Written by world-leading experts in particle physics, this new book from Luciano Maiani and Omar Benhar, with contributions from the late Nicola Cabibbo, is based on Feynman's path integrals. Key elements of gauge theories are described—Feynman diagrams, gauge-fixing, Faddeev-Popov ghosts—as well as renormalization in Quantum Electrodynamics. Quarks and QCD interactions are introduced. Renormalization group and high momentum behaviour of the coupling constants is discussed in QED and QCD, with asymptotic freedom derived at one-loop. These concepts are related to the Higgs boson and models of grand unification. "… an excellent introduction to the quantum theory of gauge fields and their applications to particle physics. … It will be an excellent book for the serious student and a good reference for the professional practitioner. Let me add that, scattered through the pages, we can find occasional traces of Nicola Cabibbo's style."—John Iliopoulos, CNRS-Ecole Normale Supérieure " … The volume ends with an illuminating description of the expectation generated by the recent discovery of the Higgs boson, combined with the lack of evidence for super-symmetric particles in the mass range 0.6-1 TeV."—Arturo Menchaca-Rocha, FinstP, Professor of Physics, Mexico's National Autonomous University, Former President of the Mexican Academy of Sciences, Presidential Advisor "…The reader is masterfully guided through the subtleties of the quantum field theory and elementary particle physics from simple examples in Quantum Mechanics to salient details of modern theory."—Mikhail Voloshin, Professor of Physics, University of Minnesota

Abstract The NA48/2 experiment at CERN reports the first observation of the K± → π0π0μ±ν decay based on a sample of 2437 candidates with 15% background contamination collected in 2003–2004. The decay branching ratio in the kinematic region of the squared dilepton mass above 0.03 GeV2/c4 is measured to be (0.65 ± 0.03) × 10−6. The extrapolation to the full kinematic space, using a specific model, is found to be (3.45 ± 0.16) × 10−6, in agreement with chiral perturbation theory predictions.

The NA48/2 experiment at CERN reports the first observation of the [Formula: see text] decay from an exposure of [Formula: see text] charged kaon decays recorded in 2003–2004. A sample of 4919 candidates with 4.9% background contamination allows the determination of the branching ratio in the full kinematic region. The study of the kinematic space shows evidence for a structure-dependent contribution in agreement with predictions based on chiral perturbation theory. Several [Formula: see text]- and [Formula: see text]-violating asymmetries are also evaluated. The most precise measurement of the charged kaon semi-leptonic form factors obtained by NA48/2 with 4.4 million [Formula: see text] and 2.3 million [Formula: see text] events collected in 2004 will also be presented.

The NA48/2 experiment at CERN reports the first observation of the K ± → π ± π 0 e + e − decay from an exposure of 1 . 7 × 10 11 charged kaon decays recorded in 2003–2004. A sample of 4919 candidates with 4.9% background contamination allows the determination of the branching ratio in the full kinematic region, BR ( K ± → π ± π 0 e + e − ) = ( 4 . 24 ± 0 . 14 ) × 10 − 6 . The study of the kinematic space shows evidence for a structure dependent contribution in agreement with predictions based on chiral perturbation theory. Several P- and CP-violating asymmetries are also evaluated.

The NA48/2 experiment at CERN reports the first observation of the K-+/- -> pi(+/-)pi(0)e(+)e(-) decay from an exposure of 1.7 x 10(11) charged kaon decays recorded in 2003-2004. A sample of 4919 candidates with 4.9% background contamination allows the determination of the branching ratio in the full kinematic region, BR(K-+/- -> pi(+/-)pi(0)e(+)e(-)) = (4.24 +/- 0.14) x 10(-6). The study of the kinematic space shows evidence for a structure dependent contribution in agreement with predictions based on chiral perturbation theory. Several P- and CP-violating asymmetries are also evaluated. (C) 2018 The Author(s). Published by Elsevier B.V.

A bstract A measurement of the form factors of charged kaon semileptonic decays is presented, based on 4.4 × 10 6 K ± → π 0 e ± ν e ( K e 3 ± ) and 2.3 × 10 6 K ± → π 0 μ ± ν μ ( K μ 3 ± ) decays collected in 2004 by the NA48/2 experiment. The results are obtained with improved precision as compared to earlier measurements. The combination of measurements in the K e 3 ± and K μ 3 ± modes is also presented.

The NA48/2 experiment collected data in 2003 and 2004 with the main purpose to study direct CP violation in charged kaons decaying in three pions. Thanks to the huge statistics collected, other studies are also possible. In this paper two recent results, in the framework of QCD studies, are reported: the measurement of the K± → π0e±ν Form Factors and the first observation of the rare decay K± → π±π0e+e−.