The Spectator Tagging Project develops the capabilities for high-energy electron scattering experiments with polarized light ions (deuteron 2H, 3He) and detection of spectator nucleons (protons, neutrons) at a future Electron-Ion Collider (EIC). Such experiments address basic questions of nuclear and strong interaction physics:
Event generators and analysis tools for electron-deuteron collisions with spectator nucleon tagging are being developed for process simulations at EIC. The materials are presently organized in the following categories:
Physicists develop a universal function that suggests that proton-neutron pairs in the nucleus may explain why quarks inside nuclei have lower average momenta than predicted.
A new study has confirmed that increasing the number of neutrons as compared to protons in the atom’s nucleus also increases the average momentum of its protons.
The determination of the pressure distribution inside the proton is the first measurement of a mechanical property of a subatomic particle. The measurement found that the proton’s building blocks, quarks, are subjected to a pressure of 100 decillion Pascal (1035) near the center of a proton, which is about 10 times greater than the pressure in the heart of a neutron star.