Probing the core of the strong nuclear interaction

Area of Science:

• Nuclear Physics
• Quantum Chromodynamics
• Particle Physics

Background:

• The strong nuclear force binds atomic nuclei, originating from quark-gluon interactions described by quantum chromodynamics.
• Current models of nuclear interactions are well-defined at typical nucleon distances but lack constraints at shorter ranges.
• This limitation hinders the accurate description of high-density nuclear matter, such as in neutron star cores.

Purpose of the Study:

• To investigate nuclear interactions at short nucleon-nucleon distances.
• To explore a previously unaccessed kinematical regime using high-energy electron scattering.
• To understand the transition in nuclear forces at high relative nucleon momenta.

Main Methods:

• Utilized high-energy electron scattering experiments to probe nucleon pairs.
• Isolated nucleon pairs in short-distance, high-momentum configurations (relative momenta > 400 MeV/c).
• Analyzed the resulting data to observe changes in the nuclear force characteristics.

Main Results:

• Observed a transition in the nuclear interaction force as nucleon separation decreases.
• This transition is characterized by a shift from a spin-dependent tensor force to a spin-independent scalar force.
• The findings provide new insights into nuclear forces at sub-nucleonic distances.

Conclusions:

• High-energy electron scattering is effective for studying short-distance nuclear interactions.
• Results support the use of point-like nucleon models with effective interactions for dense nuclear systems.
• The study advances the understanding of nuclear matter at densities exceeding typical nuclear central densities.