CMS Pixel Detector Upgrade and Top Quark Pole Mass Determination
Title | CMS Pixel Detector Upgrade and Top Quark Pole Mass Determination PDF eBook |
Author | Simon Spannagel |
Publisher | Springer |
Pages | 286 |
Release | 2017-08-01 |
Genre | Science |
ISBN | 331958880X |
This thesis addresses two different topics, both vital for implementing modern high-energy physics experiments: detector development and data analysis. Providing a concise introduction to both the standard model of particle physics and the basic principles of semiconductor tracking detectors, it presents the first measurement of the top quark pole mass from the differential cross-section of tt+J events in the dileptonic tt decay channel. The first part focuses on the development and characterization of silicon pixel detectors. To account for the expected increase in luminosity of the Large Hadron Collider (LHC), the pixel detector of the compact muon solenoid (CMS) experiment is replaced by an upgraded detector with new front-end electronics. It presents comprehensive test beam studies conducted to verify the design and quantify the performance of the new front-end in terms of tracking efficiency and spatial resolution. Furthermore, it proposes a new cluster interpolation method, which utilizes the third central moment of the cluster charge distribution to improve the position resolution. The second part of the thesis introduces an alternative measurement of the top quark mass from the normalized differential production cross-sections of dileptonic top quark pair events with an additional jet. The energy measurement is 8TeV. Using theoretical predictions at next-to-leading order in perturbative Quantum Chromodynamics (QCD), the top quark pole mass is determined using a template fit method.
Top-Quark Pair Production Cross Sections and Calibration of the Top-Quark Monte-Carlo Mass
Title | Top-Quark Pair Production Cross Sections and Calibration of the Top-Quark Monte-Carlo Mass PDF eBook |
Author | Jan Kieseler |
Publisher | Springer |
Pages | 172 |
Release | 2016-06-15 |
Genre | Science |
ISBN | 3319400053 |
This thesis presents the first experimental calibration of the top-quark Monte-Carlo mass. It also provides the top-quark mass-independent and most precise top-quark pair production cross-section measurement to date. The most precise measurements of the top-quark mass obtain the top-quark mass parameter (Monte-Carlo mass) used in simulations, which are partially based on heuristic models. Its interpretation in terms of mass parameters used in theoretical calculations, e.g. a running or a pole mass, has been a long-standing open problem with far-reaching implications beyond particle physics, even affecting conclusions on the stability of the vacuum state of our universe. In this thesis, this problem is solved experimentally in three steps using data obtained with the compact muon solenoid (CMS) detector. The most precise top-quark pair production cross-section measurements to date are performed. The Monte-Carlo mass is determined and a new method for extracting the top-quark mass from theoretical calculations is presented. Lastly, the top-quark production cross-sections are obtained – for the first time – without residual dependence on the top-quark mass, are interpreted using theoretical calculations to determine the top-quark running- and pole mass with unprecedented precision, and are fully consistently compared with the simultaneously obtained top-quark Monte-Carlo mass.
First Measurement of the Running of the Top Quark Mass
Title | First Measurement of the Running of the Top Quark Mass PDF eBook |
Author | Matteo M. Defranchis |
Publisher | Springer Nature |
Pages | 170 |
Release | 2022-01-03 |
Genre | Science |
ISBN | 3030903761 |
In this thesis, the first measurement of the running of the top quark mass is presented. This is a fundamental quantum effect that had never been studied before. Any deviation from the expected behaviour can be interpreted as a hint of the presence of physics beyond the Standard Model. All relevant aspects of the analysis are extensively described and documented. This thesis also describes a simultaneous measurement of the inclusive top quark-antiquark production cross section and the top quark mass in the simulation. The measured cross section is also used to precisely determine the values of the top quark mass and the strong coupling constant by comparing to state-of-the-art theoretical predictions. All the theoretical and experimental aspects relevant to the results presented in this thesis are discussed in the initial chapters in a concise but complete way, which makes the material accessible to a wider audience.
Top Quark Mass Measurement in the Lepton+jets Channel Using Full Simulation of the CMS Detector
Title | Top Quark Mass Measurement in the Lepton+jets Channel Using Full Simulation of the CMS Detector PDF eBook |
Author | Stefan Kasselmann |
Publisher | |
Pages | 130 |
Release | 2007 |
Genre | |
ISBN |
Study of the Inclusive Beauty Production at CMS and Construction and Commissioning of the CMS Pixel Barrel Detector
Title | Study of the Inclusive Beauty Production at CMS and Construction and Commissioning of the CMS Pixel Barrel Detector PDF eBook |
Author | Lea Caminada |
Publisher | Springer Science & Business Media |
Pages | 159 |
Release | 2012-02-23 |
Genre | Science |
ISBN | 3642245617 |
This thesis describes one of the first measurements at the CERN LHC -- the world's largest and highest-energy particle collider. The CMS collision data is analyzed, and results in the first measurement of the inclusive b cross section using semileptonic decays at a center of mass energy of 7 TeV.
Packaging and Assembly Technologies for the Pixel Detector Upgrade and Measurement of Ττ Final States with the CMS Experiment at the LHC
Title | Packaging and Assembly Technologies for the Pixel Detector Upgrade and Measurement of Ττ Final States with the CMS Experiment at the LHC PDF eBook |
Author | Fabio Colombo |
Publisher | |
Pages | |
Release | 2016 |
Genre | |
ISBN |
Packaging and Assembly Technologies for the Pixel Detector Upgrade and Measurement of Final States with the CMS Experiment at the LHC
Title | Packaging and Assembly Technologies for the Pixel Detector Upgrade and Measurement of Final States with the CMS Experiment at the LHC PDF eBook |
Author | |
Publisher | |
Pages | |
Release | 2016 |
Genre | |
ISBN |