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Cross section measurement of simultaneously produced Υ(1S) + J/Ψ mesons and upgrade studies for the CMS detector

A measured cross section of simultaneously produced Υ(1S) and J/ψ mesons is performed using 20 fb-1 integrated luminosity in proton-proton collisions at √s=8 TeV center of mass energy recorded by the CMS detector. Both mesons are fully reconstructed from their final states, μ+ μ-. To extract the signal yield, an extended maximum likelihood fit is used on two (invariant mass of Υ(1S) and J/ψ) and three (invariant mass of Υ(1S) and J/ψ, cτ) dimensional components. A two-dimensional extended likelihood fit is used for the signal yield of data and a three-dimensional extended likelihood fit is used to know the possibility of displaced J/ψ candidate events arising from a B meson decay. A data embedding method is used to correct the efficiency in the data. The cross section in the fiducial region, defined as |y|<2.0, is determined to be 16.5±3.6(stat)±2.6(syst) pb.
In order to improve the physics measurements capabilities for the harsh radiation environments at Large Hadron Collider (LHC), radiation hard detectors are needed. Secondary Emission Method (SEM) is a technique to measure the energy of particles such as e, n, and p in extreme radiation environments. Secondary Emission Ionization Calorimetry is a new technique for high radiation conditions. We designed two different types of test boards to test Hamamatsu single anode R7761 and multi-anode R5900-00-M16 PMTs and compared average gain values for both SE and PMT modes. We found that both values (SE and PMT) were comparable, which means the test boards that were developed perform very well and they could be used at Fermilab Test Beam Facility or in the CERN H2 beam area for the detection of minimum ionizing and showering particles.

Identiferoai:union.ndltd.org:uiowa.edu/oai:ir.uiowa.edu:etd-6416
Date01 January 2016
CreatorsDilsiz, Kamuran
ContributorsNachtman, Jane M.
PublisherUniversity of Iowa
Source SetsUniversity of Iowa
LanguageEnglish
Detected LanguageEnglish
Typedissertation
Formatapplication/pdf
SourceTheses and Dissertations
RightsCopyright © 2016 Kamuran Dilsiz

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