This thesis presents an investigation of the charged B meson decay to the pseudoscalar-vector final state p°π±..The results presented in this thesis have been published in Physics Letters B, Volume 542, Issues 3-4, 29 August 2002, Pages 183-192.

Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 163-166).

Thesis (Ph. D.)--University of Hawaii at Manoa, 2003. / On title page "[eta]" appears as Greek symbol and "c̳" is a subscript. Includes bibliographical references (leaves 124-128).

Thesis (Ph. D.)--University of Chicago, Dept. of Physics, March 2003. / Includes bibliographical references. Also available on the Internet.

The hadronic decay D0 → KS pi+ pi- provides direct access to the measurement of the mixing parameters of the neutral charm meson system and allows to test for indirect CP violation. Mixing is a time-dependent phenomenon for which the time evolution of the transition amplitude of a D0 (anti-D0) decay to the final state KS pi+ pi- has to be considered. The parameters driving those time-dependent oscillations are x and y, depending on the masses and widths of the physical eigenstates. The CP violation parameters |q/p| and phi describe the superposition of the flavour eigenstates D0 and anti-D0 and of the physical eigenstates D1 and D2. By measuring the time- and phase-space dependent distribution of D0 → KS pi+ pi- decays, the mixing parameters can be extracted and a search for indirect CP violation can be performed. This thesis reports a measurement of the mixing parameters and the preparations of a measurement of the CP violation parameters on data collected with the LHCb experiment in 2011 and 2012, corresponding to an integrated luminosity of 3/fb. The D0 and anti-D0 mesons are required to originate from a semileptonic decay of a B meson. The parameters of interest are extracted from a fit in D0 decay time and the Dalitz variables. The phase-space distribution of D0 → KS pi+ pi- decays is modelled by expressing the three-body decay as a succession of two-body decays. The decay amplitude of a D0 or anti-D0 meson into KS pi+ pi- final state is a superposition of all possible intermediate resonances and the single resonances interfere with each other across the phase-space.

According to the Big Bang Theory, matter and antimatter were produced in equal amounts at the beginning. Over time the antimatter disappeared, leaving galactic struc- tures composed only of matter. Therefore, there is some process in nature that proceeds at different rates for matter and antimatter due to the violation of the CP symmetry. CP violation has been observed in strange and bottom quark meson decays. However, a direct CP violation is predicted in the τ lepton sector. Specifically, the charge asymmetry due to CP violation in the decay τ − → π−K0S (≥ 0π0) ντ is predicted to be (+0.33 ± 0.01)%. In this work the charge asymmetry of the decay τ − → π−K0S (≥ 0π0) ντ is measured using a dataset of 437 million τ lepton pairs collected by the BABAR experiment at the SLAC Na- tional Accelerator Laboratory. The charge asymmetry induced by CP violation is found to be A = (−0.45 ± 0.24 ± 0.11) %, consistent with prediction. / Graduate

We investigate several problems in relativity and particle physics where symmetries play a central role; in all cases geometric properties of Lie groups and their quotients are related to physical effects. The first part is concerned with symmetries in gravity. We apply the theory of Lie group deformations to isometry groups of exact solutions in general relativity, relating the algebraic properties of these groups to physical properties of the spacetimes. We then make group deformation local, generalising deformed special relativity (DSR) by describing gravity as a gauge theory of the de Sitter group. We find that in our construction Minkowski space has a connection with torsion; physical effects of torsion seem to rule out the proposed framework as a viable theory. A third chapter discusses a formulation of gravity as a topological BF theory with added linear constraints that reduce the symmetries of the topological theory to those of general relativity. We discretise our constructions and compare to a similar construction by Plebanski which uses quadratic constraints. In the second part we study CP violation in the electroweak sector of the standard model and certain extensions of it. We quantify fine-tuning in the observed magnitude of CP violation by determining a natural measure on the space of CKM matrices, a double quotient of SU(3), introducing different possible choices and comparing their predictions for CP violation. While one generically faces a fine-tuning problem, in the standard model the problem is removed by a measure that incorporates the observed quark masses, which suggests a close relation between a mass hierarchy and suppression of CP violation. Going beyond the standard model by adding a left-right symmetry spoils the result, leaving us to conclude that such additional symmetries appear less natural.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18063号 / 理博第3941号 / 新制||理||1568(附属図書館) / 30921 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 中家 剛, 准教授 市川 温子, 教授 鶴 剛 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

[pt] A partir do século passado descobrimos a existência de antipartículas e, desde então, a busca por entender a assimetria entre partícula e antipartículas tem sido um forte campo de pesquisa na física. Dentre as condições que possibilitam a assimetria matéria-antimatéria no Universo, está o fenômeno da Violação de Carga-Paridade (VCP). Devido à ela observamos diferenças entre os processos decaimento de uma partícula e sua antipartícula. Tal fenômeno tem efeitos importantes para mésons formados pelos quarks b ou s, porém as predições deste efeito para o setor de charme são muito pequenas, com assimetrias de CP em torno da ordem de 10−3 ou menores. De fato, apenas recentemente a VCP foi observada em decaimentos de 2 corpos de mésons D0. Esta dissertação discute duas estratégias na busca por VCP no canal D+ → π−π+π+ utilizando dados do experimento LHCb durante o Run II. O método de busca por VCP, método Mirandizing, consiste em computar estatisticamente as populações de D+ e D− em intervalos do espaço de fase bidimensional, calculando a significância da diferença dessas populações. Para amostras de grande estatística, como é o nosso caso, o objetivo final é aplicar um método alternativo que consiste em obter o número das populações através de ajustes de massa para cada intervalo. Este trabalho tem como objetivo realizar a validação do método. Nossa estratégia é realizar os procedimentos dividindo a amostra de forma aleatória em duas sub-amostras e não separando nas amostras de D+ e D−. O que se espera, então, são resultados que demonstrem compatibilidade estatística entre as duas amostras. Além dessa validação utilizando os dados, vamos, também, realizar o mesmo procedimento em 100 pseudo-experimentos. Adicionalmente, realizamos os estudos de sensibilidade a fim de verificar em quais possíveis cenários a VCP poderia ser observada nesse canal, dado o tamanho da amostra total. Para este estudo, obteremos o número das populações através da contagem direta (método Mirandizing) dos eventos do espaço de fase dentro da região de massa de maior com maior concentração de eventos de sinal. / [en] Last century we discovered the existence of antiparticles, and since then the search to understand the asymmetry between particles and antiparticles has been a strong field of research in physics. Among the conditions that make matter-antimatter asymmetry possible in the Universe is the Charge-Parity Violation (CPV) phenomenon. Due to it we observe differences between the decay processes of a particle and its antiparticle. Such a phenomenon has important effects for mesons formed by b or s quarks, but the predictions of this effect for the charm sector are very small, with CP asymmetries around the order of 10−3 or smaller. In fact only recently has CPV been observed in 2-body decays of D0 mesons. This dissertation presents the validation of strategies in the search for CPV in the D+ → π−π+π+ channel using data from the LHCb experiment during Run II. The CPV search method, the so-called Mirandizing method, consists of statistically computing the populations of D+ and D− in intervals of the two-dimensional phase space, obtaining the significance of the difference of these populations. For large statistical samples, as is our case, the ultimate goal is to apply an alternative method by obtaining the number of the populations through mass fits for each interval. This work aims to perform the validation of the method. Our strategy is to perform the procedure by dividing the sample randomly into two subsamples, but not separating into the D+ and D− samples. What is expected, then, is that the results demonstrate statistical compatibility between the two samples. In addition to this validation using data, we will also perform the same procedure on 100 pseudo-experiments. Finally, we perform sensitivity studies in order to verify the possible scenarios in which CPV could be observed in this channel, given the total sample size. For this study, we will obtain the number of the populations by directly counting the phase space events (Mirandizing) within the mass region with the highest concentration of signal events.

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