Lecture Notes in Physics Kazunori Hanagaki Junichi Tanaka Makoto Tomoto Yuji Yamazaki Experimental Techniques in Modern High- Energy Physics A Beginner’s Guide Lecture Notes in Physics FoundingEditors WolfBeiglböck JürgenEhlers KlausHepp Hans-ArwedWeidenmüller Volume 1001 SeriesEditors RobertaCitro,Salerno,Italy PeterHänggi,Augsburg,Germany MortenHjorth-Jensen,Oslo,Norway MaciejLewenstein,Barcelona,Spain AngelRubio,Hamburg,Germany WolfgangSchleich,Ulm,Germany StefanTheisen,Potsdam,Germany JamesD.Wells,AnnArbor,MI,USA GaryP.Zank,Huntsville,AL,USA The series Lecture Notes in Physics (LNP), founded in 1969, reports new developmentsinphysicsresearchandteaching-quicklyandinformally,butwitha highqualityandtheexplicitaimtosummarizeandcommunicatecurrentknowledge in an accessible way. 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Proposals should be sent to a member of the Editorial Board, or directly to the responsible editor at Springer: Dr Lisa Scalone [email protected] Kazunori Hanagaki · Junichi Tanaka · Makoto Tomoto · Yuji Yamazaki Experimental Techniques in Modern High-Energy Physics A Beginner‘s Guide KazunoriHanagaki JunichiTanaka InstituteofParticleandNuclearStudies InternationalCenterforElementaryParticle KEK Physics Ibaraki,Japan TheUniversityofTokyo Tokyo,Japan MakotoTomoto InstituteofParticleandNuclearStudies YujiYamazaki KEK DepartmentofPhysics Ibaraki,Japan KobeUniversity Kobe,Japan DepartmentofPhysics NagoyaUniversity Nagoya,Japan ThisworkwassupportedbySponsoringConsortiumforOpenAccessPublishinginParticle Physics. ISSN0075-8450 ISSN1616-6361 (electronic) LectureNotesinPhysics ISBN978-4-431-56929-9 ISBN978-4-431-56931-2 (eBook) https://doi.org/10.1007/978-4-431-56931-2 ©TheEditor(s)(ifapplicable)andTheAuthor(s)2022.Thisbookisanopenaccesspublication. OpenAccessThisbookislicensedunderthetermsoftheCreativeCommonsAttribution4.0International License(http://creativecommons.org/licenses/by/4.0/),whichpermitsuse,sharing,adaptation,distribu- tionandreproductioninanymediumorformat,aslongasyougiveappropriatecredittotheoriginal author(s)andthesource,providealinktotheCreativeCommonslicenseandindicateifchangeswere made. Theimagesorotherthirdpartymaterialinthisbookareincludedinthebook’sCreativeCommonslicense, unlessindicatedotherwiseinacreditlinetothematerial.Ifmaterialisnotincludedinthebook’sCreative Commonslicenseandyourintendeduseisnotpermittedbystatutoryregulationorexceedsthepermitted use,youwillneedtoobtainpermissiondirectlyfromthecopyrightholder. Theuseofgeneraldescriptivenames,registerednames,trademarks,servicemarks,etc.inthispublication doesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevant protectivelawsandregulationsandthereforefreeforgeneraluse. Thepublisher,theauthors,andtheeditorsaresafetoassumethattheadviceandinformationinthisbook arebelievedtobetrueandaccurateatthedateofpublication.Neitherthepublishernortheauthorsor theeditorsgiveawarranty,expressedorimplied,withrespecttothematerialcontainedhereinorforany errorsoromissionsthatmayhavebeenmade.Thepublisherremainsneutralwithregardtojurisdictional claimsinpublishedmapsandinstitutionalaffiliations. ThisSpringerimprintispublishedbytheregisteredcompanySpringerJapanKK,partofSpringerNature. The registered company address is: Shiroyama Trust Tower, 4-3-1 Toranomon, Minato-ku, Tokyo 105-6005,Japan Preface This book is meant to be a practical introduction to data analysis in high- energy physics experiments, especially collider experiments using high-energy accelerators. The field requires a very wide range of knowledge, not only for the theoretical particle physics but also for the detector technology and computing science. We often find beginners in this field suffering from understanding how data analysis is taking place, simply because of too many things one needs to know. Reading journalpapersoftendoesnothelpsincecomprehensiveunderstandingandtraining are required, which are not described in the papers themselves. It is quite difficult to obtain such skills unless you do once a data analysis by yourself. We hope that this book helps reduce such difficulties by providing a one-stop “explanation” on key aspects of data analysis. This book should also serve as an introductory textbook for those who are learning about individual subjects in data analysis, such as • Basic idea on methods to reconstruct and identify particles; • Detector calibration in collider experiments; • Statistical methods used in collider experiments; • Methods to increase sensitivities of an experiment through data analysis techniques; • Simulation of particle collisions and detector responses. This book is intended for undergraduate and first-year graduate students who have taken basic-level courses in particle physics. Throughout the book, we tried toexplainwhathappenswithoutexplicitlyusingmanyequations.Weneithercover theformalismontheinteractionofparticlesinmatternorthetheoryoftheparticle v vi Preface physics Standard Model. Instead, we, experimental physicists, provide a “prac- tical” explanation of how to understand after considering those formalism and theories. Tsukuba, Japan Kazunori Hanagaki Tokyo, Japan Junichi Tanaka Nagoya/Tsukuba, Japan Makoto Tomoto Kobe, Japan Yuji Yamazaki October 2021 Acknowledgments We thank Springer for giving us a chance to publish this book. We greatly appre- ciateSpringer’seditorsfortheirpatience.Thestartofwritingthisbookisbackin 2015whenparticlephysicistsbaskedintheafterglowofthediscoveryoftheHiggs boson. Since then our writing was so slow, but the editors kept us encouraging to go on. Without their endless efforts, this book would not be realised. Wethankourfamiliesfortheircontinuoussupportnotonlyinwritingthisbook but also the physicists’ life. Tsukuba, Japan Kazunori Hanagaki Tokyo, Japan Junichi Tanaka Nagoya/Tsukuba, Japan Makoto Tomoto Kobe, Japan Yuji Yamazaki October 2021 vii Contents 1 Introduction ......................................................... 1 2 BasicIdeaofMeasurementsinParticleCollisions ................... 7 2.1 Observables of Particle Scattering ............................... 7 2.2 Cross Section and Luminosity ................................... 9 2.3 Identifying Processes Through Measurements of Final State Particles ......................................................... 11 2.4 Event Acceptance and Efficiency ................................ 14 2.5 Nature of Hadron-Hadron Collisions and Kinematic Variables .... 15 2.6 Structure of Hadrons and Parton Density Function ............... 18 References ........................................................... 20 3 Apparatus ........................................................... 21 3.1 Particle Collisions at High Energies .............................. 21 3.2 Accelerator ...................................................... 22 3.3 Detector ......................................................... 24 3.3.1 Particle Interaction with Material ......................... 25 3.3.2 ATLAS Detector ......................................... 26 3.3.3 Trigger ................................................... 29 3.3.4 Optimisation of Detector Performance .................... 34 References ........................................................... 34 4 Statistics ............................................................. 35 4.1 Uncertainty ..................................................... 36 4.1.1 Statistical Uncertainty .................................... 36 4.1.2 Systematic Uncertainty ................................... 36 4.2 Probability Distribution .......................................... 37 4.2.1 Basics of Probability Distributions ........................ 38 4.2.2 Binomial Distribution .................................... 39 4.2.3 Poisson Distribution ...................................... 40 4.2.4 Normal Distribution (Gaussian Distribution) .............. 41 4.2.5 Uniform Distribution ..................................... 42 4.2.6 Breit-Wigner Distribution ................................ 44 ix