RINGDEFITION: Particle #0
In OPAL1.5.0.1, the position of the particle #0 is shifted according to the OFFSETZ.
Dumping the particle distribution in the local frame, this particle alters the rms beam size. An example of the envelope with and without the particle #0 is shown in the attached picture. 
In OPAL 1.4.0-Jozef, this particle was removed from the sample step by step, but only in the H5 file. The beam rms from the .stat file is still evaluated with the particle #0.
The input file, beam distribution and field map are in Dropbox - OPAL-Ring-Problem/120deg_CFM