Topics covered: Flavour Physics 2014

BaBar Physics book

• Lecture 1 (Feb 3):
  • History of particle physics: presentation by Frank Krauss (Durham U.)
  • A brief history of particle physics: presentation by S. L. Lloyd (Queen Mary, U. London)
• Lecture 2 (Feb 7):
  • PDG: Physical constants
  • PDG: Hadron naming scheme
• Lecture 3 (Feb 17):
  • PDG: Gauge boson and Higgs Calculation of widths and branching ratios of W and Z
• Lecture 4 (Feb 21):
  • PDG: quarks Types of quark masses: current, MS, MSbar, physical, constituent, ...
  • PDG: leptons Anomalous magnetic moments of electron and muon, muon decay rate and mass dependence, lifetime and branching ratios of tau
• Lecture 5 (Feb 24):
  • PDG: light mesons
  • G-parity and some applications
  • Calculation of [pi+] decay rate: decay constant [f_pi], dependence on lepton mass, helicity argument for lepton mass muppression, helicity vs chirality
  • Decay of pi0 through axial current anomaly, inverse dependence on [f_pi]
  • [eta-eta'] mixing, [rho], [phi], etc.
• Lecture 6 (Feb 28):
  • PDG: strange mesons
  • [tau-theta] puzzle, discovery of parity violation, pion decay experiment showing parity violation
  • Calculation of semileptonic decay [K+(e3)]: form factors [f+] and [f-], similarity with muon decay rate
  • Universality of weak coupling from semileptonic and leptonic decays, Cabibbo angle
  • [DeltaS = DeltaQ] rule: no FCNC
  • Calculation of [K0 -> mu+ mu-] decay rate through box diagram: quadratic divergence, smallness of BR implies very low cutoff
  • GIM mechanism: introduction of charmed quark, modification of the hadronic current, cancellation of quadratic divergences to get logarithmic ones, proportionality of GIM to [(m_c - m_u)^2/ MW^2], GIM suppression
  • ``Annihilation penguin'' diagrams that also contribute to [K0 -> mu+ mu-], gauge invariance of sum of all diagrams, the same GIM suppression
• Lecture 7 (Mar 3):
  • [K0 <-> K0bar] amplitude through two box diagrams, effective Hamiltonian as a 2x2 matrix, dispersive part [M] and absorptive part [i Gamma/2], relations among elements of [M] and [Gamma] due to CPT and CP, [K0-K0bar] mixing
  • CP conserving limit: observation of [K-Kbar] oscillations in semileptonic / flavour-specific decays, starting from a pure [K0]
  • CP properties of [K0], [K0bar], ``unphysical'' phase conventions, CP eigenvalues of CP eigenstates [K1], [K2], [pi pi], [pi pi pi]
  • Prediction of vanishing [K0(t) -> pi pi] at large [t] with CP conservation, discovery of CP violation
  • Calculation of [K0(t) -> pi pi] with CP violation, [KS] and [KL] as weak eigenstates, [eta] as the observable CP-violating quantity, direct vs indirect CP violation contributing to [eta]
• Lecture 8 (Mar 7):
  • Revision
• Lecture 9 (Mar 10):
  • Introducing CPV in mixing through [epsilon]
  • Direct CPV through the interference of two amplitudes, with different strong phases and different weak phases
  • Direct CPV in K decays parametrized by [epsilon'], corresponding to interference between the I=0 and I=2 channels
  • Relationship between [epsilon, epsilon'] and [eta+- , eta00]
  • Confirmation of direct CPV through measurements of [Re(epsilon'/epsilon)]
  • CPV in K system
• Assignment 1 (to be submitted Mar 24)
• Lecture 10 (Mar 14):
  • The CKM paradigm: writing the charged current Lagrangian in mass basis
  • Unitarity of the CKM matrix
  • Parameter counting leading to three angles and one complex phase of the CKM matrix
  • The Kobayashi-Maskawa paper
  • Talk about KM Nobel prize
• Lecture 11 (Mar 21):
  • Representation of the CKM matrix in terms of [theta12, theta23, theta13, deltaCP]
  • Expanding in powers of the Cabibbo angle: the Wolfenstein parametrization
  • Three unitarity triangles and their shapes
  • The angles [alpha, beta, gamma] of the ``fattest'' triangle
  • Jarlskog invariant, relation with magnitude of CPV and the areas of the unitarity triangles
• Lecture 12 (Mar 24):
  • CKM review in PDG
  • Magnitude of |Vud| from neutron / pion decay
  • Magnitude of |Vus| from [K] decay, and [tau -> K] decay
  • Magnitude of |Vcd| from semileptonic [D -> pi l nu] decays, or by double muon / single muon event ratio in neutrino beam experiments
  • Magnitude of |Vcs| from semileptonic [D -> K l nu] decays, or leptonic [Ds -> l nu] decays
• Lecture 13 (Mar 28):
  • Magnitude of |Vcb| from semileptonic [B -> D l nu] decays
  • Magnitude of |Vub| from semileptonic exclusive decays [B -> pi/rho l nu], semileptonic inclusice decays [b -> u l nu] endpoint spetrum, and the leptonic decay [B+ -> tau nu]
• Lecture 14 (Mar 31):
  • Magnitude of |Vtb Vtd| from [Delta Md] in [Bd-Bdbar] system
  • Magnitude of |Vtb Vts| from [Delta Ms] in [Bs-Bsbar] system
  • Expressions for [Delta Md] and [Delta Ms], cancellation of theoretical uncertainties in their ratio
  • Larger value of [Delta Ms] related to larger [Vts] as compared to [Vtd]
  • Putting bounds on the magnitudes of |Vtb|
• Lecture 15 (Apr 7):
  • Determination of [beta] from [Bd -> J/psi KS] decay
  • Allowing for direct CP violation: [S] and [C] parameters from the CP asymmetry [Acp] measured in [Bd -> J/psi KS]
  • Suppression of direct CPV, suppression of [Delta Gamma] makes the measurement clean
• Lecture 16 (Apr 11):
  • Determination of [gamma] from the interference between [B- -> D0 K-, D0 -> K+ pi-] and [B- -> D0bar K-, D0bar -> K+ pi-]
  • Choosing interfering modes such that the relative amplitudes are comparable
  • The ADS (Atwood-Dunietz-Soni) paper
• Lecture 17 (Apr 14):
  • Determining [alpha] from isospin relations in [B to pi pi] decays: the Gronau-London paper
  • Determining [alpha] from interference among [B -> rho pi, rho -> pi pi] states, Dalitz plot for [B -> pi+ pi- pi0]
  • Precision tests of the unitarity triangle through multiple measurements
  • Esimation of the angle [beta_s] of the flat unitarty triangle
  • Measurement of [beta_s] through [Bs to J/psi phi]: motivation
• Assignment 2 (to be submitted Apr 30)