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 PDF output and as data file. The progress can be monitored on the terminal and in the WHIZARD log file.
Attachments (4)
- Zprime.dat (6.5 KB) - added by 15 years ago.
- Zprime.sin (2.8 KB) - added by 14 years ago.
- whizard.log (10.6 KB) - added by 14 years ago.
- Zprime.pdf (27.0 KB) - added by 13 years ago.
Download all attachments as: .zip