Cambridge University Press 978-1-107-03403-7 — Gauge Theories of Weak Decays Andrzej Buras Frontmatter More Information Gauge Theory of Weak Decays This is the first advanced, systematic, and comprehensive look at weak decays in the framework of gauge theories. Included is a large spectrum of topics, both theoretical and experimental. In addition to explicit advanced calculations of Feynman diagrams and the study of renormalization group strong interaction effects in weak decays, the book is devoted to the Standard Model Effective Field Theory, dominating present phenomenology in this field, and to new physics models with the goal of searching for new particles and interactions through quantum fluctuations. This book will benefit theorists, experimental researchers, and PhD students working on flavor physics and weak decays as well as physicists interested in physics beyond the Standard Model. In its concern for the search for new phenomena at short-distance scales through the interplay between theory and experiment, this book constitutes a travel guide to physics far beyond the scales explored by the Large Hadron Collider at CERN. Andrzej J. Buras is one of the most cited particle theorists in Europe and the most cited theoretical flavor physicist worldwide. He has written extensively on weak decays through lecture notes and review articles. He has been awarded the Smoluchowski-Warburg Medal of German and Polish Physics Societies, a Senior Carl von Linde Fellowship at TUM-IAS, an Advanced ERC Grant, and the 2020 Max Planck Medal. He is an ordinary member of the Bavarian Academy of Sciences and foreign member of two Academies in Poland. © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-1-107-03403-7 — Gauge Theories of Weak Decays Andrzej Buras Frontmatter More Information © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-1-107-03403-7 — Gauge Theories of Weak Decays Andrzej Buras Frontmatter More Information Gauge Theory of Weak Decays The Standard Model and the Expedition to New Physics Summits ANDRZEJ J. BURAS Technical University Munich © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-1-107-03403-7 — Gauge Theories of Weak Decays Andrzej Buras Frontmatter More Information University Printing House, Cambridge CB2 8BS, United Kingdom One Liberty Plaza, 20th Floor, New York, NY 10006, USA 477 Williamstown Road, Port Melbourne, VIC 3207, Australia 314–321, 3rd Floor, Plot 3, Splendor Forum, Jasola District Centre, New Delhi – 110025, India 79 Anson Road, #06–04/06, Singapore 079906 Cambridge University Press is part of the University of Cambridge. It furthers the University’s mission by disseminating knowledge in the pursuit of education, learning, and research at the highest international levels of excellence. www.cambridge.org Information on this title: www.cambridge.org/9781107034037 DOI: 10.1017/9781139524100 © Andrzej J. Buras 2020 This publication is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 2020 Printed in the United Kingdom by TJ International Ltd. Padstow Cornwall A catalogue record for this publication is available from the British Library. Library of Congress Cataloging-in-Publication Data Names: Buras, Andrzej J. (Andrzej Jerzy), 1946– author. Title: Gauge theory of weak decays : the standard model and the expedition to new physics summits / Andrzej J. Buras. Description: [New York, New York] : [Cambridge University Press], [2020] | Includes bibliographical references and index. Identifiers: LCCN 2019040866 (print) | LCCN 2019040867 (ebook) | ISBN 9781107034037 (hardback) | ISBN 9781139524100 (epub) Subjects: LCSH: Weak interactions (Nuclear physics) | Gauge fields (Physics) | Standard model (Nuclear physics) | Particles (Nuclear physics)–Flavor. | Mathematical physics. Classification: LCC QC794.8.W4 B84 2020 (print) | LCC QC794.8.W4 (ebook) | DDC 539.7/544–dc23 LC record available at https://lccn.loc.gov/2019040866 LC ebook record available at https://lccn.loc.gov/2019040867 ISBN 978-1-107-03403-7 Hardback Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party internet websites referred to in this publication and does not guarantee that any content on such websites is, or will remain, accurate or appropriate. © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-1-107-03403-7 — Gauge Theories of Weak Decays Andrzej Buras Frontmatter More Information To Gurli, Robert, Karin and Allan, Franziska and Ute Freya, Falk, Elisabeth, Inga and Janosch © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-1-107-03403-7 — Gauge Theories of Weak Decays Andrzej Buras Frontmatter More Information © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-1-107-03403-7 — Gauge Theories of Weak Decays Andrzej Buras Frontmatter More Information Contents Preface page xiii Acknowledgments xvi List of Abbreviations xviii Introduction 1 Grand View of the Standard Model 1 Grand View of New Physics 3 The Grand View of the Expedition and the Strategy 8 Introducing Main Players 17 How to Use This Book Optimally 20 Part I Basics of Gauge Theories 23 1 Fundamentals 25 1.1 Preliminaries 25 1.2 Lagrangians for Scalar Fields 26 1.3 First Encounter with Symmetries 27 1.4 Checking the Symmetries of Scalar Lagrangians 28 1.5 Promotion of a Global U(1) Symmetry to a Local U(1) Symmetry 29 1.6 A Closer Look at the U(1) Gauge Theory 30 1.7 Nonabelian Global Symmetries 32 1.8 Promotion of a Global Nonabelian Symmetry to a Local One 37 1.9 Lagrangians for Fermions 40 1.10 Spontaneous Symmetry Breakdown (SSB) 45 1.11 Higgs Mechanism 53 Part II The Standard Model 57 2 The Standard Model of Electroweak and Strong Interactions 59 2.1 Particle Content and Gauge Group of the SM 59 2.2 Short Overview: Lagrangian of the SM 60 2.3 Spontaneous Symmetry Breakdown in the SM 62 2.4 Gauge Boson Self-Interactions 65 2.5 Flavor Structure of the SM 66 2.6 Lepton Flavor Violation 79 vii © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-1-107-03403-7 — Gauge Theories of Weak Decays Andrzej Buras Frontmatter More Information viii Contents 2.7 Quantumchromodynamics (QCD) 80 2.8 Final Remarks 84 Part III Weak Decays in the Standard Model 85 3 Weak Decays at Tree Level 87 3.1 Muon Decay 87 3.2 Leptonic Decays of Charged Mesons 90 3.3 Semileptonic Decays of Charged Mesons 94 3.4 The Determination of |Vcb| and |Vub | 96 3.5 Leptonic and Semileptonic Decays of Neutral Mesons 98 3.6 Nonleptonic Decays of Mesons 98 3.7 Summary and Motivation 101 4 Technology beyond Trees 103 4.1 Loop Calculations 103 4.2 Renormalization 116 4.3 Renormalization Group Equations 123 5 Short-Distance Structure of Weak Decays 130 5.1 Operator Product Expansion in Weak Decays 130 5.2 Current-Current Operators beyond Leading Order 149 6 Efective Hamiltonians for FCNC Processes 179 6.1 Overture: General View of FCNC Processes 179 6.2 Calculations of Basic One-Loop Functions 189 6.3 ∆F = 2 Transitions 206 6.4 The World of Penguins 212 6.5 B → Xsγ Decay 229 6.6 b → sℓ+ℓ− and d → sℓ+ℓ− Transitions 244 6.7 d → sνν¯ and b → sνν¯ Transitions 249 7 Nonperturbative Methods in Weak Decays 253 7.1 General View 253 7.2 Dual QCD Approach 254 7.3 Lattice QCD Results 274 7.4 QCD Factorization for Exclusive B Decays 277 7.5 Heavy Quark Effective Theory (HQET) and Heavy Quark Expansions (HQE) 281 7.6 Other Nonperturbative Methods 282 8 Particle-Antiparticle Mixing and CP Violation in the Standard Model 283 8.1 Particle-Antiparticle Mixing 283 © in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-1-107-03403-7 — Gauge Theories of Weak Decays Andrzej Buras Frontmatter More Information ix Contents 8.2 Bq Decays into CP Eigenstates 299 8.3 Classification of CP Violation 304 8.4 Standard Analysis of the Unitarity Triangle (UT) 309 8.5 The Angles α, β,andγ from Bd,s Decays 317 8.6 B → πK Decays 325 9RareB and K Decays in the Standard Model 329 ∗ 9.1 B¯ → K¯ ℓ+ℓ− and B¯ → K¯ ℓ+ℓ− 329 + − + − + − 9.2 Bs,d → µ µ and Bs,d → τ τ , e e 347 + + 9.3 B → τ ντ 355 ∗ 9.4 B¯ → Dℓν¯l, B¯ → D ℓν¯l, Bc → J/ψℓν¯l,andΛb → Λcℓν¯l 357 + + 0 9.5 K → π νν¯ and KL → π νν¯ 367 ∗ 9.6 B → K νν¯, B → Kνν¯,andB → Xsνν¯ 375 + − 0 + − 9.7 KL,S → µ µ and KL → π ℓ ℓ 384 10 ε′/ε in the Standard Model 388 10.1 Preliminaries 388 10.2 Basic Formulas 390 10.3 Hadronic Matrix Elements 392 10.4 A Convenient Formula for ε′/ε in the SM 395 10.5 Numerical Analysis of ε′/ε 399 11 Charm Flavor Physics 402 11.1 Preliminaries 402 0 11.2 D0 − D¯ Mixing 402 11.3 CP Asymmetries in D Decays 404 11.4 Connection between D and K Physics 408 12 Status of Flavor Physics within the Standard Model 410 12.1 Successes 410 12.2 Summary of the Anomalies 410 12.3 Implications for the Wilson Coefficients 412 Part IV Weak Decays beyond the Standard Model 415 13 First Steps beyond the Standard Model 417 13.1 Preliminaries 417 13.2 ∆F = 2 Transitions 418 13.3 ∆F = 1 Nonleptonic Operators 427 14 Standard Model Efective Field Theory 433 14.1 Basic Framework 433 14.2 Full Set of Dimension-6 Operators 437 © in this web service Cambridge University Press www.cambridge.org Cambridge University