ParticleGun: fix pdgid and status of incoming particles
Hello,
In the definition of ad-hoc beam particles, it seems that the PDG ID and status have been swapped (ATLMCPROD-10688). Concerning the ad-hoc beam energy, that seems a bit overkill to grab it from runArgs, so I didn't dare touch this. This MR should have no consequence for the generated final state particles of interest.
Tagging @averbyts and @abuckley for expert review.
Cheers, Bertrand