Search for the Standard Model Higgs Boson in the H to Tau+ Tau- Decay Mode in Sqrt(s) PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Search for the Standard Model Higgs Boson in the H to Tau+ Tau- Decay Mode in Sqrt(s) PDF full book. Access full book title Search for the Standard Model Higgs Boson in the H to Tau+ Tau- Decay Mode in Sqrt(s) by . Download full books in PDF and EPUB format.
Author: Publisher: ISBN: Category : Languages : en Pages : 30
Book Description
A search for the neutral Higgs bosons predicted by the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is performed on data from proton-proton collisions at a centre-of-mass energy of 8TeV collected with the ATLAS detector at the Large Hadron Collider. The samples used for this search were collected in 2012 and correspond to integrated luminosities in the range 19.5-20.3 fb-1. The MSSM Higgs bosons are searched for in the [tau] [tau] final state. No significant excess over the expected background is observed, and exclusion limits are derived for the production cross section times branching fraction of a scalar particle as a function of its mass. The results are also interpreted in the MSSM parameter space for various benchmark scenarios.
Author: Publisher: ISBN: Category : Languages : en Pages : 30
Book Description
A search for the neutral Higgs bosons predicted by the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is performed on data from proton-proton collisions at a centre-of-mass energy of 8TeV collected with the ATLAS detector at the Large Hadron Collider. The samples used for this search were collected in 2012 and correspond to integrated luminosities in the range 19.5-20.3 fb-1. The MSSM Higgs bosons are searched for in the [tau] [tau] final state. No significant excess over the expected background is observed, and exclusion limits are derived for the production cross section times branching fraction of a scalar particle as a function of its mass. The results are also interpreted in the MSSM parameter space for various benchmark scenarios.
Author: Alexander I Studenikin Publisher: World Scientific ISBN: 9814436844 Category : Science Languages : en Pages : 481
Book Description
This volume is devoted to a wide variety of investigations, both in theory and experiment, of particle physics such as electroweak theory, fundamental symmetries, tests of the Standard Model and beyond, neutrino and astroparticle physics, heavy quark physics, non-perturbative QCD, quantum gravity effects, and present and future accelerator physics.
Author: Moskovskiĭ gosudarstvennyĭ universitet im. M.V. Lomonosova Publisher: World Scientific ISBN: 9814436828 Category : Science Languages : en Pages : 481
Book Description
This volume is devoted to a wide variety of investigations, both in theory and experiment, of particle physics such as electroweak theory, fundamental symmetries, tests of the Standard Model and beyond, neutrino and astroparticle physics, heavy quark physics, non-perturbative QCD, quantum gravity effects, and present and future accelerator physics.
Author: Publisher: ISBN: Category : Languages : en Pages : 196
Book Description
The question of the nature and principles of the universe and our place in it is the driving force of science since Mesopotamian astronomers glanced for the first time at the starry sky and Greek atomism has been formulated. During the last hundred years modern science was able to extend its knowledge tremendously, answering many questions, opening entirely new fields but as well raising many new questions. Particularly Astronomy, Astroparticle Physics and Particle Physics lead the race to answer these fundamental and ancient questions experimentally. Today it is known that matter consists of fermions, the quarks and leptons. Four fundamental forces are acting between these particles, the electromagnetic, the strong, the weak and the gravitational force. These forces are mediated by particles called bosons. Our confirmed knowledge of particle physics is based on these particles and the theory describing their dynamics, the Standard Model of Particles. Many experimental measurements show an excellent agreement between observation and theory but the origin of the particle masses and therefore the electroweak symmetry breaking remains unexplained. The mechanism proposed to solve this issue involves the introduction of a complex doublet of scalar fields which generates the masses of elementary particles via their mutual interactions. This Higgs mechanism also gives rise to a single neutral scalar boson with an unpredicted mass, the Higgs boson. During the last twenty years several experiments have searched for the Higgs boson but so far it escaped direct observation. Nevertheless these studies allow to further constrain its mass range. The last experimental limits on the Higgs mass have been set in 2001 at the LEP collider, an electron positron machine close to Geneva, Switzerland. The lower limit set on the Higgs boson mass is m{sub H}> 114.4 GeV/c2 and remained for many years the last experimental constraint on the Standard Model Higgs Boson due to the shutdown of the LEP collider and the experimental challenges at hadron machines as the Tevatron. This thesis was performed using data from the D0 detector located at the Fermi National Accelerator Laboratory in Batavia, IL. Final states containing two electrons or a muon and a tau in combination with missing transverse energy were studied to search for the Standard Model Higgs boson, utilizing up to 4.2 fb−1 of integrated luminosity. In 2008 the CDF and D0 experiments in a combined effort were able to reach for the first time at a hadron collider the sensitivity to further constrain the possible Standard Model Higgs boson mass range. The research conducted for this thesis played a pivotal role in this effort. Improved methods for lepton identification, background separation, assessment of systematic uncertainties and new decay channels have been studied, developed and utilized. Along with similar efforts at the CDF experiment these improvements led finally the important result of excluding the presence of a Standard Model Higgs boson in a mass range of m{sub H} = 160-170 GeV/c2 at 95% Confidence Level. Many of the challenges and methods found in the present analysis will probably in a similar way be ingredients of a Higgs boson evidence or discovery in the near future, either at the Tevatron or more likely at the soon starting Large Hadron Collider (LHC). Continuing to pursue the Higgs boson we are looking forward to many exciting results at the Tevatron and soon at the LHC. In Chapter 2 an introduction to the Standard Model of particle physics and the Higgs mechanism is given, followed by a brief outline of existing theoretical and experimental constraints on the Higgs boson mass before summarizing the Higgs boson production modes. Chapter 3 gives an overview of the experimental setup. This is followed by a description of the reconstruction of the objects produced in proton-antiproton collisions in Chapter 4 and the necessary calorimeter calibrations in Chapter 5. Chapter 6 follows with an explanation of the phenomenology of the proton-antiproton collisions and the data samples used. In Chapter 7 the search for the Standard Model Higgs boson using a di-electron final state is discussed, followed by the analysis of the final states using muons and hadronic decaying taus in Chapter 8. Finally a short outlook for the prospects of Higgs boson searches is given in Chapter 9.
Author: Publisher: ISBN: Category : Languages : en Pages : 238
Book Description
This thesis describes the search for the Standard Model Higgs boson decaying to tau lepton pairs, in the Tevatron proton-antiproton collisions at a center of mass energy $\sqrt{s}$ = 1.96 TeV. The search is based on approximately 2.3 fb$^{-1}$ of CDF Run II data and is performed by considering the following signal processes: WH($\rightarrow\tau\tau$), ZH($\rightarrow\tau\tau$), qHq'$\rightarrow$q$\tau\tau$q' and gg$\rightarrow$H$\rightarrow\tau\tau$. Events are selected by requiring an hadronic tau and one isolated electron or muon, coming from the leptonic decay of one of the two taus. In addition, at least one calorimeter jet must be present in the final state. We expect 921.8$\pm$48.9 background events in the 1 jet channel and 159.4$\pm$11.6 in the $\ge$ 2 jets channel, while in data we observe 965 and 166 events, respectively. In order to improve the search sensitivity we employ a multivariate technique, based on a set of Boosted Decision Trees trained to get the best sep aration between signal and the dominant sources of background. We observe no evidence for a Higgs boson signal and therefore we set a 95\% confidence level (C.L.) upper limit on the cross section relative to the SM predictions ($\sigma/\sigma_{\mathrm{SM}}$). Results are presented for the Higgs boson mass varying from M$_\mathrm{H}$ = 100 GeV/$c^2$ to M$_\mathrm{H}$ = 150 GeV/$c^2$. For the mass hypothesis of 120 GeV/c$^2$ the observed limit is 27.2, while the corresponding expected value is 23.4$^{+9.8}_{-6.4}$.
Author: Ian James Howley Publisher: ISBN: Category : Higgs bosons Languages : en Pages :
Book Description
Presented in this dissertation is a search for the standard model (SM) Higgs boson using the D[zero] detector at Fermilab in Batavia, IL. The SM is a fantastically accurate theory describing the fundamental interactions and particles of the Universe. The only undiscovered particle in the SM is the Higgs boson, which is hypothesized to be responsible for electroweak symmetry breaking and giving mass to all other particles. Considered in this search is the process H + X -> e[tau]hjj, where e is an electron, [tau]h is the hadronic decay of a [tau], and j is a jet, using p[p-bar] collisions at center of mass energy s−1 = 1.96 TeV. This search includes three production modes: associated production, gluon fusion and vector boson fusion. It also utilizes two decay channels: H -> [tau][tau] and H -> WW. A new technique, dubbed the Global Boosted Decision Tree, is introduced which offers a means of providing continuity to a multivariate search as a function of a particular parameter, in this case, the mass of the Higgs boson. The observed (expected) limit on the ratio of cross section times branching fraction to the SM at 95% confidence level is 14.6 (16.0) at mH = 125 GeV. This result is combined with the related channel H + X -> [mu][tau]hjj and produced an observed (expected) limit of 9.0 (11.3) at mH = 125 GeV.
Author: Matthew Hans Chan Publisher: ISBN: Category : Languages : en Pages : 204
Book Description
A search for the Standard Model Higgs boson in the H --> rr channel is presented. The search is performed on proton collision data collected by the Compact Muon Solenoid at the Large Hadron Collider. The data corresponds to 4.9 fb-1 of proton collisions at [square root of]s = 7 TeV and 19.5 fb-1 at [square root of]s = 8 TeV. The search is based on di-tau events in which one tau decays into an electron or muon, and the other tau decays into hadrons. The search focuses on Higgs masses between 110 GeV and 145 GeV. The analysis reveals no statistically significant excess in the data over the Standard Model backgrounds. Upper limits on the Higgs production cross section at the 95% confidence level are established. The observed limit is statistically consistent with the expected limit in the background-only hypothesis but does not exclude any Higgs mass.
Author: Andrey Elagin Publisher: ISBN: Category : Languages : en Pages :
Book Description
A search for the Higgs boson decaying to tau tau using 7.8 fb^-1 of pp collisions at 1.96 TeV collected with CDF II detector is presented. The search is sensitive to four production mechanisms of the Higgs boson: ggH, WH, ZH and VBF. Modes where one tau decay leptonically, and another decay, hadronically, are considered. Two novel techniques are developed and used in the search. A Probabilistic Particle Flow Algorithm is used for energy measurements of the hadronic tau candidates. The signal is discriminated from backgrounds by the Missing Mass Calculator, which allows for full invariant mass reconstruction of tau tau pair. The data are found to be consistent with the background only hypothesis. Therefore a 95% confidence level upper limit on the Standard Model Higgs boson cross section was set. At M_H=120 GeV/c^2 observed limit is 14.9 x sigma_SM x Br(H -> tau tau).
Author: Publisher: ISBN: Category : Languages : en Pages : 245
Book Description
We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with zero, one, or two or more jets using data corresponding to an integrated luminosity of up to 7.3 fb−1 collected with the D0 detector at the Fermilab Tevatron collider. The analysis is sensitive to Higgs boson production via gluon gluon fusion, associated vector boson production, and vector boson fusion, and to Higgs boson decays to tau lepton pairs or W boson pairs. Observed (expected) limits are set on the ratio of 95% C.L. upper limits on the cross section times branching ratio, relative to those predicted by the Standard Model, of 14 (22) at a Higgs boson mass of 115 GeV and 7.7 (6.8) at 165 GeV.
Author: 
Author: 
Author: Alexander I Studenikin
Author: Moskovskiĭ gosudarstvennyĭ universitet im. M.V. Lomonosova![Search for the Standard Model Higgs Boson in the Decay Mode H-] WW-] Lnulnu PDF](https://books.google.com/books/content/images/frontcover/3xPsnQAACAAJ?fife=w80-h100)
Author: 
Author: ![Search for the Standard Model Higgs Boson in E[tau] Final States PDF](https://books.google.com/books/content/images/frontcover/lTtAngEACAAJ?fife=w80-h100)
Author: Ian James Howley
Author: Matthew Hans Chan
Author: Andrey Elagin
Author: ![Search for the Standard Model Higgs Boson in the Decay Mode H → W+ W- → L+νl-ν [l+ Nu L- Nu] at the DØ Experiment PDF](https://books.google.com/books/content/images/frontcover/eU_NzQEACAAJ?fife=w80-h100)
Author: Björn Penning