Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (p. [115]-119).

Techn. University, Diss., 2007--Darmstadt.

Physics measurements at the LHC rely on the imulation of the proton-proton interaction to estimate detector performance and physics ackgrounds. Therefore, a good understanding of ll the processes involved is crucial to the final precision of any measurement. Monte Carlo event generators try to provide a realistic description of the proton-proton collision by combining the theoretical models describing different stages of the interaction process. Within this framework, the baryon number transport and the hadronisation mechanism are currently described by phenomenological models that need input from experimental data. This thesis investigates these subjects in the unique kinematic region covered by the LHCb detector. The production cross section ratios of identified hadrons (protons, kaons and pions) have been measured as a function of pseudorapidity and transverse momentum both at $sqrt{s} = 0.9$ TeV and $sqrt{s} = 7$ TeV collisions using 320 $mub^{-1}$ and 1.8 $nb^{-1}$ of data respectively. The measurements are then compared to the predictions from several tunings of the PYTHIA Monte Carlo generator. In general, current models do not give a satisfactory description of the hadronisation and tend to underestimate the transport of the baryon number into the final state. Critical to this analysis is the particle identification provided by the LHCb Ring Imaging Cherenkov (RICH) system. To ensure high performance, a proper calibration of the RICH photon detectors response is necessary. A system for the calibration of the magnetic distortion induced by the LHCb dipole magnet onto the photon detectors is described. The system currently provides calibration parameters used in the LHCb event reconstruction software and introduces a critical improvement to the overall particle identification performance.

O Método do Grupo Ressonante (RGM) é um método utilizado no estudo da interação hádron-hádron, na qual não são desprezados os graus de liberdade internos destas partículas. Nesta dissertação estudaremos os efeitos associados `a interação entre um quark pesado Q com outro leve q no potencial de troca de um gluón chamado de One Gluon Exchange Potencial (OGEP), tradicionalmente obtido a partir de um potencial relativístico de interação do modelos de quarks, fazendo uma expansão em potências de momentos nos espinores constituintes (potencial de Fermi-Breit). Faremos uma aproximação semi-relativística para o quark leve q, enquanto que o quark pesado Q será considerado não-relativístico. Este potencial semi-relativístico será usado no RGM para estudar a interação entre charmônios e nucleons como no caso da interação J/ψ-nucleon. / The Resonating Group Method (RGM) is used in hadron-hadron interactions, when internal degrees of freedom of composite particles can’t be neglected. In this dissertation we shall study the effects associated with the interaction between a heavy quark Q with a light quark q, using the the One Gluon Exchange Potential (OGEP) traditionally obtained from a relativistic interaction potential in the quark model, by an expansion in powers of momentum of the constituent spinors (potential Fermi-Breit). We will make a semi-relativistic approach for light quark q, while the heavy quark Q will be considered non-relativistic. This semi-relativistic potential will be used in the RGM to study the interaction between charmonia and nucleons as the case J/ψ-nucleon interaction.

O Método do Grupo Ressonante (RGM) é um método utilizado no estudo da interação hádron-hádron, na qual não são desprezados os graus de liberdade internos destas partículas. Nesta dissertação estudaremos os efeitos associados `a interação entre um quark pesado Q com outro leve q no potencial de troca de um gluón chamado de One Gluon Exchange Potencial (OGEP), tradicionalmente obtido a partir de um potencial relativístico de interação do modelos de quarks, fazendo uma expansão em potências de momentos nos espinores constituintes (potencial de Fermi-Breit). Faremos uma aproximação semi-relativística para o quark leve q, enquanto que o quark pesado Q será considerado não-relativístico. Este potencial semi-relativístico será usado no RGM para estudar a interação entre charmônios e nucleons como no caso da interação J/ψ-nucleon. / The Resonating Group Method (RGM) is used in hadron-hadron interactions, when internal degrees of freedom of composite particles can’t be neglected. In this dissertation we shall study the effects associated with the interaction between a heavy quark Q with a light quark q, using the the One Gluon Exchange Potential (OGEP) traditionally obtained from a relativistic interaction potential in the quark model, by an expansion in powers of momentum of the constituent spinors (potential Fermi-Breit). We will make a semi-relativistic approach for light quark q, while the heavy quark Q will be considered non-relativistic. This semi-relativistic potential will be used in the RGM to study the interaction between charmonia and nucleons as the case J/ψ-nucleon interaction.

Philosophiae Doctor - PhD / The standard model of cosmology (the ɅCDM model) has been very successful and is compatible with all observational data up to now. However, it remains an important task to develop and apply null tests of this model. These tests are based on observables that probe cosmic distances and cosmic evolution history. Supernovae observations use the so-called `standard candle' property of SNIa to probe cosmic distances D(z). The evolution of the expansion rate H(z) is probed by the baryon acoustic oscillation (BAO) feature in the galaxy distribution, which serves as an effective `standard ruler'. The observables D(z) and H(z) are used in various consistency tests of ɅCDM that have been developed. We review the consistency tests, also looking for possible new tests. Then the tests are applied, first using existing data, and then using mock data from future planned experiments. In particular we use data from the recently commissioned Dark Energy Survey (DES) for SNIa. Gaussian Processes, and possibly other non-parametric methods, used to reconstruct the derivatives of D (z) and H (z) that are needed to apply the null tests of the standard cosmological model. This allows us to estimate the current and future power of observations to probe the ɅCDM model, which is the foundation of modern cosmology. In addition, we present an improved model of the HI galaxy number counts and bias from semi-analytic simulations, and we use it to calculate the expected yield of HI galaxies from surveys with a variety of phase 1 and 2 SKA configurations. We illustrate the relative performance of the different surveys by forecasting errors on the radial and transverse scales of the BAO feature. We use the Fisher matrix method to estimate the error bars on the cosmological parameters from future SKA HI galaxy surveys. We find that the SKA phase 1 galaxy surveys will not contend with surveys such as the Baryon Oscillation Spectroscopic Survey (BOSS) whereas the full "billion galaxy survey" with SKA phase 2 will deliver the largest dark energy Figure of Merit of any current or future large-scale structure survey. / South African Square Kilometre Array Project (SKA) and German Academic Exchange Service (DAAD)

O Método do Grupo Ressonante (RGM) é um método utilizado no estudo da interação hádron-hádron, na qual não são desprezados os graus de liberdade internos destas partículas. Nesta dissertação estudaremos os efeitos associados `a interação entre um quark pesado Q com outro leve q no potencial de troca de um gluón chamado de One Gluon Exchange Potencial (OGEP), tradicionalmente obtido a partir de um potencial relativístico de interação do modelos de quarks, fazendo uma expansão em potências de momentos nos espinores constituintes (potencial de Fermi-Breit). Faremos uma aproximação semi-relativística para o quark leve q, enquanto que o quark pesado Q será considerado não-relativístico. Este potencial semi-relativístico será usado no RGM para estudar a interação entre charmônios e nucleons como no caso da interação J/ψ-nucleon. / The Resonating Group Method (RGM) is used in hadron-hadron interactions, when internal degrees of freedom of composite particles can’t be neglected. In this dissertation we shall study the effects associated with the interaction between a heavy quark Q with a light quark q, using the the One Gluon Exchange Potential (OGEP) traditionally obtained from a relativistic interaction potential in the quark model, by an expansion in powers of momentum of the constituent spinors (potential Fermi-Breit). We will make a semi-relativistic approach for light quark q, while the heavy quark Q will be considered non-relativistic. This semi-relativistic potential will be used in the RGM to study the interaction between charmonia and nucleons as the case J/ψ-nucleon interaction.

No description available.

This thesis presents work carried out using data from the LHCb experiment during the first three years of data taking, 2010 - 2012. A study of the effects of radiation damage on the silicon sensors of the LHCb Vertex Locator is performed, with an emphasis on the implications for the long term performance of the detector. Following three years of operation the sensors have received a maximum delivered neutron equivalent fluence of approximately 1.6E12 per square centimeter, leading to a number of radiation induced effects. In particular the change in charge collection efficiency and signal/noise with fluence is compared to theoretical expectations, and the current trends are extrapolated to the fluences expected at the end of the LHCb detector lifetime. The development of an unexpected effect due to the structure of the routing lines in the sensors is described in detail. Searches for lepton flavour and baryon number violating decays of the tau lepton using the 2011 LHCb dataset are described. Observation of any lepton flavour or baryon number violation would be an unambiguous sign of new physics, whilst setting improved limits helps to constrain a number of Beyond the Standard Model theories. First LHCb limits are set on the branching fractions of the decays tau- to mu- mu+ mu-, tau- to anti-proton mu+ mu- and tau- to proton mu- mu-, with these results also representing the first limits on lepton flavour violating tau decays at a hadron collider. The limit on tau- to mu- mu+ mu- is expected to approach the world's best result from Belle in the coming years whilst the tau- to anti-proton mu+ mu- and tau- to proton mu- mu- results constitute the first limits on the branching fractions of these decays. The future prospects for these measurements with further data are briefly described.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21568号 / 理博第4475号 / 新制||理||1642(附属図書館) / 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 青木 慎也, 教授 田中 貴浩, 准教授 髙山 史宏 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM