Alpha-Alpha Scattering at Low Energies

Abstract

PICKUP BEHAVIOR 123 lengths in the wave functions for the alpha particle in Li 6 , and for the proton in He 3 , respectively; rj is defined, approximately, by tam7 = 7/Z+l/Zfo. This result has the same form as the deuteron pickup angular distribution. However, because Z is smaller than the corresponding K, appropriate for deuteron pickup, the oscillations in the backward direction can be fitted only with a much larger radius than for the other process. This is illustrated by curve d in Fig. 4, computed from the relation above, at 18.5 Mev for ro=8.4XlO~1 3 cm, with arbitrary normalization. Also, the angular distribution should shift considerably on lowering the proton energy. This is illustrated by curve c, in Fig. 3, calculated for the same radius, at 15 Mev. The impossibly large radius, and the fact that no shift is observed between the angular distributions at the two energies, suggest that the minimum, observed N. P. HEYDENBURG AND G. M. TEMMER

Ab initio alpha–alpha scattering

“…Fig. 3 shows the phase shifts for S-wave scattering versus laboratory energy at next-to-leading order (NLO) in chiral effective field theory, next-to-next-to-leading order (NNLO), and the comparison with experimental data [21][22][23][24]. The results at leading order (LO) do not include Coulomb effects and so have significantly different behavior near threshold and are not shown.…”

“…The computational effort needed for the A 1 -body + A 2 -body problem is roughly [21][22][23][24]. In the inset we show next-to-leading-order calculations using halo effective field theory [32].…”

Quantitative complementarity in two-path interferometry

“…In Ref. [16], α-α scattering was measured at center-ofmass energies E = 75, 150 and 200 keV. Those by Bromley et al [17] refer to C 12 + C 12 at E = 3 and 5 MeV and to O 16 + O 16 at E = 7, 8.8 and 10 MeV.…”

Lessons from two paradigmatic developments; Rutherford's nuclear atom and halo nuclei

“…All this in the language of two decades after 1911, when quantum mechanics and spin statistics had become part of the paradigm. Temmer addresses this seemingly missed opportunity in his 1988 paper "How Rutherford Missed Discovering Quantum-Mechanical Identity", see [8].…”

“…This happened after the interrupting world war, the year before Rutherford left for Cambridge, opening up a new stage in the history of modern alchemy. In 1956, nearly half a century later, Heydenburg and Temmer [8] measured complete angular distributions for low energy alpha particles from electrostatic generators, on 4 He target. Below a relative energy of 400 keV, i.e.…”