Model definition:

{{{
model = SM
}}}

Neutrino and quark containers:

{{{
alias n = n1:n2:n3
alias N = N1:N2:N3
alias q = u:d:s:c
alias Q = U:D:S:C
}}}

The Higgsstrahlung process

{{{
process zh = e1, E1 => Z, h
}}}

The missing-energy channel

{{{
process nnbb = e1, E1 => n, N, b, B
}}}

Other channels (for the 4-jet channels
we combine EW and QCD contributions)

{{{
process qqbb = e1, E1 => q, Q, b, B
process bbbb = e1, E1 => b, B, b, B
process eebb = e1, E1 => e1, E1, b, B
process qqtt = e1, E1 => q, Q, e3, E3
process bbtt = e1, E1 => b, B, e3, E3
}}}

Compilation (optional)

{{{
compile
}}}

The final LEP energy:

{{{
sqrts = 209 GeV
}}}

Set the input parameters

{{{
mH = 115 GeV
wH = 3.228 MeV
# Running b mass
mb = 2.9 GeV
me = 0
ms = 0
mc = 0
}}}


Soft-collinear cuts for the jets

{{{
cuts = all M >= 10 GeV [q,Q]
}}}

Integrate the processes:

{{{
integrate (zh) { iterations = 5:5000}

integrate(nnbb,qqbb,bbbb,eebb,
          qqtt,bbtt) { iterations = 12:20000 }
}}}

Define title etc. as global variables, that will be used by PLOT

{{{
$description =
  "A WHIZARD 2.0 Example. Using weighted events to speed things up."
$ylabel = "$N_{\textrm{events}}$"
}}}

Allocate plots

{{{
$title = "Invisible mass distribution in $e^+e^- \to \nu\bar\nu b \bar b$"
$xlabel = "$M_{\nu\nu}$/GeV"
histogram m_invisible (70 GeV, 130 GeV, 0.5 GeV)

$title = "$bb$ invariant mass distribution in $e^+e^- \to \nu\bar\nu b \bar b$"
$xlabel = "$M_{b\bar b}$/GeV"
histogram m_bb (70 GeV, 130 GeV, 0.5 GeV)
}}}

Define the analysis set-up:

{{{
analysis = record m_invisible (eval M [n,N]);
           record m_bb (eval M [b,B])
}}}

To speed things up we use weighted events for demonstration purposes.

{{{
?unweighted = false
}}}

Luminosity and simulation:

{{{
luminosity = 100

simulate (nnbb) 
}}}

Some more plots and simulations:

{{{
$title = "Dijet invariant mass distribution in $e^+e^- \to q \bar q b \bar b$"
$xlabel = "$M_{q\bar q}$/GeV"
histogram m_jj (70 GeV, 130 GeV, 0.5 GeV)

simulate (qqbb) { analysis = record m_jj (eval M / 1 GeV [combine [q,Q]]) }
}}}

Perform the analysis:

{{{ 
compile_analysis { $out_file = "lep_higgs.dat" }
}}}