Search for Heavy Higgs Bosons in Lepton + Jets Final States with the ATLAS Detector at the Large Hadron Collider

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ISBN 13 :
Total Pages : 208 pages
Book Rating : 4.:/5 (13 download)

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Book Synopsis Search for Heavy Higgs Bosons in Lepton + Jets Final States with the ATLAS Detector at the Large Hadron Collider by : 張漢龍

Download or read book Search for Heavy Higgs Bosons in Lepton + Jets Final States with the ATLAS Detector at the Large Hadron Collider written by 張漢龍 and published by . This book was released on 2017 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Search for Weak Gaugino Production in Final States With One Lepton, Two B-Jets Consistent With a Higgs Boson, and Missing Transverse Momentum With the ATLAS Detector

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (932 download)

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Book Synopsis Search for Weak Gaugino Production in Final States With One Lepton, Two B-Jets Consistent With a Higgs Boson, and Missing Transverse Momentum With the ATLAS Detector by : Andy Yen

Download or read book Search for Weak Gaugino Production in Final States With One Lepton, Two B-Jets Consistent With a Higgs Boson, and Missing Transverse Momentum With the ATLAS Detector written by Andy Yen and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ATLAS detector at the Large Hadron Collider is a discovery machine that is able to probe into the multi-TeV scale and search for physics beyond the Standard Model. This thesis presents a search for chargino and neutralino production in final states with one lepton, two b-jets, and missing transverse momentum, consistent with R-parity conserving supersymmetric scenarios. The analysis is based on 20.3 fb -1 of sqrt(s) = 8 TeV proton-proton collision data recorded with the ATLAS detector. Observations are found to be consistent with the Standard Model expectations and 95% confidence level limits are obtained in the context of both simplified supersymmetric models and phenomenological Minimal Supersymmetric Standard Models.

Search for New Physics in Mono-jet Final States in pp Collisions

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Publisher : Springer
ISBN 13 : 3319588710
Total Pages : 245 pages
Book Rating : 4.3/5 (195 download)

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Book Synopsis Search for New Physics in Mono-jet Final States in pp Collisions by : Giuliano Gustavino

Download or read book Search for New Physics in Mono-jet Final States in pp Collisions written by Giuliano Gustavino and published by Springer. This book was released on 2017-06-19 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis provides a detailed and comprehensive description of the search for New Physics at the Large Hadron Collider (LHC) in the mono-jet final state, using the first 3.2 fb-1 of data collected at the centre of mass energy of colliding protons of 13~TeV recorded in the ATLAS experiment at LHC. The results are interpreted as limits in different theoretical contexts such as compressed supersymmetric models, theories that foresee extra-spatial dimensions and in the dark matter scenario. In the latter the limits are then compared with those obtained by other ATLAS analyses and by experiments based on completely different experimental techniques, highlighting the role of the mono-jet results in the context of dark matter searches.Lastly, a set of possible analysis improvements are proposed to reduce the main uncertainties that affect the signal region and to increase the discovery potential by further exploiting the information on the final state.

Theoretical Studies on Extended Higgs Sectors Towards Future Precision Measurements

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Publisher : Springer Nature
ISBN 13 : 9819913241
Total Pages : 268 pages
Book Rating : 4.8/5 (199 download)

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Book Synopsis Theoretical Studies on Extended Higgs Sectors Towards Future Precision Measurements by : Masashi Aiko

Download or read book Theoretical Studies on Extended Higgs Sectors Towards Future Precision Measurements written by Masashi Aiko and published by Springer Nature. This book was released on 2023-05-20 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book investigates the physics of the discovered Higgs boson and additional Higgs bosons in the extended Higgs models which includes higher-order quantum corrections. While the 125 GeV Higgs boson was discovered, the structure of the Higgs sector is still a mystery. Since the Higgs sector determines the concrete realization of the Higgs mechanism, the study of its nature is one of the central interests in current and future high-energy physics. The book begins with a review of the standard model and the two-Higgs doublet model, which is one of the representatives of the extended Higgs models. Subsequently, we discuss the studies of the two-Higgs doublet model at the lowest order of perturbation. Following the lowest-order analysis, we study the higher-order electroweak corrections in Higgs physics. After reviewing the renormalization procedure and the higher-order corrections in the decays of the discovered Higgs boson, we discuss the higher-order corrections in the Higgs strahlung process from an electron-positron collision, the decays of the additional charged and CP-odd Higgs bosons in the two-Higgs doublet model. From the series of these studies, it is found that the nature of the Higgs sector can be widely investigated by future collider experiments.

Search for New Phenomena in Top-Antitop Quarks Final States with Additional Heavy-Flavour Jets with the ATLAS Detector

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Publisher : Springer Nature
ISBN 13 : 9811509328
Total Pages : 279 pages
Book Rating : 4.8/5 (115 download)

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Book Synopsis Search for New Phenomena in Top-Antitop Quarks Final States with Additional Heavy-Flavour Jets with the ATLAS Detector by : Daiki Yamaguchi

Download or read book Search for New Phenomena in Top-Antitop Quarks Final States with Additional Heavy-Flavour Jets with the ATLAS Detector written by Daiki Yamaguchi and published by Springer Nature. This book was released on 2019-10-30 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on the search for a new heavy particle, the Vector-Like Top quark (VLT), in the Large Hadron Collider (LHC) at CERN. The signal process is the pair production of VLT decaying into a Higgs boson and top quark (TT→Ht+X, X=Ht, Wb, Zt). The signal events result in top–antitop quarks final states with additional heavy flavour jets. The book summarises the analysis of the data collected with the ATLAS detector in 2015 and 2016. In order to better differentiate between signals and backgrounds, exclusive taggers of top quark and Higgs boson were developed and optimised for VLT signals. These efforts improved the sensitivity by roughly 30%, compared to the previous analysis. The analysis outcomes yield the strongest constraints on parameter space in various BSM theoretical models. In addition, the book addresses detector operation and the evaluation of tracking performance. These efforts are essential to properly collecting dense events and improving the accuracy of the reconstructed objects that are used for particle identification. As such, they represent a valuable contribution to data analysis in extremely dense environments.

Search for the Associated Production of the Higgs Boson with a Top Quark Pair in Multilepton Final States with the ATLAS Detector

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ISBN 13 :
Total Pages : 23 pages
Book Rating : 4.:/5 (925 download)

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Book Synopsis Search for the Associated Production of the Higgs Boson with a Top Quark Pair in Multilepton Final States with the ATLAS Detector by :

Download or read book Search for the Associated Production of the Higgs Boson with a Top Quark Pair in Multilepton Final States with the ATLAS Detector written by and published by . This book was released on 2015 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Advances in Jet Substructure at the LHC

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Publisher : Springer Nature
ISBN 13 : 3030728587
Total Pages : 287 pages
Book Rating : 4.0/5 (37 download)

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Book Synopsis Advances in Jet Substructure at the LHC by : Roman Kogler

Download or read book Advances in Jet Substructure at the LHC written by Roman Kogler and published by Springer Nature. This book was released on 2021-05-10 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the reader to the field of jet substructure, starting from the basic considerations for capturing decays of boosted particles in individual jets, to explaining state-of-the-art techniques. Jet substructure methods have become ubiquitous in data analyses at the LHC, with diverse applications stemming from the abundance of jets in proton-proton collisions, the presence of pileup and multiple interactions, and the need to reconstruct and identify decays of highly-Lorentz boosted particles. The last decade has seen a vast increase in our knowledge of all aspects of the field, with a proliferation of new jet substructure algorithms, calculations and measurements which are presented in this book. Recent developments and algorithms are described and put into the larger experimental context. Their usefulness and application are shown in many demonstrative examples and the phenomenological and experimental effects influencing their performance are discussed. A comprehensive overview is given of measurements and searches for new phenomena performed by the ATLAS and CMS Collaborations. This book shows the impressive versatility of jet substructure methods at the LHC.

Theory And Phenomenology Of Sparticles: An Account Of Four-dimensional N=1 Supersymmetry In High Energy Physics

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Publisher : World Scientific
ISBN 13 : 9814495344
Total Pages : 582 pages
Book Rating : 4.8/5 (144 download)

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Book Synopsis Theory And Phenomenology Of Sparticles: An Account Of Four-dimensional N=1 Supersymmetry In High Energy Physics by : Manuel Drees

Download or read book Theory And Phenomenology Of Sparticles: An Account Of Four-dimensional N=1 Supersymmetry In High Energy Physics written by Manuel Drees and published by World Scientific. This book was released on 2005-01-18 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supersymmetry or SUSY, one of the most beautiful recent ideas of physics, predicts sparticles existing as superpartners of particles. This book gives a theoretical and phenomenological account of sparticles. Starting from a basic level, it provides a comprehensive, pedagogical and user-friendly treatment of the subject of four-dimensional N=1 supersymmetry as well as its observational aspects in high energy physics and cosmology. Part One of the book introduces the requisite formal theory, preceded by a discussion of the naturalness problem. Part Two describes the supersymmetrization of the Standard Model of particle interactions as well as the origin of soft supersymmetry breaking and how it can be mediated from higher energies. Search strategies for sparticles, supersymmetric Higgs bosons, nonminimal scenarios and cosmological implications are some of the other topics covered. Novel features of the book include a dictionary between two-component and four-component spinor notation, a step-by-step derivation of the nonrenormalization theorem, an extended discussion of supersymmetric renormalization group evolution, detailed analyses of minimal and nonminimal models with gravity (including anomaly) mediated and gauge mediated supersymmetry breaking as well as elaborate self-contained presentations of collider signals of sparticles plus supersymmetric Higgs bosons and of supersymmetric cosmology. Appendices list all Feynman rules for the vertices of the Minimal Supersymmetric Standard Model.

Heavy Higgs Boson Search in the Four Lepton Decay Channel with the ATLAS Detector

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (11 download)

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Book Synopsis Heavy Higgs Boson Search in the Four Lepton Decay Channel with the ATLAS Detector by : Denys Denysiuk

Download or read book Heavy Higgs Boson Search in the Four Lepton Decay Channel with the ATLAS Detector written by Denys Denysiuk and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis is focused on the heavy Higgs boson search in four lepton decay channelwith Run-2 data from the ATLAS detector at the Large Hadron Collider. The analysis publishedat ICHEP 2016 conference that is based on 14.8 fb-1 of 13 TeV data is described in details, whilethe updated results that include 36.1 fb-1 of 13 TeV data are shown as well. The heavy Higgssearch is carried out in a model independent way and it is covering different signal widthhypotheses: narrow width approximation that assumes the signal natural width to be negligiblecomparing to the detector resolution, and the large width assumption including an effect of theinterference with the Standard Model backgrounds. The search that benefits from additionalkinematic discriminant under the scalar signal assumption is presented as well. Thismodification allows to increase the analysis sensitivity up to 25%.The thesis also discusses an upgrade of the ATLAS Muons Spectrometer, namely the NewSmall Wheel project. In particular, simulation of the cavern background that will affect theupgraded detector and commissioning of the Micromegas modules produced at CEA-Saclay forthe New Small Wheel are described.

A Search for Displaced Leptons in the ATLAS Detector

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Publisher : Springer Nature
ISBN 13 : 3030916723
Total Pages : 146 pages
Book Rating : 4.0/5 (39 download)

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Book Synopsis A Search for Displaced Leptons in the ATLAS Detector by : Lesya Horyn

Download or read book A Search for Displaced Leptons in the ATLAS Detector written by Lesya Horyn and published by Springer Nature. This book was released on 2022-02-07 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a search for long-lived particles decaying into displaced electrons and/or muons with large impact parameters. This signature provides unique sensitivity to the production of theoretical lepton-partners, sleptons. These particles are a feature of supersymmetric theories, which seek to address unanswered questions in nature. The signature searched for in this thesis is difficult to identify, and in fact, this is the first time it has been probed at the Large Hadron Collider (LHC). It covers a long-standing gap in coverage of possible new physics signatures. This thesis describes the special reconstruction and identification algorithms used to select leptons with large impact parameters and the details of the background estimation. The results are consistent with background, so limits on slepton masses and lifetimes in this model are calculated at 95% CL, drastically improving on the previous best limits from the Large Electron Positron Collider (LEP).

Search for the Standard Model Higgs Boson in the H → ZZ → l + l - qq Decay Channel at CMS

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Publisher : Springer Science & Business Media
ISBN 13 : 3319009036
Total Pages : 137 pages
Book Rating : 4.3/5 (19 download)

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Book Synopsis Search for the Standard Model Higgs Boson in the H → ZZ → l + l - qq Decay Channel at CMS by : Francesco Pandolfi

Download or read book Search for the Standard Model Higgs Boson in the H → ZZ → l + l - qq Decay Channel at CMS written by Francesco Pandolfi and published by Springer Science & Business Media. This book was released on 2013-08-15 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: The theoretical foundations of the Standard Model of elementary particles relies on the existence of the Higgs boson, a particle which has been revealed for the first time by the experiments run at the Large Hadron Collider (LHC) in 2012. As the Higgs boson is an unstable particle, its search strategies were based on its decay products. In this thesis, Francesco Pandolfi conducted a search for the Higgs boson in the H → ZZ → l + l - qq Decay Channel with 4.6 fb -1 of 7 TeV proton-proton collision data collected by the Compact Muon Solenoid (CMS) experiment. The presence of jets in the final state poses a series of challenges to the experimenter: both from a technical point of view, as jets are complex objects and necessitate of ad-hoc reconstruction techniques, and from an analytical one, as backgrounds with jets are copious at hadron colliders, therefore analyses must obtain high degrees of background rejection in order to achieve competitive sensitivity. This is accomplished by following two directives: the use of an angular likelihood discriminant, capable of discriminating events likely to originate from the decay of a scalar boson from non-resonant backgrounds, and by using jet parton flavor tagging, selecting jets compatible with quark hadronization and discarding jets more likely to be initiated by gluons. The events passing the selection requirements in 4.6 fb -1 of data collected by the CMS detector are examined, in the search of a possible signal compatible with the decay of a heavy Higgs boson. The thesis describes the statistical tools and the results of this analysis. This work is a paradigm for studies of the Higgs boson with final states with jets. The non-expert physicists will enjoy a complete and eminently readable description of a proton-proton collider analysis. At the same time, the expert reader will learn the details of the searches done with jets at CMS.

Search for Heavy Down-Type Vector-Like Quarks in the Lepton-Plus-Jets Final State in 8 TeV Proton-proton Collisions Using the ATLAS Detector at the LHC

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (95 download)

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Book Synopsis Search for Heavy Down-Type Vector-Like Quarks in the Lepton-Plus-Jets Final State in 8 TeV Proton-proton Collisions Using the ATLAS Detector at the LHC by : Diedi Hu

Download or read book Search for Heavy Down-Type Vector-Like Quarks in the Lepton-Plus-Jets Final State in 8 TeV Proton-proton Collisions Using the ATLAS Detector at the LHC written by Diedi Hu and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the chiral B scenario with a 100% branching ratio of the decay B->Wt, the observed (expected) 95% CL lower limit on the B mass is 814 GeV (756 GeV).

Weak Scale Supersymmetry

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Publisher : Cambridge University Press
ISBN 13 : 1009289845
Total Pages : 557 pages
Book Rating : 4.0/5 (92 download)

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Book Synopsis Weak Scale Supersymmetry by : Howard Baer

Download or read book Weak Scale Supersymmetry written by Howard Baer and published by Cambridge University Press. This book was released on 2023-01-31 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: This OA text develops the basic concepts of supersymmetry for experimental and phenomenological particle physicists and graduate students.

Search for the Higgs Boson Decaying to Four Leptons in the ATLAS Detector at LHC and Studies of Muon Isolation and Energy Loss

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Publisher :
ISBN 13 :
Total Pages : 206 pages
Book Rating : 4.:/5 (758 download)

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Book Synopsis Search for the Higgs Boson Decaying to Four Leptons in the ATLAS Detector at LHC and Studies of Muon Isolation and Energy Loss by : Bruno Lenzi

Download or read book Search for the Higgs Boson Decaying to Four Leptons in the ATLAS Detector at LHC and Studies of Muon Isolation and Energy Loss written by Bruno Lenzi and published by . This book was released on 2010 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: The central subject of this thesis is the evaluation of the discovery potential of the Higgs boson through its decay into four leptons (electrons and muons) in the ATLAS experiment installed at the Large Hadron Collider (LHC). The LHC was designed to accelerate proton beams at a center of mass energy of 14~TeV and started its physics program with 7~TeV collisions in the beginning of 2010. An inclusive analysis involving all tle production modes and an exclusive one aiming at production through vector boson fusion (VBF), studied for the first time in the collaboration are presented. Both are capable of discovering the Higgs boson after a few years of LHC operation, with integrated luminosities of 30~fb[dollar]^{-1}[dollar]. The first one covers most part of a Higgs mass window from 130 to 500~GeV. The second one concentrates on masses around 180~GeV and above, exploiting ftle presence of high energy jets with large separations in pseudo-rapidity to increase the signal over background ratio. An important part of the document is devoted to the reconstruction of muon isolation and energy loss in the ATLAS calorimeters. A software package that optimized the way of treating the energy deposits was developed and tested on simulated data and cosmic-ray events, leading ta improvements in the muon momentum resolution and the distinction between muons from heavy quark and vector boson decays. As a consequence of the last result one of the dominant backgrounds to the [dollar]H \to 4\mu[dollar] channel, [dollar]Z\bbar[dollar], is expected to be reduced by almost a factor of two.

A Search for Massive Resonances in Final States with Boosted Top-antitop Pairs Decaying Into a Lepton and Jets with the ATLAS Detector at the Large Hadron Collider

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Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (16 download)

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Book Synopsis A Search for Massive Resonances in Final States with Boosted Top-antitop Pairs Decaying Into a Lepton and Jets with the ATLAS Detector at the Large Hadron Collider by : Janna Katharina Behr

Download or read book A Search for Massive Resonances in Final States with Boosted Top-antitop Pairs Decaying Into a Lepton and Jets with the ATLAS Detector at the Large Hadron Collider written by Janna Katharina Behr and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

The Large Hadron Collider

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Publisher : Springer
ISBN 13 : 3319150014
Total Pages : 554 pages
Book Rating : 4.3/5 (191 download)

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Book Synopsis The Large Hadron Collider by : Thomas Schörner-Sadenius

Download or read book The Large Hadron Collider written by Thomas Schörner-Sadenius and published by Springer. This book was released on 2015-05-15 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive volume summarizes and structures the multitude of results obtained at the LHC in its first running period and draws the grand picture of today’s physics at a hadron collider. Topics covered are Standard Model measurements, Higgs and top-quark physics, flavour physics, heavy-ion physics, and searches for supersymmetry and other extensions of the Standard Model. Emphasis is placed on overview and presentation of the lessons learned. Chapters on detectors and the LHC machine and a thorough outlook into the future complement the book. The individual chapters are written by teams of expert authors working at the forefront of LHC research.

A Search for Exotic Higgs Decays

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Publisher : Springer Nature
ISBN 13 : 3031304667
Total Pages : 201 pages
Book Rating : 4.0/5 (313 download)

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Book Synopsis A Search for Exotic Higgs Decays by : Jackson Burzynski

Download or read book A Search for Exotic Higgs Decays written by Jackson Burzynski and published by Springer Nature. This book was released on 2023-05-23 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: The absence of new physics at the TeV scale observed thus far at the Large Hadron Collider (LHC) motivates an increasing focus on searches for weakly-coupled new particles and exotic signatures. In particular, particles with macroscopic mean proper lifetimes, known as long-lived particles (LLPs), are of significant interest due to their ability to elude the majority of searches which rely on the assumption that Beyond Standard Model particles decay close to the primary interaction point. Many models which aim to solve various issues with the Standard Model (SM) introduce new particles with lifetimes that are either unconstrained, or even shown to prefer the macroscopic regime. These theories often point to the Higgs boson as a possible portal to new physics, with exotic Higgs decays being the primary phenomenological consequence and means of discovery. It is well motivated both from theory and experimental constraints to consider the scenario in which the particles produced in these exotic decays have macroscopic proper lifetimes and give rise to unique detector signatures. This work describes a search for exotic decays of the Higgs boson to two long-lived, neutral, spin-0 particles which subsequently decay to pairs of b quarks, giving the striking signature of displaced hadronic jets in the ATLAS inner detector. Several other ATLAS searches have probed this decay topology previously, excluding branching ratios of the Higgs boson to LLPs of more than 10% for proper lifetimes greater than 100mm. These searches relied on dedicated triggers designed to select events with LLPs decaying in the ATLAS calorimeter or muon spectrometer. The lack of an equivalent trigger for LLP decays in the ATLAS inner detector has been a limiting factor in probing LLP lifetimes less than 100mm. To circumvent the difficulty of triggering on LLP decays, the search presented in this thesis exploits the ZH associated production mode, relying on leptonic trigger signatures to select interesting events. This is the first search for Higgs boson decays into LLPs to exploit this analysis methodology and additionally makes use of several novel methods for both background rejection and background estimation. No excess over Standard Model predictions is observed, and upper limits are set on the branching ratio of the Higgs boson to LLPs . Depending on the mass of the LLP, branching ratios greater than 10% are excluded for lifetimes as small as 4mm and as large as 100mm, probing an important gap in the ATLAS exotic Higgs decay programme. In comparison to the previous searches for Higgs decays to LLPs, these are among the most stringent limits placed on this scenario, and for LLPs with masses below 40 GeV these results represent the strongest existing constraints on the branching ratio of the Higgs boson to LLPs in this lifetime regime.