A thesis presented in fulfillment of the requirements for the degree of: Master of Science in Physics, University of the Witwatersrand, Johannesburg, 2017 / Tile Online software is a set of Trigger and Data Acquisition (TDAQ) required for the operation of Tile. It is built on top of ATLAS TDAQ software following AT LAS management tools and policies. The TDAQ software has been migrated from CMT to CMake, and from SVN to Git, in favor of modern software development tools and procedures. Since Tile Online software follows ATLAS TDAQ, there was a need of reorganization, simplification and clean-up of Tile Online software packages. Tile Online software packages have been migrated and reorganized to the newest ATLAS TDAQ release and the outcome is now used at Point-1 with success. The diagnostic and verification system (DVS) is part of the ATLAS TDAQ online software packages used for configuring and executing tests for TDAQ com ponents, and for advising recovery actions to the TDAQ operator/user. A wrapper way to start complex Tile DVS tests that required two separate programs to run on separate computers has been implemented and tests can now be run from a graphical user interface with detailed presentation of the results by non-experts. The upgrade of the Large Hadron Collider (LHC) to the High-Luminosity LHC will provide significant opportunities to explore new physics beyond the Standard Model. This however presents significant challenges to the detector and the TDAQ systems. The Tile Calorimeter will undergo upgrades whereby the current readout electronics will be completely redesigned and replaced in phase-II to cope with the increased luminosity imposed by the HL-LHC. / XL2018

No description available.

Using a new and unique multiparticle detection device, we have measured the average final state multiplicity for a sample of 1,500 events from the reaction pp → pp (nw<super>±</super>) at 28.5 GeV/c where both protons were constrained to limited regions of phase space. We find that the resulting average charge multiplicity depends linearly on the recoil mass from both protons, and on the inelasticity. A rapidity analysis indicates that low multiplicity final states are produced by one fragmenting proton, while as the multiplicity increases, so does the probability of the other proton also fragmenting. No evidence was found for multiperipheral production. We compare our data with events in which only one proton is constrained and find that the multiplicity varies with the behavior of both final state protons, the higher multiplicities occurring for more central collisions. / Ph. D.

This thesis describes the measurement of inclusive heavy flavor jet suppression in collisions between two lead nuclei with the center of mass energy per nucleon-nucleon pair of 2.76 TeV with the ATLAS detector at the Large Hadron Collider (LHC). The measurement of the heavy flavor jets and b-jet quenching at the LHC is important in the path towards the understanding of QGP. Parton showers initiated by heavy quarks are expected to be sensitive to the medium in a different way as the large quark mass suppresses the medium-induced radiation. This results in a different interplay between radiative and collisional energy loss. Therefore the analysis of the properties of jet associated with b hadrons (b-jet) is useful in understanding energy loss in the QGP. The inclusive b-jet suppression R AA has been measured using muons in jets, where a b-jet corresponds to a jet with at least one muon clustered with the anti-k t algorithm with parameter R = 0.2. The b-jets of p T between 30 GeV - 150 GeV are identified by the semileptonic decay of beauty hadrons. Muons originating from background sources, primarily Charm hadrons, pion and kaon decays, have been removed from the analysis using template fits to the distribution of a quantity(p T^rel) capable of statistically distinguishing between signal and background. The measured nuclear modification factor R AA has been presented in different centrality bins as a function of the b-jet transverse momentum p T.The results of R AA indicate that the yield of the most central event (0-10%) experiences more suppression compared to the most peripheral event (60-80%) by a factor of approximate 2.

Thesis (Ph. D.)--University of Oregon, 2004. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 254-261). Also available for download via the World Wide Web; free to University of Oregon users.

Includes bibliographical references (p. 10). / "Physics and Mathematics" -t.p. "TID-4500 (15th Ed.)" -t.p.

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (p. 153-161).

No description available.

A wide array of cosmological and astrophysical observations support the existence of dark matter. More precisely, temperature anisotropy measurements of the cosmic microwave background (CMB) estimate that the current dark matter mass density is about five times that of the visible Universe. However, the nature of dark matter is not yet understood, inspiring numerous theoretical candidates. One popular candidate is the weakly-interacting massive particles or WIMPs that interact with standard model particles on the electroweak scale and could have the correct relic abundance today. Experiments such as XENON1T and XENONnT are designed to search for WIMPs on Earth using the dual-phase liquid xenon Time Projection Chamber (LXeTPC) technology. The XENON1T experiment operated until Dec. 2018 and had made the world-leading upper limits for WIMP-nucleus interactions at the time. Its successor, the XENONnT experiment, has been commissioned since 2021 and has taken data for its first science run. This thesis presents the commissioning data and the first science-run data analysis. This thesis describes an essential facet of the XENON1T and XENONnT experiments: how, step by step, the most elementary signals of single photons are reconstructed into events. Each event represents a particle interaction in the detector, including those from rare physical processes. This includes several technical developments with signal processing and simulation software that enable accurate reconstruction of signals and precisely evaluate the effect of various types of remaining miss-reconstruction. Furthermore, this thesis will present two analyses developed to search for rare events in XENON1T, only possible with an accurate and precise understanding of the event reconstruction. One is to search for ⁸𝐁 Solar neutrino events via 𝐂𝐄𝜈𝐍𝐒 process and low mass WIMPs by characterizing reconstruction efficiency and additional background at a lower energy threshold. The spin-independent DM-nucleus interaction is improved in the mass range between 3𝐆𝐞𝐕𝑐² and 11𝐆𝐞𝐕𝑐² by as much as an order of magnitude from the previous world-leading result, using data from the XENON1T experiment. The other is the search for the neutrinoless double-beta decay at its 𝑄-value, 𝑄_𝛽𝛽 = (2457.83$\pm$0.37)\,keV. The analysis demonstrated that the relative energy resolution at one 𝝈/𝝁 is as low as (0.80±$0.02) % in its one-ton fiducial mass, and for single-site interactions at 𝑄_𝛽𝛽, a world-leading resolution in 𝐋𝐗e experiment that enhance the experimental sensitivity to the neutrinoless double-beta decay events.

In 1982 Fermilab experiment E623 took data in a search for high-mass boson resonances which decay into one or two ɸ mesons produced in 400 GeV/c proton-nuclei interactions. A hardware trigger selected 3.6 million events with identified K⁺K⁻ pairs. Here I report my study of events with ɸKπ in the final state and present the first evidence for K°*(2060) decaying into ɸKπ and ɸK°*(890). / Ph. D. / incomplete_metadata