Description

The particle table contains the following particle attributes: nominal mass, charge, life time, width, and particle - antipart. relation.

In every ALPHA job, an internal particle table is built which combines data from the following sources:

• Data cards described below.
• The ``standard'' ALEPH particle table stored on the data base. This table contains all standard model particles (three generations) which can be produced at LEP energies, plus some exotic particles.
• The ``MC'' particle table stored in the run record of MC event files. This table contains the standard table, and if necessary, extra particles specific to the MC generator.

If particle attribute values from different sources do not agree, they are taken from data cards with highest and from the MC table with lowest priority. The standard printout produced at job termination indicates where the values come from.

New particles can be defined with the PNEW card (see below), or by using their names in ALPHA subroutine calls. If particles are created in subroutine calls, a warning message is printed.