Bayesian analysis at work troublesome examples J. Charles, A. Hoecker, H. LackerandF. Le Diberder
Outline • Setting the stage • Frequentist analysis • Bayesian analysis • Simplified stage • Concerns and Conclusion
Setting the Stage B decays into ππ final states 6 observables And 6 theoretical unknown 6 decay amplitudes are involved CP Violation α
Bayesian Analysis Data α • Theoretical parameters: • arerandomvariables • - following known PDF mind
QuantumMechanics parameterization 6 decay amplitudes are involved Onephase may be set to zero Bayesian (I) frequentist
Standard model parameterization The 6 amplitudes are split into two kind of contributions Trees & Penguins 10^9 Bayesian (II) amplitudes & phases … or real & Imaginary parts ? Bayesian (II) frequentist Bayesian (III)
Changingdecay channel (ρρ) Bayesian (I) Bayesian (II) !?! Quantum Mechanics amplitudes & phases JHEP 0507:028,2005 frequentist (I)(II)(II) real & imaginary parts Bayesian (III)
B → ππ Taking key experimental information away removing all experimental hints related toα amplitudes & phases Quantum Mechanics
Conclusion … that attractive ? priors parameterization
Spheres within a cube Simplified Stage 6 Dspace Bayesian treatment one knows nothing about the individual space componentsx,y,z… What do we known about the radius r =√(x^2+y^2+…) ?
Concerns& Conclusion α CKM Should we ?