PHZ 6358 "Standard Model I"
Class Diary for Fall 2015


Date Notes
Monday 8/24 First challenge. (invited lecturer: Dr. Doojin Kim)
Wednesday 8/26 Second challenge. (invited lecturer: Dr. Doojin Kim)
Friday 8/28 Third challenge. (invited lecturer: Dr. Doojin Kim)
Monday 8/31 Introductions, course and career objectives. Course policies, course web page. Using the arXiv. Using spires. Handout from the 2004 course at Cornell. MC4BSM workshop series. The writeup of the computer tutorials at Cornell.

Introduction to latex. To set up your latex environment, follow these instructions. The template discussed in class is located here. More about latex. Referencing: using bibtex or thebibliography. Introduction to Axodraw. See also jaxodraw. Figures and plots.

Wednesday 9/2 Overview of available tools.
Friday 9/4 No class.
Monday 9/7 No class: Labor Day
Wednesday 9/9 An overview of collider phenomenology.
Friday 9/11 Continue the overview of collider phenomenology. Branching fractions. Detector effects. Triggers. Acceptance and efficiencies. Simulating events at hadron colliders: parton level, fragmentation and hadronization, underlying event. Object reconstruction in a particle physics detector. Classification of reconstructed objects: electrons, muons, photons, jets, missing transverse momentum. Higgs production processes at LHC and Tevatron. Distinguishing signal from background.
Monday 9/14 The principle of Monte Carlo integration.
Wednesday 9/16 Cross-sections (chapter 4.5 in Peskin). Differential cross-section of a 2 to 2 process.
Friday 9/18 Types of particles and interactions in the Standard Model. Spin zero, 1/2 and 1. Gauge and Yukawa interactions. Higgs self-interactions. (Section 4.1 in Peskin + Chapter 1.)
Monday 9/21 Radiative corrections to high energy scattering processes. Real emissions and virtual (loop) corrections. Infrared and ultraviolet divergences. Cancellation of infrared divergences. (Brief overview of Chapter 6 in Peskin.) Newtonian mechanics: dependent and independent variables, action, Lagrangian, equations of motion.
Wednesday 9/23 Classical field theory. Klein-Gordon field and equation of motion. General formulation of Noether's theorem. Symmetries and conserved currents and charges.
Friday 9/25 Hamiltonian formulation. Applications of Noether's theorem. Energy conservation, momentum conservation. Phase rotation and charge conservation.
Monday 9/28 Quantization in field theory. Commutation relations among the fields. Creation and annihilation operators and their commutation relations. Number operator, Hamiltonian in terms of creation and annihilation operators.
Wednesday 9/30 Lorentz invariance of of the Lagrangian and the field equations for the scalar and electromagnetic field (chapter 3.1). Introduction to groups. Examples of finite (discrete) groups: Z2 (parity, time reversal, charge conjugation). Examples of continuous groups: O(2), SO(2), U(1), O(3) and SO(3).
Friday 10/2 The importance of generators. Algebra of the generators. The group SU(2). Representations of spatial rotations in terms of SU(2). The Lorentz group. Generators of rotations and boosts.
Monday 10/5 SU(2)xSU(2) structure of the Lorentz group. Algebra of A's and B's. (1/2,0) and (0,1/2) representations. Weyl spinors and their transformation properties (Section 3.2 in Peskin). Weyl equations. Dirac equation. Gamma matrices. P-slash notation.
Wednesday 10/7 Building Lorentz invariant objects out of Weyl spinors. Reality properties. Majorana spinors. The Dirac Lagrangian and its symmetries. Free particle solutions of the Dirac equation. u and v spinors. Spin sums. Quantization of the Dirac field. (Sections 3.3 and 3.5)
Friday 10/9 First midterm exam! Multiple choice, covers everything up to here.
Monday 10/12 Section 4.1: Interaction Lagrangians. Requirements. Dimensional analysis. Examples: phi fourth, Yukawa, QED. Gauge invariance. Covariant derivatives.
Wednesday 10/14 Section 4.2: Perturbation expansion of correlation functions. Section 4.3: Wick's theorem. Normal ordering and time ordering. Contractions. Section 4.4: Feynman diagrams. 2-point correlation function including interactions. Combinatorics of the first-order term. Symmetry factors.
Friday 10/16 Feynman rules for phi-fourth theory. Example of third-order terms. Feynman rules in momentum space. Momentum conservation at each vertex. Connected versus disconnected diagrams. Example of factorizing the vacuum bubbles: a 2-point function. Feynman rules: propagators, vertex factors.
Monday 10/19 Feynman rules for external fermions. Begin Chapter 5: Elementary processes of QED. Electron-positron annihilation into muon pairs. Spin sums and averaging. Trace technology of gamma matrices.
Wednesday 10/21 The answer for the differential cross-section for e+e- to mu+mu-. Rewrite it in terms of the scattering angle or the Mandelstam variables.
Friday 10/23 Discussion of singularities in the s, t and u-channels. Crossing symmetry. Electron-muon scattering. Compton scattering. Spin sums for photons.
Monday 10/26 Overview of CalcHEP. KC Kong's TASI webpage The SM particles and their quantum numbers. Interactions in the SM. Calculating a decay rate and branching fractions with CalcHEP. Decays and branching fractions of the Z boson.
Wednesday 10/28 Continue overview of CalcHEP. Setting up the initial state for cross-section calculations. Calculating cross-sections with CalcHEP and plotting distributions. Using Regularization for faster convergence.
Friday 10/30 CalcHEP installation tutorial. Higgs to 4 leptons at the LHC.
Monday 11/2 Continue overview of CalcHEP. Numerical precision on the cross section calculations. Single W production (W+ and W-) at the LHC. Comparing the contributions from different subprocesses. Imposing cuts.
Wednesday 11/4 Kinematic distributions in 2-body decays. Top quark decay. Kinematic distributions in 3-body decays.
Friday 11/6 Homecoming
Monday 11/9 Final CalcHEP tutorial. Discussion of the CalcHEP homework. Implementing a new model in CalcHEP: Z'. Implementing a user function in CalcHEP. Brief overview of CompHEP. Brief introduction to Madgraph
Wednesday 11/11 Veterans Day
Friday 11/13 Second midterm exam: CalcHEP team challenge.
Monday 11/16 Basic hadron collider kinematics. Reading: Section III and IV of Tao Han's TASI-04 lecture notes. Rapidity and pseudorapidity. Transverse momentum distribution of the leptons in W/Z decay. Jacobian peak.
Wednesday 11/18 Review of the CalcHEP team challenge. Transverse W mass. Dependence on the test invisible mass. A general introduction to minimized invariant mass variables can be found here.
Friday 11/20 Introduction to PYTHIA. The files which you need can be found here. PYTHIA installation and running our first example.
Monday 11/23 More fun with PYTHIA. Understanding the event output. Making plots. Reading the manual. Discussion of the homework: fourth generation. Turning on and off decay modes in pythia. Matrix elements versus parton showers. Detector simulation. The PYCELL routine in PYTHIA.
Wednesday 11/25 Thanksgiving
Friday 11/27 Thanksgiving
Monday 11/30 Group theory: fundamental and adjoint representation of SU(N). Color factors. Derivation of the gauge coupling RGEs.
Wednesday 12/2 Renormalization group equations of the Standard Model. Grand unification. RGEs in the SM, MSSM and NMSSM.
Friday 12/4 Higgs mechanism. Higgs potential. Higgs vacuum expectation value. Higgs self-interactions. RGE for the Higgs quartic coupling. Triviality and vacuum stability bounds (the Higgs chimney). Higgs boson couplings to gauge bosons: 2 gluons, 2 photons, Z-gamma, WW and ZZ. Teaching evaluations.
Monday 12/7 Self-interactions among the gauge bosons. Anomalous couplings. Mass spectrum of the gauge bosons. The breaking of SU(2)xU(1) down to QED. Z branching fractions. W branching fractions.
Wednesday 12/9 Final exam and solution key.

Some other things we did not get a chance to talk about this semester:

Special lecture: The Inevitability of Physical Laws: Why the Higgs Has to Exist Higgs cross-sections LHC Higgs Cross Section Working Group. Methods for measuring the masses of semi-invisibly decaying particles arXiv:1004.2732.
SUSY mass measurements in a long decay chain arXiv:0903.4371.
Transverse projections arXiv:1105.2977. MT2 variable hep-ph/9906349.
The MT2 "kink" arXiv:0709.0288.
Subsystem MT2 arXiv:0810.5576. MT2 in asymmetric cases arXiv:0911.4126.
MT2 crease arXiv:0908.3779.
MCT variable arXiv:0802.2879.
Decomposition within the transverse plane arXiv:0910.1584.
MT2perp and MT2 parallel arXiv:0910.3679. Meff variable hep-ph/0006276.
MT2 as a cut arXiv:0907.2713.
Smin variable arXiv:0812.1042.
Subsystem Smin variable arXiv:1006.0653.
The 3+1 dimensional analogues of MT2 arXiv:1212.1720 Combinatorics problem. Opposite flavor subtraction. Mixed event subtraction. II. Short decay chains: The Cambridge M_T2 variable. Example: 2-step decay chain. Subsystem MT2. Applications of MT and MT2 to event topologies with upstream momentum. Mass measurements from the MT2max kink. Doubly transverse projection: MT2perp. Discovering new physics in multijet events. The alpha_T variable. The S_min variable. Guest lecturer: Prof. Rick Field, Simulation of the underlying event in PYTHIA. Fermion mass generation: Yukawa interactions, fermion mass terms. CKM angles.