== 2011 VUB Francqui Chair: LHC Phenomenology ==
=== Title ===
LHC phenomenology: a journey from standard model measurements to new physics discoveries
=== Authors ===
Fabio Maltoni (lecturer)
=== Lectures ===
Find the pdf of the 5 lectures:
* [attachment:VUB-francqui-public.pdf Public Lecture] : An expedition to the !TeraWorld : challenges and opportunities at the LHC
* [attachment:Francqui-1.pdf 1st and 2nd Lecture] : QCD at work: simulating events at the LHC
* [attachment:Francqui-2.pdf 3nd Lecture] : Precision physics and BEH boson phenomenology
* [attachment:Francqui-4.pdf 4th Lecture] : The importance of being top & Hunting for New Physics
=== References ===
* [http://www.hep.phy.cam.ac.uk/theory/webber/QCDbook.html QCD and Collider Physics] by Keith Ellis, James Stirling, Bryan Webber (Cambridge Monographs, 1996).
* [wiki:FurtherReading Perspectives on LHC physics, Ed. by G. Kane and A. Pierce].
=== Higgs notebooks ===
1. pp>H at LO (1-loop): details of the calculation (Mathematica Notebook) [attachment:HiggsGG-LO-mtfinite.nb HiggsGG-LO-mtfinite.nb]
1. pp>H at NLO: details of the calculation (Mathematica Notebook) [attachment:HiggsGG-NLO.nb higgsGG-NLO.nb]
1. pp>H at NLO: cross section evaluation for the LHC (Mathematica Notebook+PDF libraries to be compiled) [attachment:phenHiggs.tar.gz phenHiggs.tar.gz].
A summary of the results can be found in [attachment:Higgs.pdf Higgs.pdf].
=== MC Exercises ===
====== Basics : MC101 ======
A short introduction to the techniques of Monte Carlo integration. Exercises proposed during lecture are collected in this Mathematica Notebook: [attachment:mc101.nb mc101.nb].
====== Basic exercises 1: Familiarize with MadGraph ======
* Logon to the MadGraph web site and register: http://madgraph.hep.uiuc.edu.
* 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~>tt~
* gg>tt~
* gg>tt~h (in SM and HEFT)
* uu~>tt~bb~
* Subprocess identification. List all subprocesses contributing to:
* pp>l+vljj
* pp>tt~bb~
* pp>tt~jj
* Look at the new physics models and check the particle and interactions content.
* Advanced: Download the MG/ME package and play with the standalone version.
====== 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 > tt~, QED=0
* W production: pp > l+vl
* Z/gamma* production: pp > e+e-
* g g > (H > e+ ve mu- vm~) (in HEFT model)
* p p > (W+>e+ ve) (W- > mu- vm~) (important background to previous process)
====== Advanced exercises 1: The full simulation chain and advanced features ======
Try out the Analysis Tools:
* a Fortran-based package: MadAnalysis ([http://madgraph.phys.ucl.ac.be/cgi-bin/NewProcess/download.cgi Download it here])
* a Root-based package: ExRootAnalysis ([http://madgraph.hep.uiuc.edu/Downloads/ExRootAnalysis/ExRootAnalysis_V1.0.7.tar.gz Download it here])
* a Mathematica-based package: [http://v1.jthaler.net/olympicswiki/doku.php?id=lhc_olympics:analysis_tools Chameleon]
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: $ pp \to H\to W^+ W^- \to e^- \bar \nu_e \mu^+ \nu_\mu $
1.
* Signal
* Events: [attachment:hww-signal.lhe.gz Parton Level] || [attachment:hww-signal.lhco.gz Detector Level]
* Plots: [attachment:hww-signal-lhe.pdf Parton Level] || [attachment:hww-signal-lhco.pdf Detector Level]
* Background
* Events: [attachment:hww-background.lhe.gz Parton Level] || [attachment:hww-background.lhco.gz Detector Level]
* Plots: [attachment:hww-background-lhe.pdf Parton Level] || [attachment:hww-background-lhco.pdf Detector Level]
1. Top associated production $pp \to t\bar tH$ with $H \to b \bar b$
* Signal + Background samples:
* Events: [attachment:ttbb.lhe.gz Parton Level] || [attachment:ttbb.lhco.gz Detector Level]
* Plots: [attachment:ttbb-lhe.pdf Parton Level] || [attachment:ttbb-lhco.pdf Detector Level]
====== Advanced exercises 2: Implementation of a new model in MadGraph or [http://feynrules.phys.ucl.ac.be/ FeynRules] + MadGraph ======
Note that for these exercises you need to download the [http://madgraph.hep.uiuc.edu/Downloads/MG_ME_V4.4.56.tar.gz MadGraph/MadEvent package] (or [https://launchpad.net/madgraph5 MadGraph 5 package]) and work locally. You need a Fortran compiler (and for !MadGraph 5, Python v. 2.6 or 2.7).
=== For !FeynRules download and information, see the [http://feynrules.phys.ucl.ac.be/ FeynRules wiki] ===
* Implement a (part of a) Standard Model extension into MadGraph, specific for studying a given process. Generate events, study relevant distributions.
* Determine most relevant Standard Model backgrounds with identical final states (“non-reducible”). If not too complicated, generate backgrounds with cuts determined from signal distributions.
* Which other (“reducible”) backgrounds might be important?
* Can the signal be seen at Tevatron? At the LHC?
=== Animations ===
* [http://madgraph.hep.uiuc.edu/Event/ Interactive Flash version] Note you may want to zoom in!
* [http://madgraph.hep.uiuc.edu/Event/fast_collisionx6.avi Fast movie (.avi) of collision]
* [http://madgraph.hep.uiuc.edu/Event/collision.mov Guided movie (.mov) of collision]
* [http://www.thedailyshow.com/watch/thu-april-30-2009/large-hadron-collider John Ellis on Daily Show]
-- Main.FabioMaltoni - 2011-03-25