Differential HBT Method to Analyze Rotation

Two particle correlations are studied in the reaction plane of peripheral relativistic heavy ion reactions where the initial state has substantial angular momentum. The earlier predicted rotation effect and Kelvin Helmholtz Instability, leads to space-time momentum correlations among the emitted particles. A specific combination of two particle correlation measurements is proposed, which can sensitively detect the rotation of the emitting system. Here the method is presented in simple few source models where the symmetries and the possibilities of the detection can be demonstrated in a transparent way.