Helium is the simplest element in the periodic table with more than one particle in its nucleus, yet state of the art theory and experiments on it don't add up.

Based on calculations using the laser frequency, the researchers found that the helium nucleus' charge radius is 1.6782 femtometers. Measurements made by bouncing electrons off the nucleus ...

Size of helium nucleus measured more precisely than ever before. Paul Scherrer Institute. Journal Nature DOI 10.1038/s41586-021-03183-1 ...

The helium-3 that PSI physicist and ETH Zurich professor Antognini is using in the current experiment lacks not only a neutron in the nucleus, but also both electrons that orbit this nucleus.

An atom consists of a heavy center, called the nucleus, made of particles called protons and neutrons. An atom has lighter ...

With this, the international research collaboration succeeded in determining the size of the helium nucleus around five times more precisely than was possible in previous measurements. The group is ...

The swelling helium nucleus, researchers say, is a sort of mini-laboratory for testing nuclear theory because it’s like a microscope — it can magnify deficiencies in theoretical calculations.

More information: Koichiro Yasuda et al, Neutrinos and Gamma Rays from Beta Decays in an Active Galactic Nucleus NGC 1068 Jet, Physical Review Letters (2025). DOI: 10.1103/PhysRevLett.134.151005 ...

Two protons and a neutron A discrepancy between two different measurements of the charge radius of the helium-3 nucleus may have been reconciled. (Courtesy: Shutterstock) Independent measurements of ...

The swelling helium nucleus, researchers say, is a sort of mini-laboratory for testing nuclear theory because it’s like a microscope—it can magnify deficiencies in theoretical calculations.