Event Shapes

In this section we study general event shape variables: sphericity, thrust, Fox-Wolfram moments, and jet masses. These measures are implemented in the routines PYSPHE, PYTHRU, PYFOWO and PYJMAS, respectively.

Each event is assumed characterized by the particle four-momentum vectors $p_i = (\mathbf{p}_i, E_i)$, with $i = 1, 2, \cdots , n$ an index running over the particles of the event.