== 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). * [: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 Software.MadGraph ====== * Logon to the Software.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: Software.MadAnalysis ([http://madgraph.phys.ucl.ac.be/cgi-bin/NewProcess/download.cgi Download it here]) * a Root-based package: Software.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 $% 1. * Signal * Events: [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-signal.lhe.gz Parton Level] || [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-signal.lhco.gz Detector Level] * Plots: [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-signal-lhe.pdf Parton Level] || [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-signal-lhco.pdf Detector Level] * Background * Events: [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-background.lhe.gz Parton Level] || [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-background.lhco.gz Detector Level] * Plots: [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-background-lhe.pdf Parton Level] || [http://cp3wks05.fynu.ucl.ac.be/twiki/pub/Physics/DiscoverTheHiggs/hww-background-lhco.pdf Detector Level] 1. Top associated production %$pp \to t\bar tH$% with %$H \to b \bar b$% * Signal + Background samples: * Events: [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] * 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] ====== Advanced exercises 2: Implementation of a new model in Software.MadGraph or [http://feynrules.phys.ucl.ac.be/ FeynRules] + Software.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 Software.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