No description available.

The angle γ, with an uncertainty of approximately 10° is the least well constrained angle of the unitary triangle. Better experimental constraints on this parameter are required in order to provide a consistency check on the standard model description of CP violation. A promising strategy for measuring γ involves exploiting interference effects present in B^± → DK^± decays where the D subsequently decays to a three or four body final state. The three body decay D → K_S ⁰p⁺p^- and the four body decay D⁰ → K⁺K^-p⁺p^- are suitable candidates for making such a measurement. However independent knowledge of the decay structure of these decays is required. The impact of the model, used to describe the p⁺p^- S wave, in the D⁰ → K⁺K^-p⁺p^- decay, on the uncertainty in the measurement of γ is estimated via a simulation study. It is determined that the uncertainty on a gamma measurement would be compromised by this model uncertainty within one year of LHCb data running. The four body decay D⁰ → K⁺K^-p⁺p^- also provides a candidate for making a γ measurement. This decay is expected to display a rich resonant structure. An understanding of this decay may also provide an insight into low energy QCD in addition to allowing a search for CP violation. Only one previous amplitude analysis has been performed on this decay. Using data collected at the CLEO-II.V, CLEO-III and CLEO-c experiments an amplitude model is developed for the D⁰ → K⁺K^-p⁺p^- decay. This model is qualitatively similar to that produced in the previous analysis although the model presented in this thesis considers higher orbital angular momentum states and distinguishes between conjugate states that the previous model did not. A search for CP violation is also carried out using the D⁰ → K⁺K^-p⁺p^- decay data. A positive confirmation of CP violation at the level of sensitivity provided by this decay data would provide evidence for a level of CP violation which could not be accounted for within the standard model. No significant evidence for CP violation is observed in this decay. A toy MC study was carried out in order to determine the sensitivity to γ which may be achieved using this decay. In this study, sets of 1000 B⁺ and B^- events are generated and the decay model developed for the D → K⁺K^-p⁺p^- decay is used to describe the D decay. The sensitivity to γ determined in this study is 11°.

Title: EMG analysis of lower limb muscles in dependence on growing muscle fatigue Objectives: The main objective of this thesis is monitor and evaluate changes in EMG parameters of muscles of low extremities depending on the level of local muscle fatigue (during exercise on legpress. Methods: Study included 8 subjects who completed the exercise on weight lifting machine legpress, while we were measuring 6 muscles on lower extremities by using surface EMG. The measuremets was at level 75 % of maximum weight, when probands doing exercises until he had complete muscle fatigue. Data from electromyography was processed and through them we could watched the spectral distribution of the EMG signal and changes of EMG amplitude, which we relate to maximal voluntary contraction. Results: After analysis of all 48 measured muscles, increased of EMG amplitude occured in 45 of them. There was 67 % statistically significant, another 6 % was really close to significant level and remaining 23 % was insignificant. We have 144 time series in analysis of quartile milestones (Q25, Q50 and Q75). From this number decrease of frequency occured 135 times. There was 75 % statistically significant. Then we found out that biggest decreased was in median and mainly in Q75, it was in 82 %. Conclusions: Study proved that during...

Title: EMG analysis of lower limb muscles in dependence on growing muscle fatigue Objectives: The main objective of this thesis is monitor and evaluate changes in EMG parameters of muscles of low extremities depending on the level of local muscle fatigue (during exercise on legpress). Methods: Study included 8 subjects who completed the exercise on weight lifting machine legpress, while we were measuring 6 muscles on lower extremities by using surface EMG. The measuremets was at level 75 % of maximum weight, when probands doing exercises until he had complete muscle fatigue. Data from electromyography was processed and through them we could watched the spectral distribution of the EMG signal and changes of EMG amplitude. Key words: amplitude analysis, spectral analysis, surface polyelectromyography, muscle fatigue

Title: Discrimination of EMG signals from individual forearm muscles from surface EMG Abstract: Location of electrodes for sensing the forearm muscles using surface electromyography is not accurately described. It is based only on recommendations by various authors in making researches. The aim of this study was to determine the optimal placement of electrodes on the forearm and describe it to another repeatable measurements. By analyzing the amplitude of EMG recording is confirmed not only the optimal location of electrodes, but either suggested muscle synergies that are possible to analyze more deeply in other studies because a detailed examination of muscle synergies are considerable application in upper limb prosthetics Keywords: Surface electromyography, forearm muscles, amplitude analysis

This thesis documents two studies of the neutral charm meson system using the LHCb detector, and gives an overview of the numerous changes made to the LHCb software trigger in advance of Run 2 of the LHC. In the first analysis, amplitude models are applied to studies of the resonance structure in D⁰ → K⁰_SK^−π⁺ and D⁰ → K⁰_SK⁺π^− decays using proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb^−1, collected during Run 1 of the LHC. Relative magnitude and phase information is determined, and coherence factors and related observables are computed for both the whole phase space and a restricted region of 100 MeV/c² around the K*(892)^± resonance. Two formulations for the Kπ S-wave are used, both of which give a good description of the data. The ratio of branching fractions B (D⁰→ K⁰_SK⁺π^−) /B (D⁰→ K⁰_SK^−π⁺) is measured to be 0.655 ± 0.004 (stat) ± 0.006 (syst) over the full phase space and 0.370 ± 0.003 (stat) ± 0.012 (syst) in the restricted region. A search for CP violation is performed using the amplitude models and no significant effect is found. Predictions from SU(3) flavour symmetry for K*(892)K amplitudes of different charges are compared with the amplitude model results, and marginal agreement is found. The second study estimates the sensitivity to D⁰–D⁰ mixing and indirect CP violation parameters that can be achieved using a model-independent technique and the samples of D⁰→ K⁰_SK⁺K^− decays recorded by LHCb in Run 1 and Run 2 of the LHC. These studies show that constraints on these parameters could be significantly improved by an analysis of the anticipated Run 2 dataset.

No description available.

[pt] O presente trabalho de tese é destinado ao estudo do decaimento do méson D+ KS(pi)−(pi)+(pi)+ com dados coletados pelo experimento FOCUS do Fermilab. O estado final, composto por 4 mésons pseudo- escalares, pode ser alcançado através de uma considerável variedade de sub- estruturas ressonantes. O proposito da análise é encontrar quais são estes possíveis canais intermediários através de suas contribuições e fases relativas. Para tanto, é utilizado o formalismo de Análise de Amplitudes usando o chamado Modelo Isobárico. A dinâmica do decaimento é definida através de uma função que contém as características (formas funcionais das ressonâncias, distribuição angular, etc) dos canais que intervêm no decaimento e cujo domínio é um espaço o de fase determinado por 5 invariantes (devido às restrições de decaimento em quatro corpos sem spin). A função é então ajustada ao conjunto de dados coletados. Nos resultados, verificamos uma grande contribuição do méson vetor-axial a1(1260) (52%) seguido do vetor-axial K1(1400) (34%). Além disso, o modelo apresenta contribuição da ressonância (sigma) (cerca de 8%, vinda de a1(sigmapi)KS e sigmaKSpi) e uma razoável contribuição da ressonância escalar K− (14%). O estado K já foi visto em seu modo neutro em outros decaimentos de charme, porém ainda não em seu modo carregado. Não encontramos contribui ção significativa do decaimento direto em 4 corpos (não- ressonante). Esta tese vem se somar ao esforço no entendimento da dinâmica das intera ções fortes a baixas energias, que nos últimos anos tem ganhado da física de mésons charmosos uma importante contribuição. / [en] This thesis is devoted to the study of the decay D+ KS(pi)− (pi)+(pi)+ with data collected from the FOCUS experiment, at Fermilab. The final state composed of 4 pseudo-scalars can be produced through a number of resonant sub-structures. The purpose of this analysis is to find the contributing intermediate states by measuring their relative strenghts and phases. For that, the Amplitude Analysis formalism is used, with the so-called Isobar Model. The decay dynamics is described through a function which has the features of the contributing channels (functional forms of the resonances, angular distribution, etc) and which domain is a phase space determined by 5 invariants (due to the kinematical constraints of a 4- body spinless decay). The data sample is thus fitted to this function. Our results show a dominant contribution of the axial- vector meson a1(1260) (52%), followed by the K1(1400) axial-vector (34%). Moreover, the model presents a contribution from the sigma meson (about 8% as a1(sigmapi)KS and sigmaKSpi) and a significant contribution from the scalar k−. The k state has been reported in its neutral mode in other charm decays but not is its charged mode. We find no significant contribution from the direct 4-body decay (non-resonant). This work adds to the effort in the understanding of the strong-interaction dynamics at low energies, which in recent years have been receiving an important contribution from charm meson physics.

Dans cette thèse sont présentées plusieurs études relatives aux désintégrations de mésons Bd et Bs en trois corps sans charme avec un KS dans l'état final.Ces analyses portent sur des données collectées par l'expérience LHCb durant le Run I du LHC, et qui correspondent à une luminosité intégrée de 3 fb-1.Une première analyse consiste à la mesure des rapports d'embranchements des modes B(d,s) -> KSh+h'-, ou h(') désigne un kaon ou un pion.Les mesures précédemment effectuées par LHCb de ces rapports d'embranchement, relativement à celui du mode Bd->KSpi+pi-, sont actualisées.Le but principal de cette analyse est la recherche du mode Bs -> KSK+K-, qui n'a jamais encore été observé.Les rapports d'embranchements, relativement à celui de Bd -> KSpi+pi-, sont mesurés : B(Bs->KSpi+pi-)/B(Bd->KSpi+pi-) = 0.26 +/- 0.04(stat.) +/- 0.02(syst.) +/- 0.01(f_s/f_d) B(Bd->KSKpi)/B(Bd->KSpi+pi-) = 0.17 +/- 0.02(stat.) +/- 0.00(syst.) B(Bs->KSKpi)/B(Bd->KSpi+pi-) = 1.84 +/- 0.07(stat.) +/- 0.02(syst.) +/- 0.04(f_s/f_d) B(Bd->KSKK)/B(Bd->KSpi+pi-) = 0.59 +/- 0.02(stat.) +/- 0.01(syst.)Une première observation de Bs->KSK+K-, correspondant à une significance globale de 3.7 sigmas, est effectuée.Une analyse du plan de Dalitz indépendante du temps et sans étiquetage de saveur du canal Bd -> KSK+K- est effectuée en utilisant l'approche isobare.Les rapports d'embranchement des désintégration quasi-deux-corps des canaux Bd->KS phi, Bd->KS f'2(1525) et Bd->KS chic0 sont mesurés.Ils sont compatibles avec des mesures précédentes effectuées par Babar. / This dissertation presents several studies of the decays of both Bd and Bs mesons to charmless three-body final states including a KS meson.They use the data recorded by the LHCb experiment during Run I of LHC, corresponding to an integrated luminosity of 3 fb-1.A first analysis consists of the measurement of the branching fractions of B(d,s)->KSh+h'- decays, where h(') designates a kaon or a pion.Preceding LHCb measurements of branching fractions for all decay channels, relative to that of Bd->KSpi+pi-, are updated.Furthermore, the primary goal of this analysis is to search for the, as yet, unobserved decay Bs->KSK+K-.The relative branching fractions are measured to be: B(Bs->KSpi+pi-)/B(Bd->KSpi+pi-) = 0.26 +/- 0.04(stat.) +/- 0.02(syst.) +/- 0.01(f_s/f_d) B(Bd->KSKpi)/B(Bd->KSpi+pi-) = 0.17 +/- 0.02(stat.) +/- 0.00(syst.) B(Bs->KSKpi)/B(Bd->KSpi+pi-) = 1.84 +/- 0.07(stat.) +/- 0.02(syst.) +/- 0.04(f_s/f_d) B(Bd->KSKK)/B(Bd->KSpi+pi-) = 0.59 +/- 0.02(stat.) +/- 0.01(syst.) A first observation of Bs->KSK+K- is reported with a global significance of 3.7 sigmas.A flavour-untagged, time-independent Dalitz-plot analysis of Bd->KSK+K- is presented, using the isobar approach.The quasi-two-body branching fractions of Bd->KS phi, Bd->KS f'2(1525), and Bd->KS chic0 are measured.They are compatible with previous measurements from Babar.

[pt] Apesar de ser considerada uma teoria de sucesso no campo das partículas e interações fundamentais, o Modelo Padrão é considerado incompleto porque ainda deixa uma série de questões em aberto. Para abordar algumas delas, é necessário estudar processos tais como decaimento de partículas. Em particular, os decaimentos de hádrons pesados, como os mésons D e B, podem ser sensíveis à física além do Modelo Padrão, como novas fontes de violação de carga-paridade e novas interações. No entanto, com massas na faixa de poucos GeV, onde os cálculos perturbativos da cromodinâmica quântica são limitados, modelos fenomenológicos são necessários para descrever seus decaimentos hadrônicos. Nesta dissertação, um estudo da dinâmica de decaimento de 3 corpos do canal Ds+ em K−K+K+ é apresentado pela primeira vez e utiliza duas abordagens fenomenológicas para descrever a amplitude do decaimento: o Modelo Isobárico e a chamada Quasi-Model Independent Partial Wave Analysis (QMIPWA). As amostras utilizadas correspondem aos dados coletados na run 2 do experimento LHCb (entre os anos 2016-2018) com colisões prótonpróton a uma energia de centro de massa de 13 TeV. A análise é realizada após um processo de seleção para reduzir o background, levando a uma amostra final com cerca de 100 mil decaimentos. Para realizar a análise de amplitudes no Dalitz plot do decaimento, o background remanescente e a eficiência ao longo do gráfico de Dalitz são parametrizados. No caso em que a amplitude de decaimento é descrita pelo Modelo Isobárico, os resultados obtidos mostram uma dominância da ressonância phi(1020) e uma composição de ressonâncias escalares, f0(980) como a mais clara, sendo formada como estados intermediários, e uma pequena mas não desprezível contribuição das ressonâncias de spin-2. O Modelo Isobárico oferece uma descrição qualitativa da dinâmica de decaimento, mas não fornece um ajuste de boa qualidade, mesmo quando uma variedade de possíveis estados intermediários são adicionados ao modelo de amplitude. Por outro lado, o QMIPWA como ferramenta para descrever o setor escalar revelou-se difícil para a região de massa K−K+ acima de 1.3 GeV e sensível às ressonâncias de spin mais alto adicionadas ao modelo, tornando difícil e menos confiável a interpretação dos resultados obtidos. Ainda com as limitações encontradas nos dois modelos, a análise apresentada aqui representa um passo importante para o entendimento da dinâmica deste decaimento, abrindo caminho para estudos com maior estatística no run 3 do LHCb. / [en] Despite of being considered a successful theory in the field of fundamental particles and interactions, the Standard Model is considered incomplete because it still leaves a number of open questions. In order to address some of these, it is necessary to study physical processes such as particle decays. In particular, the decays of heavy hadrons such as D and B mesons can be sensitive to physics beyond the Standard Model, such as new sources of charge-parity violation and new interactions. Nevertheless, at masses at the few GeV range, where perturbative calculations of quantum chromodynamics are limited, phenomenological models are needed to describe their hadronic decays. In this dissertation, a study of the 3-body decay dynamics of the Ds+ to K-K+K+ channel is presented for the first time and uses two phenomenological approaches to describe the decay amplitude: the Isobar Model and the Quasi-Model Independent Partial Wave Analysis (QMIPWA). The samples used corresponds to the data collected in Run 2 of the LHCb experiment (between the years 2016-2018) with proton-proton collisions at a center-of-mass energy of 13 TeV. The analysis is performed after a selection process to reduce background, leading to a final sample of about 100 thousand decays. To perform the amplitude analysis fit to the Dalitz plot of the decay, the remaining background and the efficiency across the Dalitz plot are parametrized. In the case of the Isobar Model, the results obtained show a dominance of the phi(1020) resonance and a composition of scalar resonances, f0(980) as the most clear one, being formed as intermediate states, and a small but not negligible contribution of spin-2 resonances. The Isobar Model offers a qualitative description of the decay dynamics but does not provide a good quality fit, even when a variety of possible intermediate states are added to the amplitude model. On the other hand, the QMIPWA as a tool to describe the scalar sector revealed itself difficult for the region of K−K+ mass above 1.3 GeV and sensitive to the higher-spin resonances added to the model, making it difficult and less reliable to interpret the results obtained. Even with the limitations found through both models, the analysis presented here represent an important step towards the understanding of the dynamics of this decay, opening the path to further studies with higher statistics in run 3 of LHCb.