Axial Coupling of the Neutron (IMAGE) University of North Carolina at Chapel Hill Caption The neutron, composed of three colored quarks, ends its life by decaying into a proton, and emitting an electron and neutrino (white rays). The axial coupling gives the strength of the weak interaction (wavy line) which mediates this process, within the neutron. Credit Amy Nicholson Usage Restrictions The image may be used as long as the photo credit is given License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.