Mediated by pions, the strong force holds the bits of the atomic nucleus together. Researchers think that this strong force is not affected by electrical charge in any unusual way. But, at present, the experimental evidence for the hypothesis is inadequate. The ASU physicist hopes that the greater precision of the spin-controlled experiment will help. At Los Alamos, Comfort and his colleagues send beams of pions into a target of butanol.
Butanol contains a large number of hydrogen atoms.
Hydrogen is a useful target because it has just one proton and one electron. They then fire beams of negative pions at the target. Neutral pions are emitted and make signals in large detector arrays. In a bit of scientific serendipity, they are getting two experiments for the price of one. Alarcon wants to find the exact distance at which the nucleons in deuterium begin to repel one another.