Reflections on the Origin of the EMC Effect

Abstract

In the 35 years since the European Muon Collaboration announced the astonishing result that the valence structure of a nucleus was very different from that of a free nucleon, many explanations have been suggested. The first of the two most promising explanations is based upon the different effects of the strong Lorentz scalar and vector mean fields known to exist in a nucleus on the internal structure of the nucleon-like clusters which occupy shell model states. The second links the effect to the modification of the structure of nucleons involved in short-range correlations, which are far off their mass shell. We explore some of the methods which have been proposed to give complementary information on this puzzle, especially the spin-dependent EMC effect and the isovector EMC effect, both proposed by Cloet, Bentz and Thomas. It is shown that the predictions for the spin dependent EMC effect, in particular, differ substantially within the mean-field and short-range correlation approaches. Hence the measurement of the spin dependent EMC effect at Jefferson Lab should give us a deeper understanding of the origin of the EMC effect and, indeed, of the structure of atomic nuclei.

Contribution to the Volume celebrating the contributions of Prof. Ernest Henley

References in corpus (10)

• Probing Cold Dense Nuclear Matter
• Nucleon-Nucleon Correlations, Short-lived Excitations, and the Quarks Within
• Short Range Correlations and the EMC Effect
• The Challenge of the EMC Effect: existing data and future directions
• Binding of Hypernuclei in the Latest Quark-Meson Coupling Model
• Isovector EMC effect explains the NuTeV anomaly
• Quark-Meson-Coupling (QMC) model for finite nuclei, nuclear matter and beyond
• Polarized EMC Effect in the QMC Model
• Superheavy Nuclei in the Quark-Meson-Coupling Model
• QCD and a New Paradigm for Nuclear Structure

Cited by in corpus (7)

• Imaging the nucleus with high-energy photons
• Exposing Novel Quark and Gluon Effects in Nuclei
• The Role of Baryon Structure in Neutron Stars
• Do short-range correlations cause the nuclear EMC effect in the deuteron?
• Gamow-Teller transitions and the spin EMC effect: the Bjorken sum-rule in medium
• Reflections on Chiral Symmetry within QCD
• The Gerasimov-Drell-Hearn sum-rule with nuclear targets