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Measurement Of The Top Quark Coupling To The Z Boson And Applications To Searches For Physics Beyond The Standard Model
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Book Synopsis Measurement of the Top Quark Coupling to the Z Boson, and Applications to Searches for Physics Beyond the Standard Model by : Baptiste Ravina
Download or read book Measurement of the Top Quark Coupling to the Z Boson, and Applications to Searches for Physics Beyond the Standard Model written by Baptiste Ravina and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Measurements and Searches with Top Quarks by :
Download or read book Measurements and Searches with Top Quarks written by and published by . This book was released on 2008 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1995 the last missing member of the known families of quarks, the top quark, was discovered by the CDF and D0 experiments at the Tevatron, a proton-antiproton collider at Fermilab near Chicago. Until today, the Tevatron is the only place where top quarks can be produced. The determination of top quark production and properties is crucial to understand the Standard Model of particle physics and beyond. The most striking property of the top quark is its mass--of the order of the mass of a gold atom and close to the electroweak scale--making the top quark not only interesting in itself but also as a window to new physics. Due to the high mass, much higher than of any other known fermion, it is expected that the top quark plays an important role in electroweak symmetry breaking, which is the most prominent candidate to explain the mass of particles. In the Standard Model, electroweak symmetry breaking is induced by one Higgs field, producing one additional physical particle, the Higgs boson. Although various searches have been performed, for example at the Large Electron Positron Collider (LEP), no evidence for the Higgs boson could yet be found in any experiment. At the Tevatron, multiple searches for the last missing particle of the Standard Model are ongoing with ever higher statistics and improved analysis techniques. The exclusion or verification of the Higgs boson can only be achieved by combining many techniques and many final states and production mechanisms. As part of this thesis, the search for Higgs bosons produced in association with a top quark pair (t{bar t}H) has been performed. This channel is especially interesting for the understanding of the coupling between Higgs and the top quark. Even though the Standard Model Higgs boson is an attractive candidate, there is no reason to believe that the electroweak symmetry breaking is induced by only one Higgs field. In many models more than one Higgs boson are expected to exist, opening even more channels to search for charged or neutral Higgs bosons. Depending on its mass, the charged Higgs boson is expected to decay either into top quarks or be the decay product of a top quark. For masses below the top quark mass, the top decay into a charged Higgs boson and a b quark can occur at a certain rate, additionally to the decays into W bosons and a b quark. The different decays of W and charged Higgs bosons can lead to deviations of the observed final number of events in certain final states with respect to the Standard Model expectation. A global search for charged Higgs bosons in top quark pair events is presented in this thesis, resulting in the most stringent limits to-date. Besides the decay of top quarks into charged Higgs or W bosons, new physics can also show up in the quark part of the decay. While in the Standard Model the top quark decays with a rate of about 100% into a W boson and a b quark, there are models where the top quark can decay into a W boson and a non-b quark. The ratio of branching fractions in which the top quark decays into a b quark over the branching fractions in which the top quark decays into all quarks is measured as part of this thesis, yielding the most precise measurement today. Furthermore, the Standard Model top quark pair production cross section is essential to be known precisely since the top quark pair production is the main background for t{bar t}H production and many other Higgs and beyond the Standard Model searches. However, not only the search or the test of the Standard Model itself make the precise measurement of the top quark pair production cross section interesting. As the cross section is calculated with high accuracy in perturbative QCD, a comparison of the measurement to the theory expectation yields the possibility to extract the top quark mass from the cross section measurement. Although many dedicated techniques exist to measure the top quark mass, the extraction from the cross section represents an important complementary measurement. The latter is briefly discussed in this thesis and compared to direct top mass measurements. The goal of this thesis is the improved understanding of the top quark sector and its use as a window to new physics. Techniques are extended and developed to measure the top quark pair production cross section simultaneously with the ratio of branching fractions, the t{bar t}H cross section or the rate with which top quarks decay into charged Higgs bosons. Some of the results are then taken to extract more information. The cross section measurement is used to extract the top quark mass, and the ratio of the top quark pair production cross sections in different final states, yielding a limit on non-Standard Model top quark decays.
Download or read book Erratum to written by and published by . This book was released on 2015 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: We study top quark pair production in association with a Z boson at the Large Hadron Collider (LHC) and investigate the prospects of measuring the couplings of top quarks to the Z boson. To date these couplings have not been constrained in direct measurements. Such a determination will be possible for the first time at the LHC. Our calculation improves previous coupling studies through the inclusion of next-to-leading order (NLO) QCD corrections in production and decays of all unstable particles. We treat top quarks in the narrow-width approximation and retain all NLO spin correlations. To determine the sensitivity of a coupling measurement we perform a binned log-likelihood ratio test based on normalization and shape information of the angle between the leptons from the Z boson decay. The obtained limits account for statistical uncertainties as well as leading theoretical systematics from residual scale dependence and parton distribution functions. We use current CMS data to place the first direct constraints on the ttbZ couplings. We also consider the upcoming high-energy LHC run and find that with 300 inverse fb of data at an energy of 13 TeV the vector and axial ttbZ couplings can be constrained at the 95% confidence level to C_V=0.24^{+0.39}_{-0.85} and C_A=-0.60^{+0.14}_{-0.18}, where the central values are the Standard Model predictions. This is a reduction of uncertainties by 25% and 42%, respectively, compared to an analysis based on leading-order predictions. We also translate these results into limits on dimension-six operators contributing to the ttbZ interactions beyond the Standard Model.
Book Synopsis Measurement of the Top Quark Mass in the Dilepton Final State Using the Matrix Element Method by : Alexander Grohsjean
Download or read book Measurement of the Top Quark Mass in the Dilepton Final State Using the Matrix Element Method written by Alexander Grohsjean and published by Springer Science & Business Media. This book was released on 2010-10-01 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main pacemakers of scienti?c research are curiosity, ingenuity, and a pinch of persistence. Equipped with these characteristics a young researcher will be s- cessful in pushing scienti?c discoveries. And there is still a lot to discover and to understand. In the course of understanding the origin and structure of matter it is now known that all matter is made up of six types of quarks. Each of these carry a different mass. But neither are the particular mass values understood nor is it known why elementary particles carry mass at all. One could perhaps accept some small generic mass value for every quark, but nature has decided differently. Two quarks are extremely light, three more have a somewhat typical mass value, but one quark is extremely massive. It is the top quark, the heaviest quark and even the heaviest elementary particle that we know, carrying a mass as large as the mass of three iron nuclei. Even though there exists no explanation of why different particle types carry certain masses, the internal consistency of the currently best theory—the standard model of particle physics—yields a relation between the masses of the top quark, the so-called W boson, and the yet unobserved Higgs particle. Therefore, when one assumes validity of the model, it is even possible to take precise measurements of the top quark mass to predict the mass of the Higgs (and potentially other yet unobserved) particles.
Book Synopsis Search for Standard Model Top Quark and Z Boson Associated Production at ATLAS by : Bradley D. Schoenrock
Download or read book Search for Standard Model Top Quark and Z Boson Associated Production at ATLAS written by Bradley D. Schoenrock and published by . This book was released on 2016 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Searches for New Quarks and Leptons in Z Boson Decays by :
Download or read book Searches for New Quarks and Leptons in Z Boson Decays written by and published by . This book was released on 1990 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Top Quark as a Window to Beyond the Standard Model Physics by :
Download or read book The Top Quark as a Window to Beyond the Standard Model Physics written by and published by . This book was released on 2013 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark was the last of the Standard Model quarks to be discovered, and is of considerable interest. The closeness of the top quark mass to the electroweak scale is suggestive that the top quark could be closely related to the mechanisms for electroweak symmetry breaking. Any new physics in electroweak symmetry breaking models could then preferentially couple to the top quark, making the top quark a promising probe for new physics. In this thesis, we will explore two aspects of the top quark as a harbinger to new physics: the top forward-backward asymmetry as seen at the Tevatron and the search for stops. In this thesis, we will discuss the Asymmetric Left-Right Model (ALRM), a model that is based on the gauge group $U'(1)\times SU(2)\times SU'(2)$ with couplings $g_1\̂prime, g_2\̂prime,$ and $g'$ associated with the fields $B',W,W'$, respectively, and show how this model can explain the top forward-backward asymmetry. We will then explore the scalar sector of the ALRM, and provide a specific Higgs mechanism that provides the masses for the $W'$ and $Z'$ bosons. The top forward-backward asymmetry is a test of invariance of charge-conjugation. Thus, we look at the $X$-gluon model, a model that was motivated by the top forward-backward asymmetry, and show that one can look at the longitudinal polarization of the top-quark to test parity conservation. Finally, we investigate searches for stop squarks, the supersymmetric partner of the top quark, at the Large Hadron Collider (LHC) using shape-based analyses.
Book Synopsis Measurements of the Top Quark Mass and Decay Width with the D0 Detector by :
Download or read book Measurements of the Top Quark Mass and Decay Width with the D0 Detector written by and published by . This book was released on 2011 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark discovery in 1995 at Fermilab is one of the major proofs of the standard model (SM). Due to its unique place in SM, the top quark is an important particle for testing the theory and probing for new physics. This article presents most recent measurements of top quark properties from the D0 detector. In particular, the measurement of the top quark mass, the top antitop mass difference and the top quark decay width. The discovery of the top quark in 1995 confirmed the existence of a third generation of quarks predicted in the standard model (SM). Being the heaviest elementary particle known, the top quark appears to become an important particle in our understanding of the standard model and physics beyond it. Because of its large mass the top quark has a very short lifetime, much shorter than the hadronization time. The predicted lifetime is only 3.3 · 10−25s. Top quark is the only quark whose properties can be studied in isolation. A Lorentz-invariant local Quantum Field Theory, the standard model is expected to conserve CP. Due to its unique properties, the top quark provides a perfect test of CPT invariance in the standard model. An ability to look at the quark before being hadronized allows to measure directly mass of the top quark and its antiquark. An observation of a mass difference between particle and antiparticle would indicate violation of CPT invariance. Top quark through its radiative loop correction to the W mass constrains the mass of the Higgs boson. A precise measurement of the top quark mass provides useful information to the search of Higgs boson by constraining its region of possible masses. Another interesting aspect is that the top quark's Yukawa coupling to the Higgs boson is very close to unity (0.996 ± 0.006). That implies it may play a special role in the electroweak symmetry breaking mechanism.
Book Synopsis Measurement of the Associated Production of a Vector Boson (W, Z) and Top Quark Pair in the Opposite Sign Dilepton Channel with Pp Collisions at √s by :
Download or read book Measurement of the Associated Production of a Vector Boson (W, Z) and Top Quark Pair in the Opposite Sign Dilepton Channel with Pp Collisions at √s written by and published by . This book was released on 2014 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: The heaviest known elementary particle predicted by the Standard Model (SM), the top quark, was discovered in 1995 by the CDF and D0 collaborations. The large top quark mass translates into a coupling to the Higgs boson close to unity and, therefore, it is expected that the top quark may play a special role in electroweak symmetry breaking. Among its various properties, the study of the coupling between the top quark and the Z-boson would allow to test the SM prediction, and search for any deviations caused by possible new physics signals. The first step towards the measurement of such a co...
Book Synopsis Search for Associated Production of a Z Boson with a Single Top Quark and for TZ Flavour-changing Interactions in Pp Collisions at $\sqrt{s}$ by :
Download or read book Search for Associated Production of a Z Boson with a Single Top Quark and for TZ Flavour-changing Interactions in Pp Collisions at $\sqrt{s}$ written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for the production of a single top quark in association with a Z boson is presented, both to identify the expected standard model process and to search for flavour-changing neutral current interactions. The data sample corresponds to an integrated luminosity of 19.7 inverse-femtobarns recorded by the CMS experiment at the LHC in proton-proton collisions at $\sqrt{s}$ = 8 TeV. Final states with three leptons (electrons or muons) and at least one jet are investigated. An events yield compatible with tZq standard model production is observed, and the corresponding cross section is measured to be sigma(p p -> t Z q -> l nu b l+ l- q) = 10 +8/-7 fb with a significance of 2.4 standard deviations. No presence of flavour-changing neutral current production of tZq is observed. Exclusion limits at 95% confidence level on the branching fractions of a top quark decaying to a Z boson and an up or a charm quark are found to be B(t -> Z u) 0.022% and B(t - Z c)
Book Synopsis Beyond Standard Model Collider Phenomenology of Higgs Physics and Supersymmetry by : Marc Christopher Thomas
Download or read book Beyond Standard Model Collider Phenomenology of Higgs Physics and Supersymmetry written by Marc Christopher Thomas and published by Springer. This book was released on 2016-08-01 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis studies collider phenomenology of physics beyond the Standard Model at the Large Hadron Collider (LHC). It also explores in detail advanced topics related to Higgs boson and supersymmetry – one of the most exciting and well-motivated streams in particle physics. In particular, it finds a very large enhancement of multiple Higgs boson production in vector-boson scattering when Higgs couplings to gauge bosons differ from those predicted by the Standard Model. The thesis demonstrates that due to the loss of unitarity, the very large enhancement for triple Higgs boson production takes place. This is a truly novel finding. The thesis also studies the effects of supersymmetric partners of top and bottom quarks on the Higgs production and decay at the LHC, pointing for the first time to non-universal alterations for two main production processes of the Higgs boson at the LHC–vector boson fusion and gluon–gluon fusion. Continuing the exploration of Higgs boson and supersymmetry at the LHC, the thesis extends existing experimental analysis and shows that for a single decay channel the mass of the top quark superpartner below 175 GeV can be completely excluded, which in turn excludes electroweak baryogenesis in the Minimal Supersymmetric Model. This is a major new finding for the HEP community. This thesis is very clearly written and the introduction and conclusions are accessible to a wide spectrum of readers.
Book Synopsis Search for Flavor-Changing Neutral Current Top Quark Decays t → Hq, with H → bb̅ , in pp Collisions at √s = 8 TeV with the ATLAS Detector by : Shota Tsiskaridze
Download or read book Search for Flavor-Changing Neutral Current Top Quark Decays t → Hq, with H → bb̅ , in pp Collisions at √s = 8 TeV with the ATLAS Detector written by Shota Tsiskaridze and published by Springer. This book was released on 2017-08-02 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD thesis focuses on the search for flavor-changing neutral currents in the decay of a top quark to an up-type quark (q = u, c) and the Standard Model Higgs boson, where the Higgs boson decays to bb. Further, the thesis presents the combination of this search for top quark pair events with other ATLAS searches – in the course of which the most restrictive bounds to date on tqH interactions were obtained. Following on from the discovery of the Higgs boson, it is particularly important to measure the Yukawa couplings of the Standard Model fermions; these parameters may provide crucial insights to help solve the flavor puzzle and may help reveal the presence of new physics before it is directly observed in experiments.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 1052 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.
Book Synopsis The Search for Supersymmetry in Hadronic Final States Using Boosted Object Reconstruction by : Giordon Holtsberg Stark
Download or read book The Search for Supersymmetry in Hadronic Final States Using Boosted Object Reconstruction written by Giordon Holtsberg Stark and published by . This book was released on 2018 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Large Hadron Collider (LHC) operates at the highest energy scales ever artificially created in particle collision experiments with a center-of-mass energy √s = 13 TeV. In addition, the high luminosity allows the unique opportunity to probe the Standard Model at the electroweak scale and explore for rare signs of new physics beyond the Standard Model. The coupling of the third-generation top quark to the Higgs boson introduces large, quadratic, radiative corrections to the Higgs mass, requiring a significant amount of fine-tuning that results in a nearly perfect correction of the Higgs mass from the Planck scale to the observable electroweak scale. A possible solution to the naturalness problem proposes a collection of supersymmetric partners to the Standard Model particles with the mass of lightest particles at the electroweak scale: the gluino, the stop squarks, and the lightest supersymmetric particle. This thesis presents the results of a search for gluino pair production decaying via stop squarks to the lightest neutralino in hadronic final states using a total integrated luminosity 36.1 fb‒1 of data collected with the ATLAS detector in 2015 and 2016. This analysis considers a simplified supersymmetry model targeting extreme regions of the phase space with large missing transverse momentum, multiple b-tagged jets, and several energetic jets. No excess is observed and limits on the gluino mass are set at the 95% CL, greatly extending the previous results in 2012 from 1.4 TeV to 1.9 TeV. The increase of the LHC luminosity also poses challenges to the current trigger system in the ATLAS detector necessitating planned upgrades. One of the upgrades for the trigger system is the Global Feature Extractor (gFEX) which aims to recover lost efficiency in boosted hadronic final states by identifying large radius jets produced by top quarks, Higgs, Z and W bosons which are critical for future ATLAS physics programs. This module is a unique board with 3 processor FPGAs for data processing and an embedded multi-processor system-on-chip for slow-control and monitoring. This thesis will also describe the work on developing this hardware and several physics upgrade studies on the trigger performance.
Download or read book Properties of the Top Quark written by and published by . This book was released on 2009 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of particle physics is the understanding of elementary particles and their interactions. The current theory of elementary particle physics, the Standard Model, contains twelve different types of fermions which (neglecting gravity) interact through the gauge bosons of three forces. In addition a scalar particle, the Higgs boson, is needed for theoretical consistency. These few building blocks explain all experimental results found in the context of particle physics, so far. Nevertheless, it is believed that the Standard Model is only an approximation to a more complete theory. First of all the fourth known force, gravity, has withstood all attempts to be included until now. Furthermore, the Standard Model describes several features of the elementary particles like the existence of three families of fermions or the quantisation of charges, but does not explain these properties from underlying principles. Finally, the lightness of the Higgs boson needed to explain the symmetry breaking is difficult to maintain in the presence of expected corrections from gravity at high scales. This is the so called hierarchy problem. In addition astrophysical results indicate that the universe consists only to a very small fraction of matter described by the Standard Model. Large fractions of dark energy and dark matter are needed to describe the observations. Both do not have any correspondence in the Standard Model. Also the very small asymmetry between matter and anti-matter that results in the observed universe built of matter (and not of anti-matter) cannot be explained until now. It is thus an important task of experimental particle physics to test the predictions of the Standard Model to the best possible accuracy and to search for deviations pointing to necessary extensions or modifications of our current theoretical understanding. The top quark was predicted to exist by the Standard Model as the partner of the bottom quark. It was first observed in 1995 by the Tevatron experiments CDF and D0 and was the last of the quarks to be discovered. As the partner of the bottom quark the top quark is expected to have quantum numbers identical to that of the other known up-type quarks. Only the mass is a free parameter. We now know that it is more than 30 times heavier than the next heaviest quark, the bottom quark. Thus, within the Standard Model all production and decay properties are fully defined. Having the complete set of quarks further allows to verify constraints that the Standard Model puts on the sum of all quarks or particles. This alone is reason enough to experimentally study the top quark properties. The high value of the top quark mass and its closeness to the electroweak scale has inspired people to speculate that the top quark could have a special role in the electroweak symmetry breaking. Confirming the expected properties of the top quark experimentally establishes the top quark as we expect it to be. Any deviation from the expectations gives hints to new physics that may help to solve the outstanding questions. In this review the recent results on top quark properties obtained by the Tevatron experiments CDF and D0 are summarized. At the advent of the LHC special emphasis is given to the basic measurement methods and the dominating systematic uncertainties. After a short introduction to the Standard Model and the experimental environment in the remainder of this chapter, Chapter 2 describes the current status of top quark mass measurements. Then measurments of interaction properties are described in Chapter 3. Finally, Chapter 4 deals with analyses that consider hypothetical particles beyond the Standard Model in the observed events.
Book Synopsis Measurement of the W Boson Helicity in Top-antitop Quark Events with the CDF II Experiment by : Thorsten Chwalek
Download or read book Measurement of the W Boson Helicity in Top-antitop Quark Events with the CDF II Experiment written by Thorsten Chwalek and published by . This book was released on 2006 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1995 the top quark was discovered at the Tevatron proton-antiproton collider at Fermilab by the CDF and D0 collaborations [1, 2]. It is the most massive known elementary particle and its mass is currently measured with a precision of about 1.3% [3, 4]. However, the measurements of several other top quark properties are still statistically limited, so the question remains whether the Standard Model of elementary particle physics successfully predicts these properties. This thesis addresses one interesting aspect of top quark decay, the helicity of the produced W boson. Until the start of the Large Hadron Collider (LHC) at CERN, the Tevatron with a center-of-mass energy of {radical}s = 1.96 TeV is the only collider, where top quarks can be produced. In the Standard Model the top quark decays predominantly into a W boson and a b quark, with a branching ratio close to 100%. The V-A structure of the weak interaction of the Standard Model predicts that the W{sup +} bosons from the top quark decay t {yields} W{sup +}b are dominantly either longitudinally polarized or left handed, while right handed W bosons are heavily suppressed and even forbidden in the limit of a massless b quark. Under the assumption of a massless b quark, for a top quark mass of 173 GeV/c{sup 2} the Standard Model predicts the fraction F0 of longitudinally polarized W bosons to be 0.7 and 0.3 for the fraction F{_} of left handed W bosons, while the fraction F{sub +} of right handed W bosons is predicted to be zero. Since next-to-leading order corrections change these fractions only slightly, a significant deviation from the predicted value for F{sub 0} or a nonzero value for F{sub +} could indicate new physics. Left-right symmetric models [5], for example, lead to a significant right handed fraction of W bosons in top decays. Such a right handed component (V+A coupling) would lead to a smaller left handed fraction, while F{sub 0} would remain unchanged. Since the decay rate to longitudinal W bosons depends on the Yukawa coupling of the top quarks, the measurement of F{sub 0} is sensitive to the mechanism of electroweak symmetry breaking. Alternative models can lead to an altered F{sub 0} fraction. In this analysis the W helicity fractions are measured in a selected sample rich in t{bar B} events where one lepton, at least four jets, and missing transverse energy are required. All kinematic quantities describing the t{bar t} decay are determined. As a sensitive observable, we use the cosine of the decay angle {theta}*, which is defined as the angle between the momentum of the charged lepton in the W boson rest frame and the W boson momentum in the top quark rest frame. The data used in this analysis were taken with the Collider Detector at Fermilab (CDF II) in the years 2002-2006 and correspond to an integrated luminosity of about 955 pb{sup -1}. Previous CDF measurements of the W boson helicity fractions in top quark decays used either the square of the invariant mass of the charged lepton and the b quark jet, M{sub {ell}b}{sup 2}, or the lepton p{sub T} distribution as a discriminant. The D0 collaboration used a matrix-element method to extract a value of F{sub 0}; in a second analysis the reconstructed distribution of cos {theta}* was utilized to measure F{sub +}. CDF gives the latest value of F{sub 0} = 0.74{sub -0.34}{sup +0.22}, while D measured F{sub 0} = 0.56 {+-} 0.31. The CDF collaboration also gives the current upper limit of F{sub +}
Book Synopsis Looking Inside Jets by : Simone Marzani
Download or read book Looking Inside Jets written by Simone Marzani and published by Springer. This book was released on 2019-05-11 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: This concise primer reviews the latest developments in the field of jets. Jets are collinear sprays of hadrons produced in very high-energy collisions, e.g. at the LHC or at a future hadron collider. They are essential to and ubiquitous in experimental analyses, making their study crucial. At present LHC energies and beyond, massive particles around the electroweak scale are frequently produced with transverse momenta that are much larger than their mass, i.e., boosted. The decay products of such boosted massive objects tend to occupy only a relatively small and confined area of the detector and are observed as a single jet. Jets hence arise from many different sources and it is important to be able to distinguish the rare events with boosted resonances from the large backgrounds originating from Quantum Chromodynamics (QCD). This requires familiarity with the internal properties of jets, such as their different radiation patterns, a field broadly known as jet substructure. This set of notes begins by providing a phenomenological motivation, explaining why the study of jets and their substructure is of particular importance for the current and future program of the LHC, followed by a brief but insightful introduction to QCD and to hadron-collider phenomenology. The next section introduces jets as complex objects constructed from a sequential recombination algorithm. In this context some experimental aspects are also reviewed. Since jet substructure calculations are multi-scale problems that call for all-order treatments (resummations), the bases of such calculations are discussed for simple jet quantities. With these QCD and jet physics ingredients in hand, readers can then dig into jet substructure itself. Accordingly, these notes first highlight the main concepts behind substructure techniques and introduce a list of the main jet substructure tools that have been used over the past decade. Analytic calculations are then provided for several families of tools, the goal being to identify their key characteristics. In closing, the book provides an overview of LHC searches and measurements where jet substructure techniques are used, reviews the main take-home messages, and outlines future perspectives.
