Search for: All records

Abstract The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,143 new measurements from 709 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 supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 120 reviews are many that are new or heavily revised, including a new review on Machine Learning, and one on Spectroscopy of Light Meson Resonances. The Review is divided into two volumes. Volume 1 includes the Summary Tables and 97 review articles. Volume 2 consists of the Particle Listings and contains also 23 reviews that address specific aspects of the data presented in the Listings. The complete Review (both volumes) is published online on the website of the Particle Data Group (pdg.lbl.gov) and in a journal. Volume 1 is available in print as the PDG Book. A Particle Physics Booklet with the Summary Tables and essential tables, figures, and equations from selected review articles is available in print, as a web version optimized for use on phones, and as an Android app. 

Abstract The interaction of $$\textrm{K}^{-}$$ K - with protons is characterised by the presence of several coupled channels, systems like $${\overline{\textrm{K}}}^0$$ K ¯ 0 n and $$\uppi \Sigma $$ π Σ with a similar mass and the same quantum numbers as the $$\textrm{K}^{-}$$ K - p state. The strengths of these couplings to the $$\textrm{K}^{-}$$ K - p system are of crucial importance for the understanding of the nature of the $$\Lambda (1405)$$ Λ ( 1405 ) resonance and of the attractive $$\textrm{K}^{-}$$ K - p strong interaction. In this article, we present measurements of the $$\textrm{K}^{-}$$ K - p correlation functions in relative momentum space obtained in pp collisions at $$\sqrt{s}~=~13$$ s = 13  Te, in p–Pb collisions at $$\sqrt{s_{\textrm{NN}}}~=~5.02$$ s NN = 5.02  Te, and (semi)peripheral Pb–Pb collisions at $$\sqrt{s_{\textrm{NN}}}~=~5.02$$ s NN = 5.02  Te. The emitting source size, composed of a core radius anchored to the $$\textrm{K}^{+}$$ K + p correlation and of a resonance halo specific to each particle pair, varies between 1 and 2 fm in these collision systems. The strength and the effects of the $${\overline{\textrm{K}}}^0$$ K ¯ 0 n and $$\uppi \Sigma $$ π Σ inelastic channels on the measured $$\textrm{K}^{-}$$ K - p correlation function are investigated in the different colliding systems by comparing the data with state-of-the-art models of chiral potentials. A novel approach to determine the conversion weights $$\omega $$ ω , necessary to quantify the amount of produced inelastic channels in the correlation function, is presented. In this method, particle yields are estimated from thermal model predictions, and their kinematic distribution from blast-wave fits to measured data. The comparison of chiral potentials to the measured $$\textrm{K}^{-}$$ K - p interaction indicates that, while the $$\uppi \Sigma $$ π Σ – $$\textrm{K}^{-}$$ K - p dynamics is well reproduced by the model, the coupling to the $${\overline{\textrm{K}}}^0$$ K ¯ 0 n channel in the model is currently underestimated. 

Abstract The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,324 new measurements from 878 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 supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 120 reviews are many that are new or heavily revised, including a new review on High Energy Soft QCD and Diffraction and one on the Determination of CKM Angles from B Hadrons. The Review is divided into two volumes. Volume 1 includes the Summary Tables and 98 review articles. Volume 2 consists of the Particle Listings and contains also 22 reviews that address specific aspects of the data presented in the Listings. The complete Review (both volumes) is published online on the website of the Particle Data Group (pdg.lbl.gov) and in a journal. Volume 1 is available in print as the PDG Book. A Particle Physics Booklet with the Summary Tables and essential tables, figures, and equations from selected review articles is available in print and as a web version optimized for use on phones as well as an Android app.