Experimental tests of the SM (1): the strong force FK8022, Lecture 5 Core texts: Review of Particle Physics : QCD minireview Further reading: Quarks and Leptons, an Introductory Course in Modern Physics, Halzen and Martin.

Free parameters of the Standard Model 19 free parameters (massless neutrino version). SM tests require both collider and non-colliders Masses ParameterValueMethod mumu 1.9 MeVLattice mdmd 4.4 MeVLattice msms 87 MeVLattice mcmc 1.3 MeVCollider mbmb 4.24 MeVCollider mtmt 173 GeVCollider meme 511 keVNon-collider mm 106 MeVNon-collider mm 1.78 GeVCollider mzmz 91.2 GeVCollider mHmH 125 GeVCollider Couplings ParameterValueMethod  non-collider + collider GFGF 1.17x10 -5 Non-collider ss 0.12Lattice + collider ParameterValueMethod    (CKM) 13.1 o Collider    (CKM) 2.4 o Collider    (CKM) 0.2 o Collider  (CKM-CPV) 0.995Collider  (strong CP) ~0Non-collider Flavour and CP violation

Free parameters of the Standard Model Masses ParameterValueMethod mumu 1.9 MeVLattice mdmd 4.4 MeVLattice msms 87 MeVLattice mcmc 1.3 MeVCollider mbmb 4.24 MeVCollider mtmt 173 GeVCollider meme 511 keVNon-collider mm 106 MeVNon-collider mm 1.78 GeVCollider mzmz 91.2 GeVCollider mHmH 125 GeVCollider Couplings ParameterValueMethod  non-collider + collider GFGF 1.17x10 -5 Non-collider ss 0.12Lattice + collider ParameterValueMethod    (CKM) 13.1 o Collider    (CKM) 2.4 o Collider    (CKM) 0.2 o Collider  (CKM-CPV) 0.995Collider  (strong CP) ~0Non-collider Flavour and CP violation Collider tests of the strong and electroweak sectors (this lecture). CKM, CPV (lecture 6), Higgs (lectures 8,9)

AcceleratorColliding particles Beam energy (GeV) LabRunning period Physics topics LHC pp 4000, 7000(2015) CERN2008-Higgs, general purpose Tevatron pp 1000Tevatron Top quark, general purpose HERA ep 30( e ), 920 (p)DESY QCD, general purpose CEBAF ep 6( e - )+fixed target JLAB1994-QCD, flavour LEP1,2 e+e-e+e CERN EW,general purpose SLC e+e-e+e- 45SLAC EW, general purpose DAFNE e+e-e+e- 0.5Frescati1999-QCD, flavour PEP-II/Babar e+e-e+e- 9( e - ),3( e + )SLAC Flavour KEKB/Belle e+e-e+e- 8( e - ),4( e + )KEK Flavour BEPC e+e-e+e- 3.7Beijing2008-QCD, flavour Recent and current colliders Diverse and complementary collider program

Strategy for QCD tests

Collider environments to study QCD

Lepton-nucleon deep-inelastic scattering P e e.- ’ P p p P P 

= data point x Q2Q2 e - P e e-e- p P p parton xP p parton selected data

DIS cross section

10 F 2 for different scenarios of proton structure x F2F2 H1 experiment at HERA

Quasi-free quarks and Bjorken scaling

Bjorken scaling and the quark parton model Quasi-free quarks Strongly bound quarks

The final part of the story: perturbative QCD processes + + +

Scaling violations HERA Low energy DIS Standard Model

Extraction of  s

Testing QCD at e + e - colliders

Event shapes in e + e -

Event shapes

Event shape measurements at LEP Rates over several orders of magnitude. Excellent description of QCD-based models.

Extraction of  s e+e+ e-e-

More measurements of  s Lecture 9

QCD at hadron-hadron colliders p p hadrons

Jet production at the LHC jet

Summary of QCD tests CollisionObservableDescribed by pQCD  s (M z ) HERA (ep) Structure function 0.114±0.002 LEP/SLC (e + e - ) Event shapes ± LHC/Tevatron (hh) Jets World average Combination of many measurements/techniques ±

Measuring the hadronic contribution to  e-e- e-e- e +,e - e-e- e-e-  e-e- e-e- ++

Summary Range of active and recent colliders – Large general purpose experiments – Small experiments tackling specific problems – Coherent program Each collision environment and collider energy makes a unique contribution to the study of the strong force pQCD remains to be falsified despite increasing precision and energy scale –  s (M z )  ±