REU Student: Jaime Winterton, Mentor: Todd Averett

Neutrons are of the most popularly recognized building blocks of matter. They were one of the first subatomic particles discovered in this century, and are known as an integral part of the atom. These seemingly unextraordinary neutral particles do have some mysteries that physicists today do not yet understand. Neutrons are composed of three quarks: two down quarks and one up quark. It was once a common belief that the spin of the neutron could be accounted for by adding the spins of its component quarks. However, recent experiemtns have shown that only 27% of the neutron's spin comes from these valence quarks. In additon to its component quarks and corresponding gluons, the neutron contains quark-antiquark pairs that exist for a short period of time and then vanish. It is possible that the missing spin of the neutron comes from the quark-antiquark pairs and gluons, but how the neutron's spin is produced by all these ingredients is impossible to calculate reliably. We must rely on experimental data to tell us how all the parts of the neutron contribut to its spin. Several experiments at Jefferson Lab are investigating possible sources of the neutron's missing spin, as well as its other characteristic properties. Our cell production facility will provide a necessary piece of equipment for these experiments.