Experiments at Jefferson Lab and MIT Probe for Strange Quarks in the Proton

JUN 01, 1999

If you can measure a parts‐per‐million parity violation in the elastic scattering of electrons off protons with enough precision, you get to look at the strangeness structure of the proton. These demanding experiments are under way at accelerators old and new.

DOI: 10.1063/1.882694

Bertram M. Schwarzschild

The simplest description of the proton in terms of constituents regards it as a bound state of the three “Valence” quarks that account for its quantum numbers: two up quarks, each with charge $+ \frac{2}{3} e,$ and one down quark, with charge $- \frac{1}{3} e.$ But we know that’s too naive. Experiments over many years have shown that quarks carry only about half the proton’s linear momentum and a quarter of its angular momentum.

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