WHIZARD

Gaussian or Breit wigner distribution

Asked by Yehia Abdelaziz

In generating events of the form:

process eeTozz = e1, E1 => Z, Z
process Z_dec1 = Z => e2, E2
process Z_dec2 = Z => numu, numubar

unstable Z(Z_dec1,Z_dec2)

The resulting distribution of the mass of the muon pair doesn't have a gaussian or breit wigner shape. What is the reason for this?

Question information

Language:
English Edit question
Status:
Solved
For:
WHIZARD Edit question
Assignee:
Juergen Reuter Edit question
Last query:
Last reply:
Revision history for this message
Juergen Reuter (j.r.reuter) said : 		#1

Hi Yehia,
a factorized approach (using the unstable) feature in WHIZARD always uses the narrow-width approximation, to see a Breit-Wigner or a Gaussian, you need to use full matrix elements, potentially with restrictions.
Cheers,
    JRR (Juergen)

Revision history for this message
Juergen Reuter (j.r.reuter) said : 		#2

Seems to be solved.