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| 3 | == Basics of QCD for the LHC, Cern Latin American School 2013 == |
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| 5 | 4 Lectures are given on QCD and MC's developments for the LHC. |
| 6 | |
| 7 | The PDF of the lectures be found here: |
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| 9 | [attachment:QCD1.pdf QCD1 : Intro and QCD fundamentals] |
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| 11 | [attachment:QCD2.pdf QCD2: QCD in the final state] |
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| 13 | [attachment:QCD3.pdf QCD3: QCD in the initial state] |
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| 15 | [attachment:QCD4.pdf QCD4: From accurate QCD to useful QCD] |
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| 17 | The examples and exercises are related to physics at the LHC. |
| 18 | === Basic aspects of QCD === |
| 19 | ===== Various Tests and exercises ===== |
| 20 | |
| 21 | A collection of test, exercises, and web applications on pQCD can be found in [attachment:QCD-exercises.pdf QCD-exercises.pdf]. |
| 22 | |
| 23 | ===== Exercise on recursive relations ===== |
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| 25 | Think about the computation of q \bar q + n \gamma in a recursive way, by trying not calculate the same quantities twice. Show that the complexity of the calculation goes from n! (factorial) to 2^{n-1} (exponential) . |
| 26 | === Going NLO === |
| 27 | |
| 28 | 1. pp>H at LO (1-loop): details of the calculation (Mathematica Notebook) [attachment:HiggsGG-LO-mtfinite.nb HiggsGG-LO-mtfinite.nb] |
| 29 | 1. pp>H at NLO: details of the calculation (Mathematica Notebook) [attachment:HiggsGG-NLO.nb higgsGG-NLO.nb] |
| 30 | 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]. |
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| 32 | A summary of the results can be found in [attachment:Higgs.pdf Higgs.pdf]. |
| 33 | |
| 34 | === Selected exercises on QCD that can be solved with a Matrix Element generator. === |
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| 36 | * [wiki:DeadCone Radiation from heavy quarks]: the dead cone in $e^+e^- \to Q \bar Q g$. |
| 37 | * [wiki:GluonSpin Spin of the gluon]: Vector vs scalar in the angular correlations of $ e^+ e^- \to$ 4 jets. |
| 38 | * [wiki:2Jets Jets] : Di-jet kinematics and rates in pp collisions. |
| 39 | * [wiki:3Jets 3 Jets] : Energy distributions in 3-jet events in pp collisions. |
| 40 | * [wiki:Tt top production] : $t \bar t$ production, Tevatron vs LHC. |
| 41 | * [wiki:WAsymm Drell-Yan]: rapidity asymmetry at the Tevatron and LHC. |
| 42 | * [wiki:TopDecaySpinCorrelations Spin correlations in top decay], by [http://www.hep.phy.cam.ac.uk/theory/webber/ Bryan Webber]. |
| 43 | |
| 44 | === Monte Carlo integration === |
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| 46 | 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]. |
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| 48 | === LHC Phenomenology === |
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| 50 | * [wiki:DiscoverTheHiggs SM Higgs discovery at the LHC]: Three important channels |
| 51 | * [wiki:WarmingUpChallenge Simple Black Boxes]: New gauge bosons |
| 52 | |
| 53 | === How to familiarize with MadGraph === |
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| 55 | All exercises proposed can be "solved" or checked with MadGraph / MadEvent. Here is how to familiarize with the code. |
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| 57 | * Logon to the MadGraph web site and register. |
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| 59 | * Familiarize with the code by generating a few processes in QED and QCD trying to guess which diagrams appear. What is the minimum number of jets have to be asked for in $e^+e^-$ collisions so that the triple gauge vertex appear? |
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| 61 | * Look at the new physics models and check the particle and interactions content. |
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| 63 | * Generate events for a few selected processes and look at the plots: |
| 64 | * ttbar production with decays: pp>tt~>bb~mu+e-ve~vm |
| 65 | * VV production: pp>VV> leptons, with V=Z,W. |
| 66 | * Single top + Higgs: pp>tHj (QCD=0, QED=3, j=gudsc,p=gudscb). Show that there is a large negative interference between the diagrams |
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| 68 | -- Main.FabioMaltoni - 2011-09-09 |
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