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| 2 | |
| 3 | == 2011 VUB Francqui Chair: LHC Phenomenology == |
| 4 | |
| 5 | === Title === |
| 6 | |
| 7 | LHC phenomenology: a journey from standard model measurements to new physics discoveries |
| 8 | |
| 9 | === Authors === |
| 10 | |
| 11 | Fabio Maltoni (lecturer) |
| 12 | |
| 13 | === Lectures === |
| 14 | |
| 15 | Find the pdf of the 5 lectures: |
| 16 | |
| 17 | * [attachment:VUB-francqui-public.pdf Public Lecture] : An expedition to the !TeraWorld : challenges and opportunities at the LHC |
| 18 | * [attachment:Francqui-1.pdf 1st and 2nd Lecture] : QCD at work: simulating events at the LHC |
| 19 | * [attachment:Francqui-2.pdf 3nd Lecture] : Precision physics and BEH boson phenomenology |
| 20 | * [attachment:Francqui-4.pdf 4th Lecture] : The importance of being top & Hunting for New Physics |
| 21 | |
| 22 | === References === |
| 23 | |
| 24 | * [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). |
| 25 | * [:FurtherReading:Perspectives on LHC physics, Ed. by G. Kane and A. Pierce]. |
| 26 | |
| 27 | === Higgs notebooks === |
| 28 | |
| 29 | 1. pp>H at LO (1-loop): details of the calculation (Mathematica Notebook) [attachment:HiggsGG-LO-mtfinite.nb HiggsGG-LO-mtfinite.nb] |
| 30 | 1. pp>H at NLO: details of the calculation (Mathematica Notebook) [attachment:HiggsGG-NLO.nb higgsGG-NLO.nb] |
| 31 | 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]. |
| 32 | |
| 33 | A summary of the results can be found in [attachment:Higgs.pdf Higgs.pdf]. |
| 34 | |
| 35 | === MC Exercises === |
| 36 | |
| 37 | ====== Basics : MC101 ====== |
| 38 | |
| 39 | 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]. |
| 40 | |
| 41 | ====== Basic exercises 1: Familiarize with Software.MadGraph ====== |
| 42 | |
| 43 | * Logon to the Software.MadGraph web site and register: http://madgraph.hep.uiuc.edu. |
| 44 | * Register with a valid e-mail address |
| 45 | * Feynman diagrams. Generate a few processes (with different QED + QCD couplings) trying to guess which diagrams appear: |
| 46 | * uu~>tt~ |
| 47 | * gg>tt~ |
| 48 | * gg>tt~h (in SM and HEFT) |
| 49 | * uu~>tt~bb~ |
| 50 | * Subprocess identification. List all subprocesses contributing to: |
| 51 | * pp>l+vljj |
| 52 | * pp>tt~bb~ |
| 53 | * pp>tt~jj |
| 54 | * Look at the new physics models and check the particle and interactions content. |
| 55 | * Advanced: Download the MG/ME package and play with the standalone version. |
| 56 | ====== Basic exercises 2: Calculate cross sections and generate events ====== |
| 57 | |
| 58 | * 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? |
| 59 | * Compare cross sections with the processes of your neighbors. Do they differ as you would expect? |
| 60 | * Look at the generated plots. Are the distributions as you would expect? Discuss with your neighbors. |
| 61 | |
| 62 | Example processes: |
| 63 | * ttbar production: pp > tt~, QED=0 |
| 64 | * W production: pp > l+vl |
| 65 | * Z/gamma* production: pp > e+e- |
| 66 | * g g > (H > e+ ve mu- vm~) (in HEFT model) |
| 67 | * p p > (W+>e+ ve) (W- > mu- vm~) (important background to previous process) |
| 68 | ====== Advanced exercises 1: The full simulation chain and advanced features ====== |
| 69 | |
| 70 | Try out the Analysis Tools: |
| 71 | * a Fortran-based package: Software.MadAnalysis ([http://madgraph.phys.ucl.ac.be/cgi-bin/NewProcess/download.cgi Download it here]) |
| 72 | * a Root-based package: Software.ExRootAnalysis ([http://madgraph.hep.uiuc.edu/Downloads/ExRootAnalysis/ExRootAnalysis_V1.0.7.tar.gz Download it here]) |
| 73 | * a Mathematica-based package: [http://v1.jthaler.net/olympicswiki/doku.php?id=lhc_olympics:analysis_tools Chameleon] |
| 74 | |
| 75 | Study SM Higgs production at the LHC. Choose a channel and investigate signal and background, using either of the packages above: |
| 76 | 1. The 2 lepton + missing Et final state: %$ pp \to H\to W^+ W^- \to e^- \bar \nu_e \mu^+ \nu_\mu $% |
| 77 | 1. |
| 78 | * Signal |
| 79 | * Events: [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-signal.lhe.gz Parton Level] || [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-signal.lhco.gz Detector Level] |
| 80 | * Plots: [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-signal-lhe.pdf Parton Level] || [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-signal-lhco.pdf Detector Level] |
| 81 | * Background |
| 82 | * Events: [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-background.lhe.gz Parton Level] <span style="color: #000000;">|| </span>[http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-background.lhco.gz Detector Level] |
| 83 | * Plots: [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-background-lhe.pdf Parton Level] <span style="color: #000000;">|| </span>[http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-background-lhco.pdf Detector Level] |
| 84 | 1. Top associated production %$pp \to t\bar tH$% with %$H \to b \bar b$% |
| 85 | * Signal + Background samples: |
| 86 | * Events: [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/ttbb.lhe.gz Parton Level] || [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/ttbb.lhco.gz Detector Level] |
| 87 | * Plots: [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/ttbb-lhe.pdf Parton Level] || [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/ttbb-lhco.pdf Detector Level] |
| 88 | ====== Advanced exercises 2: Implementation of a new model in Software.MadGraph or [http://feynrules.phys.ucl.ac.be/ FeynRules] + Software.MadGraph ====== |
| 89 | |
| 90 | 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). |
| 91 | === For !FeynRules download and information, see the [http://feynrules.phys.ucl.ac.be/ FeynRules wiki] === |
| 92 | * Implement a (part of a) Standard Model extension into Software.MadGraph, specific for studying a given process. Generate events, study relevant distributions. |
| 93 | * Determine most relevant Standard Model backgrounds with identical final states (“non-reducible”). If not too complicated, generate backgrounds with cuts determined from signal distributions. |
| 94 | * Which other (“reducible”) backgrounds might be important? |
| 95 | * Can the signal be seen at Tevatron? At the LHC? |
| 96 | === Animations === |
| 97 | * [http://madgraph.hep.uiuc.edu/Event/ Interactive Flash version] Note you may want to zoom in! |
| 98 | * [http://madgraph.hep.uiuc.edu/Event/fast_collisionx6.avi Fast movie (.avi) of collision] |
| 99 | * [http://madgraph.hep.uiuc.edu/Event/collision.mov Guided movie (.mov) of collision] |
| 100 | * [http://www.thedailyshow.com/watch/thu-april-30-2009/large-hadron-collider John Ellis on Daily Show] |
| 101 | |
| 102 | -- Main.FabioMaltoni - 2011-03-25 |
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