Version 1 (modified by trac, 7 years ago) (diff)

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## Collider Event Generation

### Authors

• Johan Alwall (lecturer)

### Lectures

Find the pdf of the 3 x 1.5 hours lectures:

### References

• QCD and Collider Physics by Keith Ellis, James Stirling, Bryan Webber (Cambridge Monographs, 1996).
• [:FurtherReading:Perspectives on LHC physics, Ed. by G. Kane and A. Pierce].
• Pythia 6 Physics and Manual (excellent introduction to event generation, parton showers and hadronization).

### Basic exercises 1: Familiarize with Software.MadGraph

• Register with a valid e-mail address
• Feynman diagrams. Generate a few processes (with different QED + QCD couplings) trying to guess which diagrams appear:
• uu~&gt;tt~
• gg&gt;tt~
• gg&gt;tt~h (in SM and HEFT)
• uu~&gt;tt~bb~
• Subprocess identification. List all subprocesses contributing to:
• pp&gt;l+vljj
• pp&gt;tt~bb~
• pp&gt;tt~jj
• Look at the new physics models and check the particle and interactions content.

### Basic exercises 2: Calculate cross sections and generate events

• Generate events for a few selected processes (work in groups, pick one each), for Tevatron and LHC energies. Does the cross section scale as you expect?
• Compare cross sections with the processes of your neighbors. Do they differ as you would expect?
• Look at the generated plots. Are the distributions as you would expect? Discuss with your neighbors.

Example processes:

• ttbar production: pp &gt; tt~, QED=0
• W production: pp &gt; l+vl
• Z/gamma* production: pp &gt; e+e-
• g g &gt; (H &gt; e+ ve mu- vm~) (in HEFT model)
• p p &gt; (W+&gt;e+ ve) (W- &gt; mu- vm~) (important background to previous process)

Try out the Analysis Tools:

Study SM Higgs production at the LHC. Choose a channel and investigate signal and background, using either of the packages above:

1. The 2 lepton + missing Et final state: %%
• Signal
Events: Parton Level
Plots: Parton Level
• Background
Events: Parton Level <span style="color: #000000;">
 ​Detector Level
Plots: Parton Level <span style="color: #000000;">
 ​Detector Level
1. Top associated production %% with %%
• Signal + Background samples:
Events: Parton Level
Plots: Parton Level