Schematic of Particle Detection (IMAGE)
Caption
RHIC physicists used collisions of protons with their spins aligned transverse (perpendicular) to their direction of motion (left) with an unpolarized proton beam (right) to search for the effects of the interaction between "like" color charges. They were looking for a lopsided production of particles called W bosons, but in the opposite direction to that observed by experiments measuring the effects of "unlike" color interactions. The scientists can't measure W particles directly because they decay quickly, in the case shown, into an electron (e) and a neutrino (ν) -- another notoriously difficult-to-detect particle. Instead they track a jet of particles that recoil in the opposite direction as the neutrino disappears, and add their energy to the energy of the electron to reconstruct each W. So far these experiments at RHIC's STAR detector reveal a hint of this effect of the repulsive color interaction -- a hint physicists hope to nail with future experiments.
Credit
Brookhaven National Laboratory
Usage Restrictions
OK for use with stories about this research
License
Licensed content