Determination of the Neutron-Neutron Scattering Length from the ReactionT(d, He3)2n

Shell Model in the Continuum—Application to the Four-Nucleon System

“…Feshbach's theory combined with the concepts of the shell model has been applied to the study of elastic scattering of neutrons from N 15 by Lemmer and Shakin 2 and to the scattering of neutrons from C 12 by Lovas. 3 The possibility of extending the shell model or independent-particle model to the treatment of continuum problems has stimulated many authors, and several other formal theories have been put forth.…”

“…T HE n-n interaction at low energies has been extensively studied through reactions such as T>(n,p)2n, 1 z E.(n,d)2n, 2 and T(^, 3 He)2^, 3 and through a different approach by the reaction w~T> -» 2^7, 4 where in the final state only the two neutrons are strongly interacting. The theory for the analysis of the data obtained in these experiments is well enough known 3 * 5-7 that it is not discussed here.…”

“…8) were derived from analyzing experimental data. A directinteraction approximation analogous to Eq (3,2). is used for |^X (+) >-…”

Erratum: Do excited states exist in a system of two neutrons? [JETP Lett. 67, No. 11, 903–909 (10 June 1998)]

“…We note that in these investigations emphasis has been placed on confirmation of the hypothesis of charge independence and symmetry of the nuclear forces and not on a search for excited states of unstable 2 n. As a rule, the spectra have been obtained in a narrow energy range near zero binding energy of the dineutron. 2 On the other hand, in high-energy physics the searches have been conducted for ''narrow'' dibaryonic resonances ( 2 p) with energies of tens and even hundreds of MeV, which are traditionally far from the excitation energies characteristic for low-energy nuclear physics. 3 The objective of the present work was to search for excited states of the dineutron in the reaction T͑d, 3 He) by the conventional methods of nuclear spectroscopy in the interval from the 2 n ground state up to the maximum possible energies admissible under the experimental conditions (E*ϳ15 MeV).…”

Two-proton final-state interactions in the reactions ³He (d,t)2p, d(³He, t)2p, ³He(³He, 4He)2p, and p(³He, d)2p

“…Calculations using more realistic potentials have been made recently by Koehler and Mann (1964) and by Koehler (1965). Recently Henley, Richards, and Yu ( 1965) using various Born approximations found it necessary to include final-state interaction effects to explain the data of (Baumgartner et al, 1966) the He spectra at laboratory angles 3 3 of 6° and 8° .from the reaction t(d, He)2n were analyzed us'ing the final-state interaction theory of Watson ( 1952) and Migdal ( 1955) and gave a value of a = -16. l ± l. 0 F. The application of the simple n Watson-Migdal theory was justified by the analysis of the triton spectrum at a laboratory angle of 8 ° from the reaction 3 He(d, t)2p…”