A Search for Lepton-Flavor-Violating Decays of the 125 GeV Higgs Boson with Hadronically Decaying Tau Leptons in the 20.3 Fb^{-1}, \sqrt{s}

A Search for Lepton-Flavor-Violating Decays of the 125 GeV Higgs Boson with Hadronically Decaying Tau Leptons in the 20.3 Fb^{-1}, \sqrt{s}
Author: Robert Najem Clarke
Publisher:
Total Pages: 232
Release: 2016
Genre:
ISBN:

This dissertation presents a search for lepton-flavor-violating (LFV) decays of the 125 GeV Higgs boson in final states of \mu\tau_{\mathrm{had}} and e\tau_{\mathrm{had}} in the full dataset collected by the ATLAS detector in 2012. The search is based on data samples of proton--proton collisions at \sqrt{s} = 8 TeV, corresponding to an integrated luminosity of 20.3 fb^{-1}. The topology of LFV events is exploited through an optimized selection of objects and events, with signal and control regions defined by event kinematics. A binned likelihood fit searching for the presence of LFV Higgs decays is performed using the reconstructed Higgs boson mass as the discriminating variable. No such decays are observed. The expected (observed) upper limits at 95% confidence on the branching ratios for the muon and electron final states are found to be Br(H \rightarrow \mu\tau) = 1.24% (1.85%) and Br(H \rightarrow e\tau) = 2.07% (1.81%).

Theory and Design of Charged Particle Beams

Theory and Design of Charged Particle Beams
Author: Martin Reiser
Publisher: John Wiley & Sons
Total Pages: 634
Release: 2008-09-26
Genre: Science
ISBN: 3527617639

Although particle accelerators are the book's main thrust, it offers a broad synoptic description of beams which applies to a wide range of other devices such as low-energy focusing and transport systems and high-power microwave sources. Develops material from first principles, basic equations and theorems in a systematic way. Assumptions and approximations are clearly indicated. Discusses underlying physics and validity of theoretical relationships, design formulas and scaling laws. Features a significant amount of recent work including image effects and the Boltzmann line charge density profiles in bunched beams.

Gauge Theory of Weak Decays

Gauge Theory of Weak Decays
Author: Andrzej J. Buras
Publisher: Cambridge University Press
Total Pages: 739
Release: 2020-07-02
Genre: Science
ISBN: 1107034035

"The ultimate question of elementary particle physics is: What is the fundamental Lagrangian of nature surrounding us? The Lagrangian of the SM is very successful in describing nature at the currently available energy range. The discovery of the Higgs boson completed the particle spectrum of the SM and it is another proof of how well the SM works. Nevertheless the SM cannot be the end of the story and it is for sure not the fundamental Lagrangian of nature. The Lagrangian of the SM looses its validity at the latest at the Planck scale where gravitational effects become noticeable.Most physicists think of the SM as an effective theory that has to be replaced by a more fundamental theory above the TeV scale. What the word effective really means will hopefully be clear at later stages of our book. For the time being we will list some problems and open questions of the SM"--

The Physics Associated with Neutrino Masses

The Physics Associated with Neutrino Masses
Author: Diego Aristizabal Sierra
Publisher: Frontiers Media SA
Total Pages: 293
Release: 2020-01-13
Genre:
ISBN: 2889633519

This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.

A Search for Lepton Flavor Violating Decays of the Higgs Boson and a Measurement of W Boson Production Using the CMS Detector at the LHC

A Search for Lepton Flavor Violating Decays of the Higgs Boson and a Measurement of W Boson Production Using the CMS Detector at the LHC
Author: Aaron Goodman Levine
Publisher:
Total Pages: 0
Release: 2016
Genre:
ISBN:

This thesis presents the first direct search for lepton flavor violating decays of the recently discovered Higgs boson. The search is performed in the $H \rightarrow \mu \tau_{e}$ and $H \rightarrow \mu \tau_{h}$ decay channels, where $\tau_{e}$ and $\tau_{h}$ denote the electronic and hadronic tau decay channels respectively. The search is performed using the proton-proton collisions data gathered at the Compact Muon Solenoid detector at the Large Hadron Collider. The search uses 19.7 fb$^{-1}$ of $\sqrt{s}$ = 8 TeV data taken in 2012 as well as 2.3 fb$^{-1}$ of $\sqrt{s}$ = 13 TeV data taken in 2015. The limits on the branching fraction $B(H\rightarrow \mu\tau)$ are measured, and the existing limits from indirect searches are reduced by an order of magnitude. This thesis also presents a measurement of the differential cross section of a W boson produced in associated with jets. This measurement was performed with 2.5 fb$^{-1}$ of $\sqrt{s}$ = 13 TeV proton-proton collision data produced by the Large Hadron Collider in 2015 and recorded at the Compact Muon Solenoid detector. Cross sections are computed as a function of jet multiplicity, and the results are compared to theoretical predictions from leading order and next-to-leading order Monte Carlo generators.

A Search for Lepton Flavor Violating Decays of the Higgs Boson and a Measurement of W Boson Production Using the CMS Detector at the LHC

A Search for Lepton Flavor Violating Decays of the Higgs Boson and a Measurement of W Boson Production Using the CMS Detector at the LHC
Author:
Publisher:
Total Pages: 109
Release: 2016
Genre:
ISBN:

This thesis presents the first direct search for lepton flavor violating decays of the recently discovered Higgs boson. The search is performed in the $H \rightarrow \mu \tau_{e}$ and $H \rightarrow \mu \tau_{h}$ decay channels, where $\tau_{e}$ and $\tau_{h}$ denote the electronic and hadronic tau decay channels respectively. The search is performed using the proton-proton collisions data gathered at the Compact Muon Solenoid detector at the Large Hadron Collider. The search uses 19.7 fb$^{-1}$ of $\sqrt{s}$ = 8 TeV data taken in 2012 as well as 2.3 fb$^{-1}$ of $\sqrt{s}$ = 13 TeV data taken in 2015. The limits on the branching fraction $B(H\rightarrow \mu\tau)$ are measured, and the existing limits from indirect searches are reduced by an order of magnitude. This thesis also presents a measurement of the differential cross section of a W boson produced in associated with jets. This measurement was performed with 2.5 fb$^{-1}$ of $\sqrt{s}$ = 13 TeV proton-proton collision data produced by the Large Hadron Collider in 2015 and recorded at the Compact Muon Solenoid detector. Cross sections are computed as a function of jet multiplicity, and the results are compared to theoretical predictions from leading order and next-to-leading order Monte Carlo generators.

Search for Doubly Charged Higgs Bosons with Lepton-flavour-violating Decays Involving Tau Leptons

Search for Doubly Charged Higgs Bosons with Lepton-flavour-violating Decays Involving Tau Leptons
Author:
Publisher:
Total Pages: 8
Release: 2007
Genre:
ISBN:

The authors search for pair production of doubly charged Higgs particles (H{sup ±±}) followed by decays into electron-tau (e[tau]) and muon-tau ([mu][tau]) pairs using a data set corresponding to an integrated luminosity of 350 pb−1 collected from {bar p}p collisions at √s = 1.96 TeV by the CDF II experiment. They search separately for cases where three or four final-state leptons are detected, and then combine the results into limits for each exclusive flavor decay mode of the H{sup ±±}. Assuming 100% branching ratios of the H{sup {+-}{+-}} to left-handed e[tau] ([mu][tau]) pairs, they set an H{sup {+-}{+-}} lower mass limit of 114 (112) GeV/c2 at the 95% confidence level (C.L.).