From Quarks to Nucleons in A=3 Nuclei

The A=3 mirror nuclei are a well understood isospin doublet with a large asymmetry (A/2Z = 1.5) which is exactly calculable for a given NN interaction. While 3He is a simple target for experiments, its mirror nucleus 3H is more difficult to handle due to its radioactivity. Fortunately, a Tritium gas target cell is available at Jefferson Lab's experimental Hall A for electron scattering experiments. In my talk, I will present preliminary results from two of the recently conducted experiments on Tritium in Hall A, MARATHON and SRC(e,e'p). The aim of the MARATHON experiment is measuring the proton to neutron structure function ratio, F2p/F2n, using deep inelastic scattering on the mirror nuclei, resulting in lower theoretical uncertainties than comparable measurements on hydrogen and deuterium. In parallel, it will determine the nucleon modification in nuclei (EMC effect) for Tritium and 3He.

The SRC(e,e'p) experiment is measuring the ratio of the proton momentum distributions in
3He to 3H to see the effect of neutron-proton short range correlated (SRC) pairs. While the naive expected ratio is two, the ratio of the number of protons in each nucleus, SRC pairing should shift equal numbers of protons from low momentum to high momentum, increasing the low momentum ratio, and decreasing the high momentum ratio. This means that, counterintuitively, the single proton in 3H should have higher average momentum than the two protons in 3He.