RPC Readout in the Belle Experiment

Emittance

As a particle returns to the same point on subsequent revolutions, it will map out an ellipse in phase space, defined by

Area = e

Twiss Parameters

An ensemble of particles will have a “bounding” e. This is referred to as the “emmitance” of the ensemble. Various definitions:

Electron machines:

Contains 39% of Gaussian particles

Proton machines:

Contains 95% of Gaussian particles

Usually leave p as a unit, e.g. E=12 p-mm-mrad

(FNAL)