Correction to Luminosity Measurement for the Pixel Luminosity Telescope at CMS
Correction to Luminosity Measurement for the Pixel Luminosity Telescope at CMS

Author: Krishna Thapa

Publisher:

Published: 2016

Total Pages: 86

ISBN-13:

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The search for and detailed study of new particles and forces with the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) of CERN is fundamentally dependent on the precise measurement of the rate at which proton-proton collisions produce any particles, the so-called luminosity. Therefore, a new detector, the Pixel Luminosity Telescope (PLT), dedicated to measure the luminosity at high precision was added to the CMS experiment in 2015. It measures the inclusive charged particle production from each collision of proton bunches in the LHC. Additional charged particles which are observed by the instrument but produced from sources other than collisions are characterized by measurements of particle trajectories and subtracted from the luminosity. Methods were developed to calculate the corrections to the luminosity measurement of the PLT.

Luminosity Measurement at the Compact Muon Solenoid Experiment of the LHC
Luminosity Measurement at the Compact Muon Solenoid Experiment of the LHC

Author: Olena Karacheban

Publisher: Springer

Published: 2018-06-22

Total Pages: 153

ISBN-13: 3319931393

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This book describes the application of a novel technology for beam instrumentation and luminosity measurement and first results on a cutting edge technology potentially to be used after the upgrade of the Large Hadron Collider to higher luminosity. It presents a unique diamond-based luminometer with a detailed performance study. The online bunch-by-bunch luminosity measurements provide an invaluable feedback to the Collider for beam optimisation and for the understanding of beam dynamics. The precision of the luminosity measurement is crucial for all physics analyses. This book highlights the Van der Meer method, which is used for the calibration of the luminometers of the CMS (Compact Muon Solenoid) experiment, and describes the estimate of systematic uncertainties, e.g. due to radiation damage of sensors and electronics and uncertainties of beam parameters. For the future high-luminosity upgrade of the collider, sapphire sensors are investigated in a test beam. It is demonstrated for the first time that sapphire sensors can be used as single particle detectors. A model for the charge transport in sapphire is developed and successfully applied.

The CMS Pixel Luminosity Telescope Browser Interface
The CMS Pixel Luminosity Telescope Browser Interface

Author: Mark Miller Foerster

Publisher:

Published: 2015

Total Pages: 192

ISBN-13:

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The search for and detailed study of new particles and forces with the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) of CERN is fundamentally dependent on the precise measurement of the rate at which proton-proton collisions produce any particles, the so-called luminosity. For the discovery of the Higgs candidate in 2012 the relative precision of this quantity was about 2.5%. To be able to observe deviations from Standard Model predictions for decay rates of this particle and others which can hint to new phenomena the targeted luminosity uncertainty is about 1%. Therefore, a new device, the pixel luminosity telescope has been built that counts charged collision products close to the LHC beam in real time. The development of the software interface dedicated to control its operation, monitor its activity, and store calibration and configuration information together with data into a database is the subject of this work. The interface was constrained by the need to be suitable for operation by expert as well as non-expert data taking personnel. In addition to operation at the detector level, the interface must also integrate into a framework that simultaneously collects luminosity information from other sub-detectors of CMS. Finally, it had to be built from common and well-tested software tools for reliability and the prospect of long-term availability.

CMS Pixel Detector Upgrade and Top Quark Pole Mass Determination
CMS Pixel Detector Upgrade and Top Quark Pole Mass Determination

Author: Simon Spannagel

Publisher: Springer

Published: 2017-08-01

Total Pages: 286

ISBN-13: 331958880X

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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.

Online Luminosity Measurement at CMS for Energy Frontier Physics After LS1
Online Luminosity Measurement at CMS for Energy Frontier Physics After LS1

Author:

Publisher:

Published: 2015

Total Pages: 2

ISBN-13:

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This proposal was directed towards the measurement of Bunch-by-Bunch and Total Luminosity in the CMS experiment using Single-Crystal Diamond (sCVD) installed close to the Interaction Point - known as the Fast Beam Conditions Monitor, or BCM1F detector. The proposal was successfully carried out and in February 2015 CMS installed its upgraded BCM1F detector. At first collisions in June 2015 the BCM1F was used as the primary luminometer, then in August 2015 a Van De Meer scan has been carried out and the detailed luminometer calibration is under study. In all aspects of performance measurement the upgraded detector has satisfied its design parameters and as an overview of its performance in this report will show, we have high expectations that the detector will be a powerful addition to the luminosity measurement at CMS and LHC. The proposed upgrade of BCM1F was a collaboration of CMS Institutes in Germany (DESY-Zeuthen) and the USA (Princeton) and of CERN itself.

Astrophysics Of Gas Nebulae and Active Galactic Nuclei
Astrophysics Of Gas Nebulae and Active Galactic Nuclei

Author: Donald E. Osterbrock

Publisher: University Science Books

Published: 2006

Total Pages: 488

ISBN-13: 9781891389344

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Thoroughly revised and expanded throughout, the new edition is a graduate-level text and reference book on gaseous nebulae, nova and supernova remnants. Much of the new data and new images are from the Hubble Space Telescope with two wholly new chapters being added along with other new features. The previous edition which was tried and tested for thirty years has now been succeeded by a revised, updated, larger edition, which will be valuable to anyone seriously interested in astrophysics.