Measurement of the Neutron-NeutronS-Wave Scattering Length from the Reactionπ−+d→2n+γ

Abstract

PHYSICAL REVIEW LETTERS 1 MARCH 1965 transition. This indicates double excitation through the 3~ state. All that can be said of the 2~ member of the K = 2 band is that it is weakly excited and does not show any regular oscillations. Similar behavior of single and double excitation is reported in Coulomb excitation of rotational bands in U 238 (see Fig. 3). 5 Two higher positive-parity K = 0 bands have been suggested. 1 Since no members of these bands have enhanced excitation, it is not likely that these bands are based on a single-phonon quadrupole vibration. Further evidence of this is that the 0 + level at 6.71 MeV and the 2 + level at 7.46 MeV both appear to be excited by double excitation of comparable strength.We wish to thank Professor John Blair and Mr. Pierre Darriulat for their helpful discussions.tWork done under the auspices of the U. S. Atomic Energy Commission.

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

“…: ~~ F was found, which agrees with the results of low energy scattering of free protons (Hulthe"n and Sagawara, 1957). The value of a from this experiment agrees n with the recent experimental results from the 1T capture by deuterium by Haddock et al (1965), where a value of a = -16.4 ~ ------n l. 3 F was found. The value of a from both of these experiments n is in agreement with the theoretical prediction of Heller, Signell, and Yoder (1964) based on the charge symmetry of nuclear forces and the low energy p-p scattering results.…”

Pion-Nucleus Interactions

“…The analysis is actually simplifi ed because the final state contains one zero-mass photon and two equal-mass neutrons, and the photon energy is uniquely related to the nn relative momentum (50,51). Because of resolution difficulties, three early measurements of the pho ton spectrum (52-54) each yielded sizeable uncertainties in the extracted value of ann' The kinematically complete measurement of Haddock et al (55,56) led to an estimate of ann = -16.7 ± 1.3 fm , where the quoted uncertainty is essentially statistical. The innovative Lausanne experiment (57-59) used the radiative nucleon capture reaction with a monoenergetic line at 129.404 MeV to provide the required stable energy scale and response function of the spectrometer.…”

Radiative pion capture in H2 , He3 , and Golak1, Skibiński2, Topolnicki3 et al. 2018Phys. Rev. C

“…As early as in 1951 Watson and Stuart [13] showed with quite simple dynamics that the corresponding photon spectrum very strongly depends on the properties of the nn interaction. Since then many theoretical efforts [14][15][16][17][18][19][20][21] combined with more and more precise measurements [22][23][24][25][26][27][28][29][30][31][32] have contributed decisively to our present day knowledge about a nn . Detailed information about this rich field can be found in the review by Šlaus, Akaishi, and Tanaka [33] and in the more recent review by Gårdestig [34], where also complementary efforts [35,36] to determine a nn from the 2 H(n, np)n reaction were reported.…”