Do Short-Range Correlations Cause the Nuclear EMC Effect in the Deuteron?

Area of Science:

• Nuclear Physics
• Particle Physics
• Quantum Chromodynamics

Background:

• The European Muon Collaboration (EMC) effect describes modifications to nucleon properties within atomic nuclei.
• Short-range correlations (SRCs) are configurations of nucleons within nuclei at very small distances.
• Understanding the origins of the EMC effect is crucial for nuclear structure theory.

Purpose of the Study:

• To disentangle the contributions of nucleon off-shell effects and Fermi motion to the deuteron's EMC effect.
• To investigate the role of nuclear binding and off-shell phenomena in nuclear models.
• To assess the connection between SRCs and the EMC effect.

Main Methods:

• Theoretical modeling incorporating nuclear binding and nucleon off-shell effects.
• Analysis of contributions from Fermi motion and off-shell dynamics.
• Examination of nucleon behavior in short-range correlated pairs.

Main Results:

• Fermi motion effects were found to be significantly larger than off-shell effects for nucleons in SRCs within the deuteron.
• The dominant contribution to the EMC effect in the deuteron originates from Fermi motion.
• The hypothesized direct causal link between SRCs and the EMC effect is questioned by these findings.

Conclusions:

• The study indicates that Fermi motion plays a more critical role in the deuteron's EMC effect than previously assumed.
• The results suggest that explanations for the EMC effect should place greater emphasis on kinematic effects like Fermi motion.
• The findings necessitate a re-evaluation of the relationship between nuclear structure phenomena like SRCs and modifications to nucleon properties.