The positively charged protons in atomic nuclei should actually repel each other, and yet even heavy nuclei with many protons and neutrons stick together. The so-called strong interaction is responsible for this. Scientists have now developed a method to precisely measure the strong interaction utilizing particle collisions in the ALICE experiment at CERN in Geneva.

The strong interaction is one of the four fundamental forces in physics. It is essentially responsible for the existence of atomic nuclei that consist of several protons and neutrons. Protons and neutrons are made up of smaller particles, the so-called quarks. And they too are held together by the strong interaction.

As part of the ALICE (A Large Ion Collider Experiment) project at CERN in Geneva, Prof. Laura Fabbietti and her research group at the Technical University of Munich have now developed a method to determine with high precision the forces that act between protons and hyperons, unstable particles comprising so-called strange quarks.

The measurements are not only groundbreaking in the field of nuclear physics, but also the key to understanding neutron stars, one of the most enigmatic and fascinating objects in our universe.

Comparison between theory and experiment

One of the biggest challenges in nuclear physics today is understanding the strong interaction between particles with different quark content from first principles, that is, starting from the strong interaction between the particles’ constituents, the quarks and the gluons, that convey the interaction force.

Story Source: Materials provided by Technical University of Munich (TUM). Note: Content may be edited for style and length.