ИСТИНА

Vertex constants (VCs) and asymptotic normalization coefficients (ANCs), which are proportional to VCs, are important nuclear characteristics. They determine cross sections of radiative capture processes at astrophysical energies. Their knowledge is necessary for solving the inverse scattering problem. The 6Li nucleus in the α+d channel is one of the most interesting systems for which it is important to know VCs and ANCs. The ANC values for this system determine the cross section of the radiative capture 4He(d,γ) 6Li, which is the only process of 6Li formation in the Big Bang model. In the previous paper [1], the authors used data from various dα phase-shift analyses within both one- and two-channel versions of the effective range expansion [2] for the analytic continuation to the pole of a bound state of 6Li. The VCs Gl and ANCs Cl for the channels with orbital angular momenta l = 0 and l = 2 were found. Inelasticity effects were not included in the formalism. However, due to the small binding energy of the deuteron, the three-body inelastic channel corresponding to the deuteron breakup opens at rather low energies. Above the inelastic threshold, the phase shifts and mixing coefficient acquire imaginary parts which increase with increasing energy. In the present study, we compared two methods of treating inelasticity: 1) just ignoring the aforementioned imaginary parts and 2) employing the parameterization of Arndt and Roper [3]. For each method, using two-channel versions of the effective range expansion and data of the phase analysis [4], the VCs and ANCs for 6Li were determined. Neglecting the inelasticity (method 1) results in G02 = 0.3740 fm, G22 = 3.64 10-4 fm, C0 = 1.958 fm-1/2 , and C2 = 0.091 fm-1/2. For the parameterization [3] (method 2) one gets G02 = 0.344 fm, G22 = 2.14 10-4 fm, C0 = 1.877 fm-1/2, and C2 = 0.070 fm-1/2. The difference between the results of two methods is small but not negligible. Note that the difference arises not only for the channel l = 2 where the inelasticity coefficient η in the energy range considered reaches 0.6 but for the channel l = 0 as well where η is close to unity (η ≈ 0.9). This effect is the result of the channel mixing. 1. L.D. Blokhintsev, D.A. Savin// Few-Body Syst. 2013. DOI 10.1007/s00601-012-0544. 2. L.D.Blokhintsev // Phys. At. Nucl. 2011. V.74. P. 979; Bull. Russ. Acad. Sci. Physics. 2012. V.76. P. 425. 3. R.R. Arndt, L.D. Roper// Phys. Rev. D. 1982. V.24. P.7, 25. 4. W.Grüebler et al. // Nucl. Phys. A. 1975. V.242. P.245.