Search For The Standard Model Higgs Boson Decaying Into B Overline B Produced In Association With Top Quarks Decaying Hadronically In Pp Collisions At Sqrt S
DOWNLOAD
Download Search For The Standard Model Higgs Boson Decaying Into B Overline B Produced In Association With Top Quarks Decaying Hadronically In Pp Collisions At Sqrt S PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Search For The Standard Model Higgs Boson Decaying Into B Overline B Produced In Association With Top Quarks Decaying Hadronically In Pp Collisions At Sqrt S book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Search For The Standard Model Higgs Boson Decaying Into B Overline B Produced In Association With Top Quarks Decaying Hadronically In Pp Collisions At Sqrt S
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2016
Search For The Standard Model Higgs Boson Decaying Into B Overline B Produced In Association With Top Quarks Decaying Hadronically In Pp Collisions At Sqrt S written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
In this paper, a search for Higgs boson production in association with a pair of top quarks ($ t\overline{t} $H) is performed, where the Higgs boson decays to $ b\overline{b} $ , and both top quarks decay hadronically. The data used correspond to an integrated luminosity of 20.3 fb -1 of pp collisions at √s = 8 TeV collected with the ATLAS detector at the Large Hadron Collider. The search selects events with at least six energetic jets and uses a boosted decision tree algorithm to discriminate between signal and Standard Model background. The dominant multijet background is estimated using a dedicated data-driven technique. For a Higgs boson mass of 125 GeV, an upper limit of 6.4 (5.4) times the Standard Model cross section is observed (expected) at 95% confidence level. The best-fit value for the signal strength is [mu] = 1.6 ± 2.6 times the Standard Model expectation for mH = 125 GeV. Combining all $ t\overline{t}$H searches carried out by ATLAS at √s = 8 and 7 TeV, an observed (expected) upper limit of 3.1 (1.4) times the Standard Model expectation is obtained at 95% confidence level, with a signal strength [mu] = 1.7 ± 0.8.
Measurement Of Higgs Boson Decay Into B Quarks In Associated Production With A Top Quark Pair In Pp Collisions At Square Root S
DOWNLOAD
Author : [Study Group] ATLAS Collaboration CERN
language : en
Publisher:
Release Date : 2022
Measurement Of Higgs Boson Decay Into B Quarks In Associated Production With A Top Quark Pair In Pp Collisions At Square Root S written by [Study Group] ATLAS Collaboration CERN and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2022 with categories.
Abstract: The associated production of a Higgs boson and a top-quark pair is measured in events characterised by the presence of one or two electrons or muons. The Higgs boson decay into a b-quark pair is used. The analysed data, corresponding to an integrated luminosity of 139 fb−1, were collected in proton-proton collisions at the Large Hadron Collider between 2015 and 2018 at a centre-of-mass energy of s√ = 13 TeV. The measured signal strength, defined as the ratio of the measured signal yield to that predicted by the Standard Model, is 0.35+0.36−0.34. This result is compatible with the Standard Model prediction and corresponds to an observed (expected) significance of 1.0 (2.7) standard deviations. The signal strength is also measured differentially in bins of the Higgs boson transverse momentum in the simplified template cross-section framework, including a bin for specially selected boosted Higgs bosons with transverse momentum above 300 GeV
Search For The Standard Model Higgs Boson Produced In Association With Top Quarks And Decaying Into A B B Pair In P P Collisions At S
DOWNLOAD
Author : Felix Bührer
language : en
Publisher:
Release Date : 2018
Search For The Standard Model Higgs Boson Produced In Association With Top Quarks And Decaying Into A B B Pair In P P Collisions At S written by Felix Bührer and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018 with categories.
Measurement Of The Associated Production Of A Higgs Boson Decaying Into B Quarks With A Vector Boson At High Transverse Momentum In Pp Collisions At Square Root S
DOWNLOAD
Author : ATLAS Collaboration CERN
language : en
Publisher:
Release Date : 2021
Measurement Of The Associated Production Of A Higgs Boson Decaying Into B Quarks With A Vector Boson At High Transverse Momentum In Pp Collisions At Square Root S written by ATLAS Collaboration CERN and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021 with categories.
Abstract: The associated production of a Higgs boson with a W or Z boson decaying into leptons and where the Higgs boson decays to a pair is measured in the high vector-boson transverse momentum regime, above 250 GeV, with the ATLAS detector. The analysed data, corresponding to an integrated luminosity of , were collected in proton-proton collisions at the Large Hadron Collider between 2015 and 2018 at a centre-of-mass energy of . The measured signal strength, defined as the ratio of the measured signal yield to that predicted by the Standard Model, is corresponding to an observed (expected) significance of 2.1 (2.7) standard deviations. Cross-sections of associated production of a Higgs boson decaying into b quark pairs with a W or Z gauge boson, decaying into leptons, are measured in two exclusive vector boson transverse momentum regions, 250-400 GeV and above 400 GeV, and interpreted as constraints on anomalous couplings in the framework of a Standard Model effective field theory
Search For Charged Higgs Bosons Produced In Association With A Top Quark And Decaying Via H U2192 Using Pp Collision Data Recorded At
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2016
Search For Charged Higgs Bosons Produced In Association With A Top Quark And Decaying Via H U2192 Using Pp Collision Data Recorded At written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
In this paper, charged Higgs bosons produced in association with a single top quark and decaying via H±→?? are searched for with the ATLAS experiment at the LHC, using proton–proton collision data at √s=13 TeV corresponding to an integrated luminosity of 3.2 fb-1. The final state is characterised by the presence of a hadronic ? decay and missing transverse momentum, as well as a hadronically decaying top quark, resulting in the absence of high-transverse-momentum electrons and muons. The data are found to be consistent with the expected background from Standard Model processes. A statistical analysis leads to 95% confidence-level upper limits on the production cross section times branching fraction, ?(pp→[b]tH±)×BR(H±→??) , between 1.9 pb and 15 fb, for charged Higgs boson masses ranging from 200 to 2000 GeV. Finally, the exclusion limits for this search surpass those obtained with the proton–proton collision data recorded at √s=8 TeV.
Search For A Standard Model Higgs Boson Produced In Association With A Top Quark Pair And Decaying To Bottom Quarks Using A Matrix Element Method
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2015
Search For A Standard Model Higgs Boson Produced In Association With A Top Quark Pair And Decaying To Bottom Quarks Using A Matrix Element Method written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
Combined Results Of Searches For The Standard Model Higgs Boson In Pp Collisions At Sqrt S
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2012
Combined Results Of Searches For The Standard Model Higgs Boson In Pp Collisions At Sqrt S written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012 with categories.
Combined results are reported from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s)=7 TeV in five Higgs boson decay modes: gamma pair, b-quark pair, tau lepton pair, W pair, and Z pair. The explored Higgs boson mass range is 110-600 GeV. The analysed data correspond to an integrated luminosity of 4.6-4.8 inverse femtobarns. The expected excluded mass range in the absence of the standard model Higgs boson is 118-543 GeV at 95% CL. The observed results exclude the standard model Higgs boson in the mass range 127-600 GeV at 95% CL, and in the mass range 129-525 GeV at 99% CL. An excess of events above the expected standard model background is observed at the low end of the explored mass range making the observed limits weaker than expected in the absence of a signal. The largest excess, with a local significance of 3.1 sigma, is observed for a Higgs boson mass hypothesis of 124 GeV. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-600 (110-145) GeV is estimated to be 1.5 sigma (2.1 sigma). More data are required to ascertain the origin of this excess.
A Search For The Standard Model Higgs Boson In The Process Zh Rightarrow Ell Ell B Bar B In 4 1 Unit Fb 1 Of Cdf Ii Data
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2010
A Search For The Standard Model Higgs Boson In The Process Zh Rightarrow Ell Ell B Bar B In 4 1 Unit Fb 1 Of Cdf Ii Data written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with categories.
The standard model of particle physics provides a detailed description of a universe in which all matter is composed of a small number of fundamental particles, which interact through the exchange of force - carrying gauge bosons (the photon, W{sup ±}, Z and gluons). The organization of the matter and energy in this universe is determined by the effects of three forces; the strong, weak, and electromagnetic. The weak and electromagnetic forces are the low energy manifestations of a single electro-weak force, while the strong force binds quarks into protons and neutrons. The standard model does not include gravity, as the effect of this force on fundamental particles is negligible. Four decades of experimental tests, spanning energies from a few electron-volts (eV) up to nearly two TeV, confirm that the universe described by the standard model is a reasonable approximation of our world. For example, experiments have confirmed the existence of the top quark, the W{sup ±} and the Z bosons, as predicted by the standard model. The latest experimental averages for the masses of the top quark, W{sup ±} and Z are respectively 173.1 ± 0.6(stat.) {+-} 1.1(syst.), 80.399 {+-} 0.023 and 91.1876 {+-} 0.0021 GeV/c2. The SM is a gauge field theory of zero mass particles. However, the SM is able to accommodate particles with non-zero mass through the introduction of a theoretical Higgs field which permeates all of space. Fermions gain mass through interactions with this field, while the longitudinal components of the massive W{sup {+-}} and Z are the physical manifestations of the field itself. Introduction of the Higgs field, directly leads to the predicted existence of an additional particle, the Higgs boson. The Higgs boson is the only particle of the standard model that has not been observed, and is the only unconfirmed prediction of the theory. The standard model describes the properties of the Higgs boson in terms of its mass, which is a free parameter in the theory. Experimental evidence suggests that the Higgs mass has a value between 114.4 and 186 GeV/c2. Particles with a mass in this range can be produced in collisions of less massive particles accelerated to near the speed of light. Currently, one of only a few machines capable of achieving collision energies large enough to potentially produce a standard model Higgs boson is the Tevatron proton-antiproton collider located at Fermi National Accelerator Laboratory in Batavia, Illinois. This dissertation describes the effort to observe the standard model Higgs in Tevatron collisions recorded by the Collider Detector at Fermilab (CDF) II experiment in the ZH --> ll−b{bar b} production and decay channel. In this process, the Higgs is produced along with a Z boson which decays to a pair of electrons or muons (Z --> ll−), while the Higgs decays to a bottom anti-bottom quark pair (H --> b{bar b}). A brief overview of the standard model and Higgs theory is presented in Chapter 2. Chapter 3 explores previous searches for the standard model Higgs at the Tevatron and elsewhere. The search presented in this dissertation expands upon the techniques and methods developed in previous searches. The fourth chapter contains a description of the Tevatron collider and the CDF II detector. The scope of the discussion in Chapter 4 is limited to the experimental components relevant to the current ZH --> l+l−b{bar b} search. Chapter 5 presents the details of object reconstruction; the methods used to convert detector signals into potential electrons, muons or quarks. Chapter six describes the data sample studied for the presence of a ZH --> l+l−b{bar b} signal and details the techniques used to model the data. The model accounts for both signal and non-signal processes (backgrounds) which are expected to contribute to the observed event sample. Chapters 7 and 8 summarize the event selection applied to isolate ZH --> l+l−b{bar b} candidate events from the data sample, and the advanced techniques employed to maximize the separation of the signal from background processes. Chapters 9 and 10 present the systematic uncertainties affecting our modeling of the data sample and the results of the search. Chapter 11 presents a discussion of ZH --> l+l−b{bar b} in the context of the overall Tevatron efforts to observe a standard model Higgs signal.
A Search For The Standard Model Higgs Boson In The Process Zh U2192 L L B Bar B In 4 1 Fb 1 Of Cdf Ii Data
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2010
A Search For The Standard Model Higgs Boson In The Process Zh U2192 L L B Bar B In 4 1 Fb 1 Of Cdf Ii Data written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with categories.
The standard model of particle physics provides a detailed description of a universe in which all matter is composed of a small number of fundamental particles, which interact through the exchange of force - carrying gauge bosons (the photon, W ±, Z and gluons). The organization of the matter and energy in this universe is determined by the effects of three forces; the strong, weak, and electromagnetic. The weak and electromagnetic forces are the low energy manifestations of a single electro-weak force, while the strong force binds quarks into protons and neutrons. The standard model does not include gravity, as the effect of this force on fundamental particles is negligible. Four decades of experimental tests, spanning energies from a few electron-volts (eV) up to nearly two TeV, confirm that the universe described by the standard model is a reasonable approximation of our world. For example, experiments have confirmed the existence of the top quark, the W± and the Z bosons, as predicted by the standard model. The latest experimental averages for the masses of the top quark, W± and Z are respectively 173.1 ± 0.6(stat.) ± 1.1(syst.), 80.399 ± 0.023 and 91.1876 ± 0.0021 GeV/c2. The SM is a gauge field theory of zero mass particles. However, the SM is able to accommodate particles with non-zero mass through the introduction of a theoretical Higgs field which permeates all of space. Fermions gain mass through interactions with this field, while the longitudinal components of the massive W± and Z are the physical manifestations of the field itself. Introduction of the Higgs field, directly leads to the predicted existence of an additional particle, the Higgs boson. The Higgs boson is the only particle of the standard model that has not been observed, and is the only unconfirmed prediction of the theory. The standard model describes the properties of the Higgs boson in terms of its mass, which is a free parameter in the theory. Experimental evidence suggests that the Higgs mass has a value between 114.4 and 186 GeV/c2. Particles with a mass in this range can be produced in collisions of less massive particles accelerated to near the speed of light. Currently, one of only a few machines capable of achieving collision energies large enough to potentially produce a standard model Higgs boson is the Tevatron proton-antiproton collider located at Fermi National Accelerator Laboratory in Batavia, Illinois. This dissertation describes the effort to observe the standard model Higgs in Tevatron collisions recorded by the Collider Detector at Fermilab (CDF) II experiment in the ZH →l+l-b$ar{b}$ production and decay channel. In this process, the Higgs is produced along with a Z boson which decays to a pair of electrons or muons (Z →l+l-), while the Higgs decays to a bottom anti-bottom quark pair (H → b$ar{b}$). A brief overview of the standard model and Higgs theory is presented in Chapter 2. Chapter 3 explores previous searches for the standard model Higgs at the Tevatron and elsewhere. The search presented in this dissertation expands upon the techniques and methods developed in previous searches. The fourth chapter contains a description of the Tevatron collider and the CDF II detector. The scope of the discussion in Chapter 4 is limited to the experimental components relevant to the current ZH →l+l-b$ar{b}$ search. Chapter 5 presents the details of object reconstruction; the methods used to convert detector signals into potential electrons, muons or quarks. Chapter six describes the data sample studied for the presence of a ZH →l+l-b$ar{b}$ signal and details the techniques used to model the data. The model accounts for both signal and non-signal processes (backgrounds) which are expected to contribute to the observed event sample. Chapters 7 and 8 summarize the event selectio...
A Search For Charged Higgs Boson Decays Of The Top Quark Using Hadronic Decays Of The Tau Lepton In Proton Antiproton Collisions At Square Root S
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2000
A Search For Charged Higgs Boson Decays Of The Top Quark Using Hadronic Decays Of The Tau Lepton In Proton Antiproton Collisions At Square Root S written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2000 with categories.
The Standard Model predicts the existence of one neutral scalar Higgs boson, which is a remnant of the mechanism that breaks the SU(2)[sub L]xU(1)[sub Y] electroweak symmetry and generates masses for the heavy vector bosons and fermions. Many extensions to the Standard Model predict two or more Higgs doublets, resulting in a larger spectrum of Higgs bosons including a charged Higgs boson (H[sup [+-]]). For a light charged Higgs boson mass, the top decay into a charged Higgs boson and bottom quark might occur. This thesis presents results of a direct search for this top quark decay mode via the charged Higgs decay to a tau lepton and tau-neutrino, using the hadronic decays of the tau leptons. The search data consist of 100 pb[sup -1] of Run 1 data collected between 1992-1995 at the CDF detector, from p[anti p] collisions at a center-of-mass energy of 1.8 TeV produced at Fermilab's Tevatron accelerator. A total of seven events are observed in two search channels with an expected background contribution of 7.4[+-]2.0 events coming from fake taus (5.4[+-]1.5), heavy vector boson decays with jets (1.9[+-]1.3) and dibosons(0.08[+-]0.06). Lacking evidence for a signal, we set limits on charged Higgs production at the 95% confidence level in the charged Higgs mass plane versus tan[beta](a parameter of the theory) for a top quark mass of 175 GeV/c[sup 2] and for top production cross sections ([sigma][sub t[anti t]]) of 5.0 and 7.5 pb, assuming the Type-II Two-Higgs-Doublet-Model. For large tan[beta], this analysis excludes a charged Higgs boson of mass below 147(158)GeV/c[sup 2] for [sigma][sub t[anti t]]=5.0(7.5)pb. Using the Standard Model measured top quark cross section from CDF, this limit increases to 168 GeV/c[sup 2] and we also exclude a branching fraction of top decays via this charged Higgs mode of greater than 43% for charged Higgs masses below 168 GeV/c[sup 2].