Dear MC conveners
I am playing around with Zqq events in Herwig/Sherpa. I would like to come up with a “baseline” Zqq configuration, before playing with various MC tunes.
I have the following questions, for Herwig and Sherpa, ordered by importance.
- I could only manage to set a max proper lifetime for unstable particles, but this is not exactly what we want. Instead, we want to be able to specify that only particles with a decay within a cylinder R0,z0 may decay (and the be considered unstable, with a corresponding "unstable "status code), otherwise it is stable, as done in Pythia in the example below:
- How can we set vertex position and time smearing?
As in e.g, pythia8, https://github.com/HEP-FCC/FCC-config/blob/winter2023/FCCee/Generator/Pythia8/p8_ee_Zss_ecm91_Kspipi_pimu.cmd#L17-L19
- Is there a way to define beam energy spread, as done for example in whizard:
! beams = e1, E1 => gaussian
gaussian_spread1 = 0.221%
gaussian_spread2 = 0.221%
If not available, can the above features be implemented?