Download or read book Higgs Effects in the Polarization of Top Quarks written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Top quarks produced in high-energy collisions should exhibit a parity-conserving spin polarization normal to the production plane which can be measured by the asymmetry in their leptonic decays. A portion of this effect, which can be calculated in perturbation theory, is attributable to the quark's QCD interactions. In addition, there is a component of the polarization due to the Yukawa coupling (g[sub Y] [congruent] m[sub T]/(250 GeV)) of the top quark with the Higgs sector. We can demonstrate the interplay of QCD and Yukawa forces in the polarization for e[sup +]e[sup [minus]] [yields] 4 T[bar T]. Assuming M[sub H]> 2M[sub T] and that the Higgs particle is not discovered before the top quark, measurement of top quark polarization in e[sup +]e[sup [minus]] or hadron-hadron collisions can be used to specify an approximate mass for the Higgs and guide direct searches.

Download or read book Impact of Tau Polarization on the Study of the MSSM Charged Higgs Bosons in Top Quark Decays at the ILC written by C. E. M. Wagner and published by . This book was released on 2005 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The process of top quark pair production at the ILC with subsequent decays of one of the top quarks to a charged Higgs boson and b-quark is considered. The charged Higgs decays to tau leptons whose polarization is the opposite to those coming from W bosons. This difference is reflected in the energy distributions of the tau decay products in the top quark rest frame, which can be reconstructed at the ILC using the recoil mass technique. We present an analysis including spin correlations, backgrounds, ISR/FSR and beamstrahlung, and show that a fit of the shape of the pion energy spectrum yields the charged Higgs boson mass with an accuracy of about 1 GeV.

Download or read book Perspectives On Higgs Physics written by Gordon Kane and published by World Scientific. This book was released on 1993-01-08 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: The masses of fermions and gauge bosons enter the Standard Model through the Higgs mechanism, which is satisfactory technically but is not understood physically. We do not know what nature really does to give mass to particles, nor what experimental clues will lead us to nature's solution. Understanding Higgs physics is necessary in order to complete the Standard Model, and to learn how to extend it and improve its foundations.This book is a collection of current work and thinking about these questions by active workers. It speculates about what form the answers will take, as well as updates and extends previous books and reviews. Some chapters emphasize theoretical questions, some focus on connections with other areas of physics, and some discuss how we can get the data to uncover nature's solution.

Download or read book Two loop Virtual Top quark Effect on Higgs Boson Decay to Bottom Quarks written by Mathias Butenschön and published by . This book was released on 2006 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Higgs Boson Produced With Top Quarks in Fully Hadronic Signatures written by Daniel Salerno and published by Springer Nature. This book was released on 2019-10-25 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented in this PhD dissertation is the first search at CMS for Higgs bosons produced in association with top quarks (ttH) in a final state consisting of only jets. The results presented in this book uncover a new class of ttH events that will help us elucidate our understanding of the Yukawa sector interactions between the Higgs boson and the top quark. Despite this being the most common decay signature for ttH, a large contamination of SM backgrounds makes it the most challenging for extracting a signal from data. The PhD thesis presents many sophisticated tools and techniques that were developed in order to overcome these challenges. These tools pave the way for future analyses to investigate other standard model and beyond-standard model physics.

Download or read book Renormalization Group Analysis of Charged Higgs Effects in epsilon epsilon for a Heavy Top Quark written by Gerhard Buchalla and published by . This book was released on 1990 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polarization in Heavy Quark Decays written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis I concentrate on the angular correlations in top quark decays and their next--to--leading order (NLO) QCD corrections. I also discuss the leading--order (LO) angular correlations in unpolarized and polarized hyperon decays. In the first part of the thesis I calculate the angular correlation between the top quark spin and the momentum of decay products in the rest frame decay of a polarized top quark into a charged Higgs boson and a bottom quark in Two-Higgs-Doublet-Models: $t(uparrow)rightarrow b+H^{+}$. The decay rate in this process is split into an angular independent part (unpolarized) and an angular dependent part (polar correlation). I provide closed form formulae for the ${mathcal O}(alpha_{s})$ radiative corrections to the unpolarized and the polar correlation functions for $m_{b}neq 0$ and $m_{b}=0$. The results for the unpolarized rate agree with the existing results in the literature. The results for the polarized correlations are new. I found that, for certain values of $tanbeta$, the ${mathcal O}(alpha_s)$ radiative corrections to the unpolarized, polarized rates, and the asymmetry parameter can become quite large. In the second part I concentrate on the semileptonic rest frame decay of a polarized top quark into a bottom quark and a lepton pair: $t(uparrow) to X_b + ell^+ + nu_ell$. I analyze the angular correlations between the top quark spin and the momenta of the decay products in two different helicity coordinate systems: system 1a with the $z$--axis along the charged lepton momentum, and system 3a with the $z$--axis along the neutrino momentum. The decay rate then splits into an angular independent part (unpolarized), a polar angle dependent part (polar correlation) and an azimuthal angle dependent part (azimuthal correlation). I present closed form expressions for the ${mathcal O}(alpha_{s})$ radiative corrections to the unpolarized part and the polar and azimuthal correlations in system 1a and 3a for $m_{b}neq 0$ and $m_{b}=0$. Fo.

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.

Download or read book Higgs Effects in Top Quark Pair Production written by and published by . This book was released on 2003 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Top quark production in p{bar p} and ee− collisions is enhanced by the exchange of a Higgs boson. The enhancement factors are calculated in the threshold region using the Greens function method.

Download or read book The Beauty and the Boost A Higgs Boson Tale written by Brian Moser and published by Springer Nature. This book was released on 2023-09-19 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Precision measurements of the Higgs boson’s properties are a powerful tool to look for deviations from the predictions of the Standard Model (SM) of particle physics. The 139/fb of proton-proton collision data which have been collected by the ATLAS experiment during Run 2 of the LHC, offer an opportunity to investigate rare Higgs-boson topologies, which are particularly sensitive to new physics scenarios but experimentally difficult to access. Several such measurements, which target Higgs-boson decays to heavy-flavour quarks, as well as their combinations are presented in this thesis. A novel analysis that measures Higgs-boson production in association with a heavy vector boson V (VH, with V=W,Z) at high energies is presented. Dedicated Higgs-boson reconstruction techniques are applied to reconstruct the highly Lorentz-boosted Higgs-boson decays into pairs of bottom quarks. The measurement is subsequently combined with a VH cross-section measurement at low and intermediate pT(V) to provide a differential cross-section measurement in kinematic fiducial volumes over the largest possible pT(V) range. All cross-section measurements agree with the SM predictions within relative uncertainties that range from 30% to 300%. The results are furthermore interpreted as limits on the parameters of a SM effective field theory. Finally, a combination of measurements of Higgs decays to heavy-flavour quarks is used to experimentally determine that the Higgs-boson coupling to charm quarks is weaker than to bottom quarks, as predicted by the SM. The target audience for the thesis are physicists and physics students, in particular those with a background in high energy physics.

Download or read book Finite Lifetime Effects in Top Quark Pair Production at Threshold written by Christoph Josef Reißer and published by Cuvillier Verlag. This book was released on 2008 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Next to leading QCD and Finite Lifetime Effects in E 1hn e 1hn Tt H written by Cailin Farrell and published by Cuvillier Verlag. This book was released on 2008 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Top Quark Mass Effects in Higgs and Z Boson Pair Production and Higgs Boson Decays written by David Wellmann and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Linear Collider Physics in the New Millennium written by Keisuke Fujii and published by World Scientific. This book was released on 2005 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: The high energy electron-positron linear collider is expected to provide crucial clues to many of the fundamental questions of our time: What is the nature of electroweak symmetry breaking? Does a Standard Model Higgs boson exist, or does nature take the route of supersymmetry, technicolor or extra dimensions, or none of the foregoing? This invaluable book is a collection of articles written by experts on many of the most important topics which the linear collider will focus on. It is aimed primarily at graduate students but will undoubtedly be useful also to any active researcher on the physics of the next generation linear collider.

Download or read book Top Quark Physics at Hadron Colliders written by Arnulf Quadt and published by Springer Science & Business Media. This book was released on 2007-08-16 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: This will be a required acquisition text for academic libraries. More than ten years after its discovery, still relatively little is known about the top quark, the heaviest known elementary particle. This extensive survey summarizes and reviews top-quark physics based on the precision measurements at the Fermilab Tevatron Collider, as well as examining in detail the sensitivity of these experiments to new physics. Finally, the author provides an overview of top quark physics at the Large Hadron Collider.

Download or read book Top Quark Mass Effects in Higgs Boson Pair Production Up to NNLO written by J. Hoff and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: