Matrix element integration over 2 final state neutrinos with MG5 standalone
Dear MG5 experts,
I generated a standalone for WW production, with the Ws decaying leptonically into first and second generations, and I'm trying to integrate over the 2 final state neutrinos momentum components.
I'm using scipy.nquad and the integration is taking forever, returning the warning "Integral is probably divergent or slowly convergent".
Do you have any tips to speed up the computations? You can find my piece of code below.
Thank you, hope this was the right place where to ask this question, even if not involving MG5 problems.
Matteo
Here's the part of code doing the integration:
proc_id = 0 # e+ processes
pdgf = [-11,12,13,-14]
if e_pdg < 0: # e- processes
pdgf = [11,-12,-13,14]
pdgin_list = [[1,-1]
def integrand (pvey,pvex,
# Neutrinos momenta
ve_mom = [(pvex*
pvmx = -(e_mom[
pvmy = -(e_mom[
vm_mom = [(pvmx*
# Initial state
pfz = e_mom[3]
Ef = e_mom[0]
in1 = [(Ef+pfz)
in2 = [(Ef-pfz)
# Matrix element computation
tmp = 0.
for pin in [[in1,in2]
return tmp
# Integration limits
pzmax = ((1.3e4-
def limz (pvez):
return [-pzmax-
def limx (pvmz,pvez):
pxmax = ((1.3e4-
return [-pxmax,pxmax]
def limy (pvex,pvmz,pvez):
pymax = ((1.3e4-
return [-pymax,pymax]
try:
meint = integrate.nquad (integrand,
except:
print (myrank,pzmax)
delta_sm = weight*
sigma_meas += delta_sm
Question information
- Language:
- English Edit question
- Status:
- Solved
- Assignee:
- No assignee Edit question
- Solved by:
- Olivier Mattelaer
- Solved:
- Last query:
- Last reply: