The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,283 new measurements from 899 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as heavy neutrinos, supersymmetric and technicolor particles, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Supersymmetry, Extra Dimensions, Particle Detectors, Probability, and Statistics. Among the 112 reviews are many that are new or heavily revised including those on: Dark Energy, Higgs Boson Physics, Electroweak Model, Neutrino Cross Section Measurements, Monte Carlo Neutrino Generators, Top Quark, Dark Matter, Dynamical Electroweak Symmetry Breaking, Accelerator Physics of Colliders, High-Energy Collider Parameters, Big Bang Nucleosynthesis, Astrophysical Constants and Cosmological Parameters. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov . Contents Abstract, Contributors, Highlights and Table of Contents Acrobat PDF (4.4 MB) Introduction Acrobat PDF (595 KB) Particle Physics Summary Tables Gauge and Higgs bosons Acrobat PDF (204 KB) Leptons Acrobat PDF (167 KB) Quarks Acrobat PDF (115 KB) Mesons Acrobat PDF (976 KB) Baryons Acrobat PDF (384 KB) Searches (Supersymmetry, Compositeness, etc.) Acrobat PDF (120 KB) Tests of conservation laws Acrobat PDF (383 KB) Reviews, Tables, and Plots Detailed contents for this section Acrobat PDF (73 KB) Constants, Units, Atomic and Nuclear Properties Acrobat PDF (395 KB) Standard Model and Related Topics Acrobat PDF (8.37 MB) Astrophysics and Cosmology Acrobat PDF (3.79 MB) Experimental Methods and Colliders Acrobat PDF (3.82 MB) Mathematical Tools of Statistics, Monte Carlo, Group Theory Acrobat PDF (1.77 MB) Kinematics, Cross-Section Formulae, and Plots
Full general relativity is almost certainly ‘chaotic’. We argue that this entails a notion of non-integrability: a generic general relativistic model, at least when coupled to cosmologically interesting matter, likely possesses neither differentiable Dirac observables nor a reduced phase space. It follows that the standard notion of observable has to be extended to include non-differentiable or even discontinuous generalized observables. These cannot carry Poisson-algebraic structures and do not admit a standard quantization; one thus faces a quantum representation problem of gravitational observables. This has deep consequences for a quantum theory of gravity, which we investigate in a simple model for a system with Hamiltonian constraint that fails to be completely integrable. We show that basing the quantization on standard topology precludes a semiclassical limit and can even prohibit any solutions to the quantum constraints. Our proposed solution to this problem is to refine topology such that a complete set of Dirac observables becomes continuous. In the toy model, it turns out that a refinement to a polymer-type topology, as e.g. used in loop gravity, is sufficient. Basing quantization of the toy model on this finer topology, we find a complete set of quantum Dirac observables and a suitable semiclassical limit. This strategy is applicable to realistic candidate theories of quantum gravity and thereby suggests a solution to a long-standing problem which implies ramifications for the very concept of quantization. Our work reveals a qualitatively novel facet of chaos in physics and opens up a new avenue of research on chaos in gravity which hints at deep insights into the structure of quantum gravity.
