The scientific legacy of J.P. Elliott

Abstract

one of the towering figures of nuclear physics of the second half of the twentieth century, died on the 21st of October 2008. Obituaries appeared in the British press but relatively little attention was paid by the international scientific community to Elliott's contributions. Given their importance, in particular for theoretical nuclear physics, it seems appropriate to reflect here, two years after his death, on the scientific legacy left by Phil Elliott.

Rotational bands beyond the Elliott model

“…One can think of 10 Be as two α clusters with two valence neutrons in molecular orbitals [89,90]. Experimentally, 10 Be contains two distinct K = 0 rotational bands [91][92][93], which are also expected from, e.g., antisymmetrized molecular dynamics [89] and NCSM calculations [20,[39][40][41].…”

“…For the many-body calculation we used the BIGSTICK code [56,57], which solves the large, sparse, many-body eigenvalue problem via the Lanczos algorithm [58], and which uses an M-scheme basis, that is, the many-body basis fixes the total M (or eigenvalue of Ĵz ), and the overall parity, but no other quantum numbers. We carried out calculations of 7 Be and 8 Be at N max = 10, while the 'unnatural' parity states of 9 Be we computed at N max = 9, and 10 Be we computed in a N max = 8 space. Finally, we studied 20 Ne in an N max = 4 space.…”

“…One can think of 10 Be as two α clusters with two valence neutrons in molecular orbitals [89,90]. Experimentally, 10 Be contains two distinct K = 0 rotational bands [91][92][93], which are also expected from, e.g., antisymmetrized molecular dynamics [89] and NCSM calculations [20,[39][40][41]. In the cluster picture, the molecular orbitals for the valence neutrons can be loosely related either to spherical shell model p-shell orbitals for the ground-state band, or sd-shell orbitals for the excited band.…”

“…The Bohr-Mottelson model represents the nucleus as an undifferentiated fluid. Working under Giulio Racah, Phil Elliott [10] considered an alternative quadrupole operator Q2m , one which is equivalent to the mass quadrupole operator Q2m when restricted to a single harmonic oscillator single shell, but which does not connect different oscillator shells. These Q2m , taken together with the orbital angular momentum components L1m , close under commutation.…”

James Philip Elliott. 27 July 1929—21 October 2008

“…A special thanks goes also to Phil's long-time collaborator, Tony Evans. A review of Phil's legacy appeared in Van Isacker (2011) and was the basis for the description of his scientific achievements in this memoir. Material from this review was adapted with permission from Elsevier.…”