The isospin and neutron-to-proton excess dependence of short-range correlations

Ryckebusch, Jan  (Department of Physics and Astronomy, Ghent University, Belgium) ; Cosyn, Wim  (Department of Physics and Astronomy, Ghent University, Belgium) ; Stevens, Sam (Department of Physics and Astronomy, Ghent University, Belgium) ; Casert, Corneel (Department of Physics and Astronomy, Ghent University, Belgium) ; Nys, Jannes (Department of Physics and Astronomy, Ghent University, Belgium)

12 March 2019

Abstract: We provide a systematic study of the isospin composition and neutron-to-proton (NZ) ratio dependence of nuclear short-range correlations (SRC) across the nuclear mass table. We use the low-order correlation operator approximation (LCA) to compute the SRC contribution to the single-nucleon momentum distributions for 14 different nuclei from A=4 to A=208 . Ten asymmetric nuclei are included for which the neutrons outnumber the protons by a factor of up to 1.54. The computed momentum distributions are used to extract the pair composition of the SRC. We find that there is a comprehensive picture for the isospin composition of SRC and their evolution with nucleon momentum. We also compute the non-relativistic kinetic energy of neutrons and protons and its evolution with nuclear mass A and NZ . Confirming the conclusions from alternate studies it is shown that the minority species (protons) become increasingly more short-range correlated as the neutron-to-proton ratio increases. We forge connections between measured nucleon-knockout quantities sensitive to SRC and single-nucleon momentum distributions. It is shown that the LCA can account for the observed trends in the data, like the fact that in neutron-rich nuclei the protons are responsible for an unexpectedly large fraction of the high-momentum components.


Published in: Physics letters B 792 (2019) 21-28
Published by: Elsevier
DOI: 10.1016/j.physletb.2019.03.016
License: CC-BY-3.0



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