New Physics b Decays in Recommended Titles in Related Topics B Decays edited by Sheldon Stone ISBN: 978-981-02-0708-3 ISBN: 978-981-02-1330-5 (pbk) B Decays Revised Second Edition edited by Sheldon Stone ISBN: 978-981-02-1836-2 ISBN: 978-981-02-1897-3 (pbk) YYoonnggQQii -- 1122669966 -- NNeeww PPhhyyssiiccss iinn bb DDeeccaayyss..iinndddd 11 1177//33//22002222 1100::5577::2277 aamm New Physics b Decays in Marina Artuso Syracuse University, USA Gino Isidori University of Zurich, Switzerland Sheldon Stone Syracuse University, USA World Scientific NEW JERSEY • LONDON • SINGAPORE • BEIJING • SHANGHAI • HONG KONG • TAIPEI • CHENNAI • TOKYO Published by World Scientific Publishing Co. Pte. Ltd. 5 Toh Tuck Link, Singapore 596224 USA office: 27 Warren Street, Suite 401-402, Hackensack, NJ 07601 UK office: 57 Shelton Street, Covent Garden, London WC2H 9HE Library of Congress Cataloging-in-Publication Data Names: Stone, Sheldon, author. | Artuso, Marina, author. | Isidori, G. (Gino), author. Title: New physics in b decays / Sheldon Stone, Marina Artuso, Gino Isidori. Description: New Jersey : World Scientific, [2022] | Includes bibliographical references. Identifiers: LCCN 2021050571 (print) | LCCN 2021050572 (ebook) | ISBN 9789811251290 (hardcover) | ISBN 9789811251306 (ebook for institutions) | ISBN 9789811251313 (ebook for individuals) Subjects: LCSH: Beta decay. | CP violation (Nuclear physics) | Standard model (Nuclear physics) Classification: LCC QC793.5.B425 S76 2022 (print) | LCC QC793.5.B425 (ebook) | DDC 539.7/523--dc23/eng/20211201 LC record available at https://lccn.loc.gov/2021050571 LC ebook record available at https://lccn.loc.gov/2021050572 British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library. Copyright © 2022 by World Scientific Publishing Co. Pte. Ltd. All rights reserved. This book, or parts thereof, may not be reproduced in any form or by any means, electronic or mechanical, including photocopying, recording or any information storage and retrieval system now known or to be invented, without written permission from the publisher. For photocopying of material in this volume, please pay a copying fee through the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, USA. In this case permission to photocopy is not required from the publisher. For any available supplementary material, please visit https://www.worldscientific.com/worldscibooks/10.1142/12696#t=suppl Typeset by Stallion Press Email: [email protected] Printed in Singapore YYoonnggQQii -- 1122669966 -- NNeeww PPhhyyssiiccss iinn bb DDeeccaayyss..iinndddd 22 1177//33//22002222 1100::5577::2277 aamm March21,2022 15:25 NewPhysicsinbDecays-9inx6in b4532-fm pagev Acknowledgments Marina Artuso and Sheldon Stone thank the U. S. National Science FoundationandSyracuseUniversityforsupport.GinoIsidoriacknowledges the support of the Swiss National Science Foundation, the European Research Council, and the University of Zurich. We all thank many flavor physics oriented theorists and experimentalists for interesting and useful conversations,and numerous collaborations.Marina Artuso thanks Robert Bernstein and Alexey Petrov for the useful conversations in the shared effort in the current U.S. particle physics community planning study. Gino Isidori is particularly grateful to Riccardo Barbieri, Javier Fuentes- Martin, Admir Greljo, Davide Marzocca, and Nicola Serra, whose critical comments and constructive discussions have contributed to shape many of the ideas presented in chapter 4. Special thanks go to Marzia Bordone, Claudia Cornella, and Phillip Urquijo for reading and commenting on the manuscript. Finally we would like to thank Marcello Rotondo for communications on HFLAV averages, Marcella Bona for help with UTfit averages,andJeromeCharlesandStephaneMonteil forhelponCKMfitter and CKMlive. v B1948 Governing Asia TTTThhhhiiiissss ppppaaaaggggeeee iiiinnnntttteeeennnnttttiiiioooonnnnaaaallllllllyyyy lllleeeefffftttt bbbbllllaaaannnnkkkk BB11994488__11--AAookkii..iinndddd 66 99//2222//22001144 44::2244::5577 PPMM March21,2022 15:25 NewPhysicsinbDecays-9inx6in b4532-fm pagevii Preface At the time of publication one of the authors of this book, Sheldon Stone, will not be here to see the last fruit of his labor published. His coauthors wouldliketodedicatethisbooktohismemoryandtosharewiththereaders the passion and vibrancy that he brought to this project. Throughout his career, Sheldon was always relentlessly seeking man- ifestations of new physics in b decays. This was pursued through the developmentofnewdetectortechnologiesincalorimetry,trackingorhadron identification,andviadifferentexperimentalapproaches.Afterpioneeringb physicsatelectro-positroncolliders,withthe CLEOexperimentatCornell, he played a major role in the development of b physics experiments at hadron machines, demonstrating the high potential of this apparently hos- tileenvironmentinunveilingalargelyunexploredb-hadronphenomenology. In parallel,he wasconstantly involvedinthe explorationof new signatures and new analysis techniques. The bookoriginatesfromanidea ofSheldon. Excitingresults challeng- ingourunderstandingoffundamentalphysicshaveemergedfromb-physics experimentsinthelastfewyears.Hefeltitwasimportanttodiscussthemin a thorough but also accessible way, both experimentally and theoretically. These results are critically analyzed with a healthy skepticism, but also the growing awareness that they could represent a turning point in our understanding of the laws of Nature. Their implications for the future of this field are also discussed. Writing this book has been a unique experience: it was an honor to work with a scientist with the drive, knowledge, and wit, characteristic of Sheldon. It was a privilege to share this journey with him, and we are grateful for the wonderful collaboration that we developed along the way. Marina Artuso and Gino Isidori vii B1948 Governing Asia TTTThhhhiiiissss ppppaaaaggggeeee iiiinnnntttteeeennnnttttiiiioooonnnnaaaallllllllyyyy lllleeeefffftttt bbbbllllaaaannnnkkkk BB11994488__11--AAookkii..iinndddd 66 99//2222//22001144 44::2244::5577 PPMM March21,2022 15:25 NewPhysicsinbDecays-9inx6in b4532-fm pageix Contents Acknowledgments v Preface vii 1 Introduction 1 1.1 The Standard Model and its open problems . . . . . . . . . . 1 1.1.1 The flavor structure of the SM and the CKM matrix . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2 A first overview of b physics . . . . . . . . . . . . . . . . . . . 7 1.2.1 Searching for NP in b decays . . . . . . . . . . . . . . 10 1.3 Experimental aspects . . . . . . . . . . . . . . . . . . . . . . . . 11 1.4 Theoretical tools . . . . . . . . . . . . . . . . . . . . . . . . . . 16 1.4.1 Some properties of the CKM matrix . . . . . . . . . 16 1.4.2 Low-energy effective Lagrangians . . . . . . . . . . . 19 1.4.3 Hadronic matrix elements . . . . . . . . . . . . . . . . 22 1.4.4 Effective Lagrangiansfor physics beyond the SM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1.4.5 Accidental and approximate symmetries . . . . . . 27 2 Traditional New Physics searches 30 2.1 Determining the size of the CKM elements . . . . . . . . . 30 2.1.1 Measurements of |Vcb| . . . . . . . . . . . . . . . . . . 30 2.1.2 Measurements of |Vub| . . . . . . . . . . . . . . . . . . 35 2.1.3 The composition of the inclusive semileptonics bottom to charm branching fractions . . . . . . . . 39 2.2 The measurement of γ . . . . . . . . . . . . . . . . . . . . . . . 40 ix