Neutron scattering length of lithium and boron and their isotopes

Abstract

Coherent neutron scattering lengths and free cross sections were measured in order to determine the spin dependent scattering lengths of the isotopes of Li and B. The transmission measurements on Li at neutron energies of 0.51 meV, 1.26 eV and 5.19 eV delivered data for the eLi-abundances in the samples and for the free scattering cross section of 7Li. By means of experiments on 15 different samples of lithium compounds we obtained the complex spin state scattering lengths for the bound atoms to be: A review on slow neutron scattering and resonance data shows an over all consistency of all values.

Combiningab initiocalculations and low-energy effective field theory for halo nuclear systems: The case of7Li+n→8Li+γ

“…to scale as 1/(M n γ) [39][40][41][42][43]. In contrast, the natural scaling 1/(M n Λ) would lead to a scattering length similar to that observed in the 3 S 1 channel of 7 Lin scattering, a ( 3 S1) = 0.87(7) fm [61]. (See Table II for a list of S-wave scattering lengths and P -wave effective ranges, and their scaling assignments.…”

“…Instead, we reproduce the unnaturally large scattering length in the 5 S 2 channel, a ( 5 S2) = −3.63(5) fm [61], by taking the corresponding S-wave coupling g ( 5 S2) to be unnaturally enhanced, i.e. to scale as 1/(M n γ) [39][40][41][42][43].…”

Electromagnetic strength of neutron and proton single-particle halo nuclei

“…For the 7 Be+p system s-wave scattering lengths a S for channel spin S=2 and S=1 (from coupling the spins of the proton and 7 Be) have been determined experimentally, however with large uncertainties [75]. More precise values are available for the mirror system 7 Li+n [76]. The scattering lengths are easily reproduced in the single-particle model by adjusting the depth of the Woods-Saxon potential in the continuum.…”

Low-energy cross section of theBe7(p,γ)Schümann1, Typel2, Hammache3 et al. 2006Phys. Rev. C595310View full textAdd to dashboardCite

“…As usual, the p-wave potential depth has been adjusted to match the 8 B proton binding energy, this yields a depth of 43.183 MeV. The s-, d-and f-wave potentials have been adjusted to reproduce the s-wave scattering lengths of the mirror 7 Li+n reaction [20], this yields V 1 = 43.857 MeV for channel spin S=1 and V 2 = 52.597 MeV for channel spin S=2. We note that we obtain for the dominant channel spin S=2 an s-wave scattering length for 7 Be+p of a theo 02 = −8 fm which agrees well with the recently measured value of a exp 02 = −7 ± 3 fm (Angulo et al [21]).…”