40 and 41mesh grids for Jacobi momenta and spherical angles variables re- spectively. We would like to mention that by considering the symmetry property of the angle argument xp′ p′′ , the polar angle integration in Eq. (17) can be done on inter- val [0, π2 ] by using 10 mesh grids. Our numerical results for fully offshell transition amplitudes T (p, p′, xpp′ ; E) are shown in Figure (3) at energy E = −100mK, which is close to 4He trimer binding energy, in fixed angles xpp′ = 0,±1. In Figure (4) we have shown the momentum and angular dependence of half offshell transition amplitude T (p, p0 = √ m|E|, x; E) at energy E = −100mK. As shown in Ref. [12] the bound states of two-body system lead to poles in the transition amplitude and the an- gular dependence of transition amplitude exhibits a very characteristic behavior in the vicinity of the bound state poles, which is given by the Legendre function correspond- ing to angular quantum number of the bound state T ( ′, ; E) E→Eb−→ 2l + 1 4π Pl(xpp′ ) gl(p′) gl(p) E − Eb , (19) where gl(p) = ∫ ∞ 0 dp′p′2 vl(p, p′)ψl(p′), (20) where vl(p, p′) and ψl(p′) are partial wave components of potential and tw-body wave function. To investigate this characteristic behavior in atomic case we have shown in Figure (5) the angular dependence of transition amplitude T (p0, p0, x; E) at the energy range −400 ≤ E ≤ −1mK. Clearly we can see by decreasing the magnitude of energy the angular behavior of transition amplitude is correspond- ing to the zeroth Legendre polynomial, i.e. P0(xpp′ ). For a better representation of this angular behavior we have shown in Figure (6) the transition amplitude just for few energies close to dimer s−wave pole and also the magni- tudes of transition amplitude at energy E = −1mK are listed in Table (4). 4 Outlook The first step toward the application of an established non partial wave approach to few-body atomic bound states has The matrix elements of T (p0, p0, xpp′ ; E) in unit of K.Å3 with p0 = √ m|E| at energy E = −1mK, which is close to s−wave 4He dimer pole. xpp′ = p̂. p̂′ HFDHE2 HFD-B LM2M2 TTY -1.00000 -2.5353 -3.0891 -3.0473 -4.8667 -0.99832 -2.5353 -3.0892 -3.0473 -4.8667 -0.99117 -2.5353 -3.0892 -3.0473 -4.8668 -0.97834 -2.5353 -3.0892 -3.0473 -4.8668 -0.95991 -2.5354 -3.0893 -3.0474 -4.8669 -0.93598 -2.5355 -3.0894 -3.0475 -4.8670 -0.90669 -2.5356 -3.0895 -3.0476 -4.8671 -0.87220 -2.5357 -3.0896 -3.0477 -4.8672 -0.83272 -2.5359 -3.0898 -3.0479 -4.8674 -0.78847 -2.5360 -3.0899 -3.0480 -4.8676 -0.73970 -2.5362 -3.0901 -3.0482 -4.8677 -0.68670 -2.5364 -3.0903 -3.0484 -4.8679 -0.62977 -2.5366 -3.0905 -3.0486 -4.8682 -0.56922 -2.5368 -3.0907 -3.0488 -4.8684 -0.50542 -2.5370 -3.0909 -3.0491 -4.8686 -0.43872 -2.5373 -3.0912 -3.0493 -4.8689 -0.36950 -2.5375 -3.0914 -3.0495 -4.8692 -0.29818 -2.5378 -3.0917 -3.0498 -4.8694 -0.22514 -2.5380 -3.0920 -3.0501 -4.8697 -0.15081 -2.5383 -3.0922 -3.0503 -4.8700 -0.07562 -2.5386 -3.0925 -3.0506 -4.8703 2.47E-32 -2.5388 -3.0928 -3.0509 -4.8706 +0.07562 -2.5391 -3.0931 -3.0512 -4.8709 +0.15081 -2.5394 -3.0933 -3.0514 -4.8711 +0.22514 -2.5397 -3.0936 -3.0517 -4.8714 +0.29818 -2.5399 -3.0939 -3.0520 -4.8717 +0.36950 -2.5402 -3.0941 -3.0522 -4.8720 +0.43872 -2.5404 -3.0944 -3.0525 -4.8723 +0.50542 -2.5407 -3.0946 -3.0527 -4.8725 +0.56922 -2.5409 -3.0949 -3.0530 -4.8728 +0.62977 -2.5411 -3.0951 -3.0532 -4.8730 +0.68670 -2.5413 -3.0953 -3.0534 -4.8732 +0.73970 -2.5415 -3.0955 -3.0536 -4.8734 +0.78847 -2.5417 -3.0957 -3.0538 -4.8736 +0.83272 -2.5418 -3.0958 -3.0539 -4.8738 +0.87220 -2.5420 -3.0960 -3.0541 -4.8739 +0.90669 -2.5421 -3.0961 -3.0542 -4.8740 +0.93598 -2.5422 -3.0962 -3.0543 -4.8742 +0.95991 -2.5423 -3.0963 -3.0544 -4.8743 +0.97834 -2.5424 -3.0963 -3.0544 -4.8743 +0.99117 -2.5424 -3.0964 -3.0545 -4.8744 +0.99832 -2.5424 -3.0964 -3.0545 -4.8744 +1.00000 -2.5424 -3.0964 -3.0545 -4.8744 been taken. The necessity of using this non partial wave ap- proach comes from this fact that in few-body atomic cal- culations one needs a large number of partial wave com- ponents, which is caused by very strong short range re- pulsion of interatomic interactions, to reach proper con- verged results. Instead of using standard partial wave rep- resentation which leads to tedious and cumbersome numer- ical procedure we intend to extend a non partial wave ap- proach which has been successfully applied to few-body nuclear systems. In the first step toward this goal the ma- trix elements of transition amplitudes which appear explic- itly in the few-body calculations have been calculated di- 02010-p.5 EPJ Web of Conferences 0 1 2 3 4 5 0 2 4 6 −10 −5 0 5 10 p [A−1]p’ [A−1] T( p, p’ ,x =− 1) [ K .A 3 ] 0 1 2 3 4 5 0 2 4 6 −10 −5 0 5 10 p [A−1]p’ [A−1] T( p, p’ ,x =0 ) [K .A 3 ] 0 1 2 3 4 5 0 2 4 6 −50 0 50 100 150 200 p [A−1] p’ [A−1] T( p, p’ ,x =+ 1) [ K .A 3 ] HFDHE2 HFDHE2 HFDHE2 0 1 2 3 4 5 0 2 4 6 −15 −10 −5 0 5 10 p [A−1] p’ [A−1] T( p, p’ ,x =− 1) [ K .A 3 ] 0 1 2 3 4 5 0 2 4 6 −15 −10 −5 0 5 10 p [A−1]p’ [A−1] T( p, p’ ,x =0 ) [K .A 3 ] 0 1 2 3 4 5 0 2 4 6 −50 0 50 100 150 p [A−1]p’ [A−1] T( p, p’ ,x =+ 1) [ K .A 3 ] HFD-B HFD-B HFD-B 0 1 2 3 4 5 0 2 4 6 −10 −5 0 5 10 p [A−1]p’ [A−1] T( p, p’ ,x =− 1) [ K .A 3 ] 0 1 2 3 4 5 0 2 4 6 −10 −5 0 5 10 p [A−1]p’ [A−1] T( p, p’ ,x =0 ) [K .A 3 ] 0 1 2 3 4 5 0 2 4 6 −50 0 50 100 150 p [A−1]p’ [A−1] T( p, p’ ,x =+ 1) [ K .A 3 ] LM2M2 LM2M2 LM2M2 0 1 2 3 4 5 0 2 4 6 −15 −10 −5 0 5 10 p [A−1]p’ [A−1] T( p, p’ ,x =− 1) [ K .A 3 ] 0 1 2 3 4 5 0 2 4 6 −15 −10 −5 0 5 10 p [A−1]p’ [A−1] T( p, p’ ,x =0 ) [K .A 3 ] 0 1 2 3 4 5 0 2 4 6 −50 0 50 100 150 p [A−1] p’ [A−1] T( p, p’ ,x =+ 1) [ K .A 3 ] TTY TTY TTY Momentum dependence of the fully offshell transition amplitude T (p, p′, xpp′ ; E) at E = −100mK in fixed angles xpp′ = 0,±1. rectly as function of two-body Jacobi momentum vectors. The calculated matrix elements can be entered in kernel of three-dimensional Faddeev-Yakubovsky integral equations to study the 4He trimer and tetramer ground and exited states. The numerical calculations for these bound states are currently underway. Acknowledgments Wewould like to thank the Brazilian agencies FAPESP and CNPq for partial support. References 1. E. Nielsen, D. V. Fedorov, and A. S. Jensen, J. Phys. , 4085 (1998). 2. V. Roudnev and S. L. Yakovlev, Chem. Phys. Lett. , 97 (2000). 3. E. A. Kolganova, A. K. Motovilov, S. A. Sofianos, J. Phys. , 1279 (1998). 4. N. W. Schellingerhout, L. P. Kok, and G. D. Bosveld, Phys. Rev. , 5568 (1989). 5. L. P. Kok, N. W. Schellingerhout, Few-Body Syst. , 99 (1991). 02010-p.6 19th International IUPAP Conference on Few-Body Problems in Physics 0 1 2 3 4 5 −1 −0.5 0 0.5 1 −10 −5 0 5 10 p [A−1] x T( p, p 0,x ) [K .A 3 ] 0 1 2 3 4 5 −1 −0.5 0 0.5 1 −10 −5 0 5 10 p [A−1] x T( p, p 0,x ) [K .A 3 ] HFDHE2 HFD-B 0 1 2 3 4 5 −1 −0.5 0 0.5 1 −10 −5 0 5 10 p [A−1]x T( p, p 0,x ) [K .A 3 ] 0 1 2 3 4 5 −1 −0.5 0 0.5 1 −10 −5 0 5 10 p [A−1] x T( p, p 0,x ) [K .A 3 ] LM2M2 TTY Momentum and angle dependences of T (p, p0, xpp′ ) with p0 = √ m|E| at E = −100mK. −0.4 −0.3 −0.2 −0.1 0 −1 −0.5 0 0.5 1 −3 −2.5 −2 −1.5 −1 −0.5 0 xE [K] T( p 0,p 0,x ;E ) [K .A 3 ] −0.4 −0.3 −0.2 −0.1 0 −1 −0.5 0 0.5 1 −4 −3 −2 −1 0 x E [K] T( p 0,p 0,x ;E ) [K .A 3 ] HFDHE2 HFD-B −0.4 −0.3 −0.2 −0.1 0 −1 −0.5 0 0.5 1 −4 −3 −2 −1 0 xE [K] T( p 0,p 0,x ;E ) [K .A 3 ] −0.4 −0.3 −0.2 −0.1 0 −1 −0.5 0 0.5 1 −5 −4 −3 −2 −1 0 x E [K] T( p 0,p 0,x ;E ) [K .A 3 ] LM2M2 TTY Angular dependence of T (p0, p0, xpp′ ; E) with p0 = √ m|E| as function of the energy from E = −1mK to E = −400mK. 6. J. Carbonell, C. Gignoux, and S. P. Merkuriev, Few- Body Syst. , 15 (1993). 7. V. V. Kostrykin, A. A. Kvitsinsky, and S. P. Merkuriev, Few-Body Syst. , 97 (1989). 02010-p.7 EPJ Web of Conferences −1 −0.5 0 0.5 1 −2.6 −2.4 −2.2 −2 −1.8 −1.6 −1.4 −1.2 −1 −0.8 −0.6 x T( p 0,p 0,x ) [ K .A 3 ] E=−0.001 K E=−0.03 K E=−0.07 K E=−0.12 K E=−0.2 K −1 −0.5 0 0.5 1 −3.5 −3 −2.5 −2 −1.5 −1 x T( p 0,p 0,x ) [ K .A 3 ] E=−0.001 K E=−0.03 K E=−0.07 K E=−0.12 K E=−0.2 K HFDHE2 HFD-B −1 −0.5 0 0.5 1 −3.5 −3 −2.5 −2 −1.5 −1 x T( p 0,p 0,x ) [ K .A 3 ] E=−0.001 K E=−0.03 K E=−0.07 K E=−0.12 K E=−0.2 K −1 −0.5 0 0.5 1 −5.5 −5 −4.5 −4 −3.5 −3 −2.5 −2 −1.5 x T( p 0,p 0,x ) [ K .A 3 ] E=−0.001 K E=−0.03 K E=−0.07 K E=−0.12 K E=−0.2 K LM2M2 TTY Angular dependence of T (p0, p0, xpp′ ; E) with p0 = √ m|E| at energies around 4He dimer s-wave pole. 8. V. A. Roudnev, S. L. Yakovlev, and S. A. Sofianos, Few-Body Syst. , 179 (2005). 9. L. Platter, H.W. Hammer, Ulf-G. Meissner, Phys. Rev. , 052101 (2004). 10. L. 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