Physics & Astronomy ETDs

Publication Date

7-12-2014

Abstract

To discover and probe the properties of new particles, we need to collide highly energetic particles. The Tevatron at Fermilab has collided protons and anti-protons at very high energies. These collisions produce short lived and stable particles, some known and some previously unknown. The CDF detector is used to study the products of such collisions and discover new elementary particles. To study the interaction between high energy charged particles and the detector materials often requires development of new instruments. Thus this dissertation involves a measurement at a contemporary experiment and development of technologies for related future experiments that will build on the contemporary one. Using data from proton-antiproton collisions at sqrt(s) = 1.96 TeV recorded by the CDF II detector at the Fermilab Tevatron, evidence for the excited resonance state Lambda_b^*0 is presented in its Lambda_b0 pi^(+)pi^(-) decay, followed by the Lambda_b^0 -> Lambda_c^(+) pi^(-) and Lambda_c^(+) -> pK^(-) pi^(+) decays. The analysis is based on a data sample corresponding to an integrated luminosity of 9.6 fb^(−1) collected by an online event selection process based on charged particle tracks displaced from the proton-antiproton interaction point. The significance of the observed signal is 3.5 sigma. The mass of the observed state is found to be 5919.22 ± 0.76 MeV/c^(2) in agreement with similar findings in proton-proton collision experiments. To predict the radiation damage to the components of new particle tracking detectors, prototype devices are irradiated at test beam facilities that reproduce the radiation conditions expected. The profile of the test beam and the fluence applied per unit time must be known. We have developed a technique to monitor in real time the beam profile and fluence using an array of pin semiconductor diodes whose forward voltage is linear with fluence over the fluence regime relevant to, for example, silicon tracking detectors in the LHC upgrade era. We have demonstrated this technique in the 800 MeV proton beam at the LANSCE facility of Los Alamos National Laboratory.

Degree Name

Physics

Level of Degree

Doctoral

Department Name

Physics & Astronomy

First Advisor

Seidel, Sally

Second Advisor

Gorelov, Igor

First Committee Member (Chair)

Rizatdinova, Flera

Second Committee Member

Allahverdi, Rouzbeh

Third Committee Member

Bitteker, Leo

Language

English

Keywords

Collider Detector at Fermilab, Resonance State

Document Type

Dissertation

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