Nuclear physics

An ultra-precise measurement of a transition in the hearts of thorium atoms gives physicists a tool to probe the forces that bind the universe.

Physicists have ruled out a mundane explanation for the strange findings of an old Soviet experiment, leaving open the possibility that the results point to a new fundamental particle.

Long-anticipated experiments that use light to mimic gravity are revealing the distribution of energies, forces and pressures inside a subatomic particle for the first time.

By measuring inflated helium nuclei, physicists have challenged our best understanding of the force that binds protons and neutrons.

Richard Feynman’s path integral is both a powerful prediction machine and a philosophy about how the world is. But physicists are still struggling to figure out how to use it, and what it means.

The positively charged particle at the heart of the atom is an object of unspeakable complexity, one that changes its appearance depending on how it is probed.

The strong force holds protons and neutrons together, but the theory behind it is largely inscrutable. Two new approaches show how it works.

The unexpected discovery of the double-charm tetraquark has given physicists a new tool with which to hone their understanding of the strongest of nature’s fundamental forces.

Groundbreaking results show that neutron stars of different masses may have the same size — upending astrophysical models.