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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

A search for new diboson resonances in the boosted semi-leptonic final state at √s = 13 TeV with the ATLAS detector

Carbone, Ryne Michael January 2017 (has links)
A search is presented for new resonances decaying to a pair of boosted Standard Model bosons, WV, where the W boson decays leptonically (W → lν, with l = e, µ) and the other weak boson, V (V=W,Z), decays hadronically (V → qq¯ 0/qq¯, with q, q0 = u, d, c, s, b). The data were collected with the ATLAS detector at the CERN Large Hadron Collider, during the 2015 and 2016 periods of pp collisions, at a center-of-mass energy √s = 13 TeV, and correspond to a total integrated luminosity of 36.1 fb^−1. The hadronic decay of the boosted $V$ boson is reconstructed as a single large-radius jet, and the leptonic decay of the W boson is reconstructed as a lepton and missing transverse energy. The search is sensitive to resonances produced with quark-antiquark fusion, gluon-gluon fusion, and vector-boson fusion. No significant excesses are observed above the Standard Model background prediction. Upper limits on production cross section times branching ratio to WV are set at a 95 % confidence level for selected benchmark signal models. Models of a neutral, narrow scalar boson (spin-0), charged and neutral vector bosons (spin-1) coupling to the Standard Model gauge bosons, and a neutral Randall-Sundrum bulk graviton (spin-2) are considered. The search significantly improves the limits produced in recent searches.
182

Precise beta spectrometry using a Ge(HP) detector in a magnetic field

Hetherington, Donald Wordsworth. January 1984 (has links)
No description available.
183

A search for the rare decay of a charged B meson into a charged K meson, a neutrino and an anti-neutrino /

Harnois-Déraps, Joachim. January 2006 (has links)
No description available.
184

Level structure of ¹⁵²Gd populated in ¹⁵²Tb β decay

Stapels, Christopher John 20 September 2004 (has links)
As part of a research program to study the transitional region of N=88 isotones, ¹⁵²Tb was produced by the reaction ¹⁵¹Eu(α,3n)¹⁵²Tb in the 88" cyclotron located at LBNL. Gamma-ray spectroscopy of the radiation emitted from excited ¹⁵²Gd following the β⁺ decay of ¹⁵²Tb has been performed using an array of 20 germanium detectors. The large Q-value (3990 keV) of the ¹⁵²Tb 2⁻ decay allows for the population of many levels; study of coincidence and single events resulted in the establishment of 54 new levels and 266 new transitions. Angular correlation of the coincidences has determined spin and parity of many levels with several seen as key to the band structure, including two new 0⁺ levels. One new rotational band including the new 1475.2 keV 0⁺ level and the 1771.7 keV 2⁺ level is proposed. The overall band structure compared to collective excitation models demonstrates the position of ¹⁵²Gd in the transition from a spherical to deformed shape, also seen in other N=88 isotones. Monopole transition strength among bands indicates the possibility of mixing of both shapes among the excited states. The remarkable similarity of the band structure among these isotones is discussed. / Graduation date: 2005
185

Fundamental solutions for wave equation in de Sitter model of universe

Yagdjian, Karen, Galstian, Anahit January 2007 (has links)
In this article we construct the fundamental solutions for the wave equation arising in the de Sitter model of the universe. We use the fundamental solutions to represent solutions of the Cauchy problem and to prove the Lp − Lq-decay estimates for the solutions of the equation with and without a source term.
186

Staden som dött två gånger- en analys av Pompeji och dess bevarande

Hembjer, Pernilla January 2013 (has links)
This essay concerns the site of Pompeii and its preservation. The aim is to investigate what causes the decay of the ruins, how to prevent it and what consequences the tourism has on the site. The material consists of interviews with three Swedish scientists who are currently working with documenting a block in Pompeii. The result reveals a large number of threats against the city, such as climate, tourism and an inadequate economy situation. Examples of solutions are more investments which can be used for restorations and reconstructions, and guards to prevent vandalism. Another alternative is to stop the preservation work and let the ruins decay.
187

Z decays in the light gluino and light bottom squark scenario /

Luo, Zumin. January 2003 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Physics, December 2003. / Includes bibliographical references. Also available on the Internet.
188

Measurement of (Vub) using inclusing semileptonic B meson decays

Kim, Hojeong 28 August 2008 (has links)
Not available / text
189

Novel Roles for Ribonucleic Acids in Programmed Cell Death

Thomas, Marshall Peter 01 June 2015 (has links)
Apoptosis is a tightly coordinated program to shut down and dismantle a cell, characterized by mitochondrial outer membrane permeabilization (MOMP), caspase activation to cleave hundreds of proteins, DNA fragmentation, and blocked translation. Little is known about the fate of RNA as cells die, even though apoptosis has been intensively studied for decades. Here I show that mRNAs, but not noncoding RNAs (ncRNAs), are rapidly and globally degraded during apoptosis. The decay occurs in many cell types responding to diverse apoptotic stimuli. mRNA decay is triggered early in apoptosis, preceding membrane lipid scrambling, genomic DNA fragmentation and modifications to translation initiation factors that might cause translational arrest. mRNA decay depends on MOMP and is amplified by effector caspase activity. 3' truncated mRNA decay intermediates with nontemplated uridylate-rich tails are generated during apoptosis and degraded by the 3' to 5' exonuclease DIS3L2. Knockdown of DIS3L2 reduces apoptotic mRNA decay and partially rescues cell death. I propose that global mRNA decay is a new hallmark of apoptosis caused by the concerted action of several nucleases. I also report a new role for RNA and DNA in directing cytotoxic leukocyte proteases to their substrates. When cytotoxic lymphocytes recognize and attack infected or cancerous cells, they deliver the granzyme (Gzm) serine proteases into the target cell. The Gzms cleave diverse protein substrates to orchestrate cell death. RNA binding proteins are highly enriched in unbiased proteomic screens of Gzm protein substrates. I hypothesized that the Gzms are guided to nucleic acid binding protein targets via direct binding to RNA or DNA. Using fluorescence polarization, I show that the Gzms and related leukocyte proteases bind to RNA and DNA with low nanomolar affinity. Nucleic acid binding by the Gzms facilitates their cleavage of RNA and DNA binding proteins, and guides them into target cell nuclei and onto neutrophil extracellular traps. Nucleic acid binding provides an elegant mechanism to confer protease substrate specificity for cleavage of nucleic acid-binding proteins that play essential roles in cellular gene expression and cell proliferation.
190

From atoms to astronomy : new approaches in neutrino physics

Jerkins, Melissa Travis 14 December 2010 (has links)
In this thesis I present research in neutrino physics utilizing tools from both atomic physics and astrophysics. Recent advances in atomic physics enable a new type of beta decay experiment to measure the absolute mass scale of the neutrino using a sample of ultracold atomic tritium. These initial conditions enable the detection of the helium ion in coincidence with the beta. I construct a two-dimensional fit incorporating both the shape of the beta spectrum and the direct reconstruction of the neutrino mass peak. I present simulation results of the feasible limits on the neutrino mass achievable in this new type of tritium beta decay experiment. The same advances in atomic physics that enable the creation of an atomic source for tritium beta decay also suggest a new method of achieving large-scale isotope separation. Multiple experiments that are investigating the absolute mass scale of the neutrino through neutrinoless double beta decay could benefit from this new technique, which applies generally to many elements, including the double beta emitter Nd-150 that is particularly difficult to separate in large quantities. The method is based on an irreversible change of the mass-to-magnetic moment ratio of a particular isotope in a supersonic atomic beam, followed by a magnetic multipole whose gradients deflect and guide the atoms. I present numerical simulations of isotope separation for a range of examples and demonstrate that large-scale isotope separation should be possible using ordinary inexpensive magnets and the existing technologies of supersonic beams and lasers. Additionally I report results from a search for low-multiplicity neutrino bursts in the Sudbury Neutrino Observatory (SNO). Such bursts could indicate detection of a nearby core-collapse supernova explosion. The data were taken from November 1999 to May 2001 when the detector was filled with heavy water (Phase I), as well as data from July 2001 to August 2003 when NaCl was added to the detector (Phase II). The search was a blind analysis in which the potential backgrounds were estimated and analysis cuts were developed to eliminate such backgrounds with 90% confidence before the data were examined. The search maintained a greater than 50% detection probability for standard supernovae occurring at a distance of up to 60 kpc for Phase I and up to 70 kpc for Phase II. No low-multiplicity bursts were observed during the data-taking period. / text

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