Successor of the COMPASS experiment will measure fundamental properties of the proton and its relatives

Protons are one of the main building blocks of the visible universe. Together with neutrons, they make up the nuclei of every atom. Yet, several questions loom about some of the proton’s most fundamental properties, such as its size, internal structure and intrinsic spin. In December 2020, the CERN Research Board approved the first phase (“phase-1”) of a new experiment that will help settle some of these questions. AMBER, or Apparatus for Meson and Baryon Experimental Research, will be the next-generation successor of the Laboratory’s COMPASS experiment.