== Example: Z' Search at LHC == Choose the model {{{ model = Zprime }}} Setup aliases for partons (quarks and gluons) and leptons (electrons and positrons) {{{ alias pr = u:d:s:c:gl:U:D:S:C alias lepton = e1:E1 }}} Look at e+e--pairs created by colliding all possible parton pairs {{{ process zp_drell_yan = pr, pr => e1, E1 }}} Set values for the model parameters (mass and width of the Z', and set masses of particles summed over to zero) {{{ mZH = 1500 GeV wZH = 50 GeV ms = 0 mc = 0 }}} Define reasonable cuts {{{ cuts = all Pt >= 50 GeV [lepton] and all -2.5 <= Eta <= 2.5 [e1:E1] and all M >= 800 GeV [e1,E1] }}} Define the process scale {{{ scale = 1500 GeV }}} Set up the beams (full energy LHC with default lhapdf structure functions {{{ sqrts = 14 TeV beams = p,p => lhapdf }}} Integrate the cross sections in order to initialize the phase space grids for similation {{{ integrate (zp_drell_yan) { iterations = 6:20000 } }}} Choose weighted events for smoother histograms {{{ ?unweighted = false }}} Define title etc. as global variables, that will be used by PLOT {{{ $description = "A WHIZARD 2.0 Example. Cuts: $p_T^\ell\ge50 \textrm{ GeV}$, $M_{\ell\ell} \ge$800 GeV, $|\eta(\ell)|\le2.5$ \newline Using weighted events to produce smooth distributions." $ylabel = "$N_{\textrm{events}}$" }}} Allocate plots {{{ $title = "$Z'$ Drell-Yan dilepton peak $pp\to \ell\ell$" $xlabel = "$\theta^{\ell}$/GeV" histogram m_lepton (1 TeV, 2 TeV, 50 GeV) $title = "$Z'$ Drell-Yan: $p_T$ distribution of the $\ell$" $xlabel = "$p_T^{\ell}$/GeV" histogram pt_lepton (100 GeV, 2000 GeV, 100 GeV) $title = "$Z'$ Drell-Yan: Angular distribution of the $\ell$" $xlabel = "$\theta^{\ell}$/rad" histogram th_lepton (0, 3.1415, 0.157) }}} and tell WHIZARD what to store in them {{{ analysis = record m_lepton (eval M [e1,E1]) and record pt_lepton (eval Pt [e1]) and record th_lepton (eval Theta [e1]) }}} Simulate 100000 events {{{ n_events = 100000 simulate (zp_drell_yan) }}} and write results to file (and run LaTeX to produce plots etc.) {{{ write_analysis compile_analysis { $out_file = "Zprime.dat" } }}} WHIZARD will produce histograms in the [http://projects.hepforge.org/whizard/trac/attachment/wiki/ExampleZprime/Zprime.pdf PDF output] and as [http://projects.hepforge.org/whizard/trac/attachment/wiki/ExampleZprime/Zprime.dat data file]. The progress can be monitored on the terminal and in the [http://projects.hepforge.org/whizard/trac/attachment/wiki/ExampleZprime/whizard.log WHIZARD log file].