New probe of proton spin structure: How quarks of different flavors contribute to spin

Scientists hoping to unravel the mystery of proton spin at the Relativistic Heavy Ion Collider (RHIC), a 2.4-mile-circumference particle accelerator at Brookhaven National Laboratory, have a new tool at their disposal -- the first to directly explore how quarks of different types, or "flavors," contribute to the overall spin of the proton.