Table of Contents

Modifying the properties of particles in ParticleTable.txt

Idea

You can modify the properties of particles, which are stored in the DDDB under param/ParticleTable.txt. This can be useful e.g. in Gauss.

How (not) to

This example is for Gauss v40r2p3 and does not fully seem to work. In Gauss-Job.py (or similar) write:

from Configurables import LHCb__ParticlePropertySvc as ParticlePropertySvc
ParticlePropertySvc().Particles = [ "K*_2(1430)0         153         315  0.0        0.100000   1.0e-10                    K_2*0         315        0.0", 
                                    "K*_2(1430)~0        154        -315  0.0        0.100000   1.0e-10               anti-K_2*0        -315        0.0" ]
 
ApplicationMgr().ExtSvc    += [ ParticlePropertySvc() ]

if you want to modify the properties of the K*_2(1430) and its antiparticle. The columns are:

Particle GeantID PDGID CHARGE MASS(GeV) LIFETIME(s) EVTGENNAME PYTHIAID MAXWIDTH

If this does not give you what you want, try adding in your someNumber.opts file:

ParticlePropertySvc.Particles = { "K*_2(1430)0         153         315  0.0        0.100000   1.0e-10                    K_2*0         315        0.0", 
                                  "K*_2(1430)~0        154        -315  0.0        0.100000   1.0e-10               anti-K_2*0        -315        0.0" };

Check

At the beginning of your Gauss job, you should then see something like:

ParticlePropertySvc        INFO Opened particle properties file : conddb:///param/ParticleTable.txt
ParticlePropertySvc     SUCCESS  Add/Modify the particle:  name='K*_2(1430)0' geant=153 jetset=315 charge=0 mass=0.1 ltime=1e-10 evtgen='K_2*0' pythia=315 maxwid=0
ParticlePropertySvc        INFO Properties have been redefined for 1 particles : [ 'K*_2(1430)0' ]
ParticlePropertySvc     SUCCESS  Add/Modify the particle:  name='K*_2(1430)~0' geant=154 jetset=-315 charge=0 mass=0.1 ltime=1e-10 evtgen='anti-K_2*0' pythia=-315 maxwid=0
ParticlePropertySvc        INFO Properties have been redefined for 1 particles : [ 'K*_2(1430)~0' ]