O ensino da Física Moderna e Contemporânea (FMC) vem sendo palco para uma ampla discussão nas últimas décadas. No entanto, a realidade escolar ainda se encontra profundamente afastada de uma prática sistematizada do ensino de tópicos relativos a este período de construção do conhecimento científico. Ao contrário dos argumentos apresentados nos documentos educacionais e nas pesquisas acadêmico-científicas, o que ainda se enxerga é uma prática dominada por tópicos associados à física clássica e enviesada por uma visão de ciência profundamente comprometida com o caráter empírico-indutivista de apreensão da realidade. Neste contexto, esta pesquisa buscou promover uma reflexão sobre a dimensão epistemológica do problema de renovação curricular. Para isto, baseou-se em referenciais das denominadas teorias de currículos, compreendendo a constituição dos saberes escolares segundo as reflexões do sociólogo da educação francês Jean-Claude Forquin, e no trabalho epistemológico do filósofo da ciência francês Gaston Bachelard, acerca da novidade essencial do pensamento científico contemporâneo. Coloca-se como hipótese central que a concepção positivista de ciência, dominante na educação científica, vem exercendo enorme influência sobre a forma como discussões e propostas sobre o ensino da FMC tem sido conduzidas - ocasionando um afastamento cada vez maior entre os estudantes e as formas próprias de pensar deste período de extrema importância para a ciência. Para materialização destas reflexões, foram analisadas diversas propostas para o ensino e divulgação da Física de Partículas Elementares no nível médio, apontando que grande parcela delas vem se concentrando em disseminar uma visão reduzida à enunciação da composição da matéria por quarks e da classificação e organização das espécies de partículas. Apontamos para a necessidade de encontrar alternativas para o ensino de física de partículas, tomando seu desenvolvimento histórico como parâmetro de análise. / The teaching of Contemporary and Modern Physics (CMP) have been the stage for a wide discussion in the past few decades. However, the actual school is far away from a systematized practices on teaching topics related to this period of scientific development of knowledge. Contraty to the arguments presented in the educational documents and academic researches, what we\'ve been seen is a practice dominated by topics of classical physics e skewed by a deeply committed view of Science with an empirical-inductive character of apprehension of reality. In this context, this research sought to promote a reflection on the epistemological dimension of the curriculum renewal problem. For this, it was based on references of the curriculum theories, understading the constitution of scholarly knowledge, according to the work of the French sociologist Jean-Claude Forquin, and on the epistemological work of the French philosopher of Science Gaston Bachelard, on the essential novelty of the contemporary scientific thought. The central hypothesis is that the positivist conception of Science, dominant in the scientific education, has been exerting a strong influence in discussions and proposals about on teaching of the CMP - leading to a great distance between the students and the own ways of thinking of this period of for science. In order to materialize these reflections, several proposals for the teaching and dissemination of Elementary Particle Physics in the middle level were analyzed, pointing out that a large number of them have been concentrating on disseminate a view of particle physics reduced as a composition of matter by quarks and the classification and organization of particles species. We\'re pointing to a necessite of finding alternative looks for particle physics teaching, taking its historical development as a parameter of analysis.

<p>The Standard Model describes all elementary particles known today, but at larger energies it will have to be complemented with new particles and interactions. To be able to distinguish new physics at proton colliders such as LHC at CERN, it is essential to have an appropriate description of the colliding protons and their interactions. The study of the proton is important also in itself, to get a better understanding of the non-perturbative aspects of the strong interaction.</p><p>In paper I-IV of this thesis, a model for the non-perturbative dynamics of quarks and gluons is developed, based on quantum fluctuations in hadrons. The parton distributions of the proton are given by momentum fluctuations, with sea quark distributions generated by fluctuations into baryon-meson pairs. This model can reproduce proton structure function data, as well as measured asymmetries between up and down valence quark distributions and between the anti-up and anti-down sea. It provides an intrinsic charm quark component as indicated by data. It also predicts an asymmetry in the strange sea of the proton, which can explain the NuTeV anomaly first attributed to new physics beyond the Standard Model.</p><p>Charged Higgs bosons are predicted by several theories for new physics, including Supersymmetry. At proton colliders, the predicted dominant production mechanism is in association with top and bottom quarks. In paper V-VII, different contributions to this production are studied, and an algorithm is developed for combining the two dominant processes gb -> tH^+/- and gg -> tbH^+/-. The algorithm gives a smooth transition from small to large transverse momenta of the b-quark, which is important when the b-quark is observed. It also gives arguments for the choice of factorisation scale in the process.</p>

The Standard Model describes all elementary particles known today, but at larger energies it will have to be complemented with new particles and interactions. To be able to distinguish new physics at proton colliders such as LHC at CERN, it is essential to have an appropriate description of the colliding protons and their interactions. The study of the proton is important also in itself, to get a better understanding of the non-perturbative aspects of the strong interaction. In paper I-IV of this thesis, a model for the non-perturbative dynamics of quarks and gluons is developed, based on quantum fluctuations in hadrons. The parton distributions of the proton are given by momentum fluctuations, with sea quark distributions generated by fluctuations into baryon-meson pairs. This model can reproduce proton structure function data, as well as measured asymmetries between up and down valence quark distributions and between the anti-up and anti-down sea. It provides an intrinsic charm quark component as indicated by data. It also predicts an asymmetry in the strange sea of the proton, which can explain the NuTeV anomaly first attributed to new physics beyond the Standard Model. Charged Higgs bosons are predicted by several theories for new physics, including Supersymmetry. At proton colliders, the predicted dominant production mechanism is in association with top and bottom quarks. In paper V-VII, different contributions to this production are studied, and an algorithm is developed for combining the two dominant processes gb -&gt; tH+/- and gg -&gt; tbH+/-. The algorithm gives a smooth transition from small to large transverse momenta of the b-quark, which is important when the b-quark is observed. It also gives arguments for the choice of factorisation scale in the process.

In this thesis, higher derivative theories are investigated. Ostrogradskian instability of higher derivative theories is examined both at the classical and quantum levels. It is shown that avoiding the instability in nondegenerate higher derivative theories is impossible. Moreover, the degenerate model of relativistic particle with a curvature term is studied as a viable higher derivative theory. Most of the work we present here is not original. We give a review of the literature and compile various detached works that already exist.

The lepton flavor violating interactions are worthwhile to examine since they are sensitive to physics beyond the Standard Model. The simplest extension of the Standard Model promoting the lepton flavor violating interactions are the so called two Higgs doublet model which contains an additional Higgs doublet carrying the same quantum numbers as the first one. In this model, the lepton flavor violating interactions are induced by new scalar Higgs bosons, scalar h^0 and pseudo scalar A^0, and Yukawa couplings, appearing as free parameters, are determined by using the experimental data. On the other hand, the possible extra dimensions are interesting in the sense that they ensure a solution to the hierarchy and cosmological constant problems and also result in the enhancement in the physical quantities of various processes. In the present work, we predict the branching ratios of lepton flavor violating radion decays r-&gt / e^+- mu^-+, r-&gt / e^+- tau^-+ and r-&gt / mu^+- tau^-+ in the two Higgs doublet model, including a single extra dimension, in the framework of the Randall Sundrum scenario. We observed that the branching ratios of the processes we study are at most at the order of 10^-8 for the small values of radion mass and it decreases with the increasing values of the radion mass. Among the LFV decays we study, the r-&gt / mu^+- tau^-+ decay would be the most suitable one to measure its branching ratio.

Presented is a search for the rare hadronic B meson decay B0 -&amp;gt; eta phi. It is based on 86 x 10^6 BB pairs recorded by the BABAR experiment at the Stanford Linear Accelerator Center between 1999 and 2002. phi mesons are reconstructed in the channel phi -&amp;gt; K+ K-. eta mesons are reconstructed in the channels eta -&amp;gt; gamma gamma and eta -&amp;gt; pi+ pi- pi0. Signal events are identified by a candidate counting and a maximum-likelihood method. To ensure an unbiased measurement, the number of signal events is blinded throughout the analysis. Although no significant signal is found by either method, the maximum-likelihood method obtains a smaller statistical uncertainty. In this method, the branching fraction of the decay B0 -&amp;gt; eta phi is determined by the upper limit BR (B0 -&amp;gt; eta phi) &amp;lt; 3.28 x 10^-6 (90%). This value includes a systematic uncertainty of 6.2%. The cited upper limit is consistent with recent theoretical predictions. Therefore, this search gives no indication for particle interactions that are not described by the Standard Model of particle physics. / Vorgestellt wird eine Suche nach dem seltenen hadronischen B-Meson-Zerfall B0 -&amp;gt; eta phi. Sie basiert auf 86 x 10^6 BB-Paaren, die zwischen 1999 und 2002 vom BABAR-Experiment am Stanford Linear Accelerator Center aufgezeichnet wurden. phi-Mesonen werden im Kanal phi -&amp;gt; K+ K- rekonstruiert. eta-Mesonen werden in den Kanälen eta -&amp;gt; gamma gamma und eta -&amp;gt; pi+ pi- pi0 rekonstruiert. Zur Identifikation von Signalereignissen wird eine Abzählmethode und eine Maximum-Likelihood-Methode verwendet. Um eine unvoreingenommene Messung zu gewährleisten, bleibt die Anzahl der Signalereignisse während der gesamten Analyse blind. Durch keine der verwendeten Methoden wird ein signifikantes Signal nachgewiesen. Die Maximum-Likelihood-Methode liefert jedoch eine kleinere statistische Unsicherheit. In dieser Methode ist das Verzweigungsverhältnis des Zerfalls B0 -&amp;gt; eta phi durch die obere Grenze BR (B0 -&amp;gt; eta phi) &amp;lt; 3.28 x 10^-6 (90%) gegeben. Dieser Wert enthält eine systematische Unsicherheit von 6.2%. Die angegebene obere Grenze ist mit aktuellen theoretischen Vorhersagen konsistent. Damit gibt diese Untersuchung keine Hinweise auf Wechselwirkungen, die nicht durch das Standardmodell der Elementarteilchenphysik beschrieben werden.

Studies of minimum bias events at colliders probe the behavior of QCD in the non-perturbative regime. The phenomenology of events in this regime is described by empirical models that take many parameters, which all need to be tuned to the observed data. Measurements based on angular correlations between the highest transverse momentum charged particle track and the other charged particle tracks in collision events can, because of their robustness against experimental and detector effects, be a component of the tuning inputs for the models. We measure such observables in a variety of pseudorapidity ranges and at many center-of-mass energies at DØ and ATLAS. We observe that such observables are poorly described by current models and tunes that are used to produce simulated event samples, making them valuable information for the tuning process. The Matrix Element method is a powerful analysis tool to extract precise measurements from data samples of limited statistics. We have investigated the potential of the Matrix Element method to measure the mass of the charged Higgs in the exclusive decay H±→τ±ν→e±+3ν when produced in top quark decays at the Tevatron, with emphasis on the construction of transfer functions in the τ decay chain. We concluded that the τ decay chain can be successfully parametrized via a transfer function and that the method has the potential to provide an accurate charged Higgs mass measurement in this channel. Triggering on τ leptons is a key component for many beyond the Standard Model searches at ATLAS, such as the search for the charged Higgs boson. Events containing Z bosons can be used to measure the efficiency of the ATLAS τ hadronic-decay trigger. We have used a tag-and-probe method on simulated Z boson decays to 2 τ leptons where one decays to a μ while the other decays hadronically. The μ is used as the tag and the τ side is probed. We demonstrated that the efficiency of the τ hadronic-decay trigger can be accurately measured with this method using the first 100 pb-1 of ATLAS data. / Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 732

The LHC at CERN is now undergoing a set of upgrades to increase the center of mass energy for the colliding particles to be able to explore new physical processes. The focus of this thesis lies on the so called phase II upgrade which will preliminarily be completed in 2023. After the upgrade the LHC will be able to accelerate proton beams to such a velocity thateach proton has a center of mass energy of 14 TeV. One disadvantage of the upgrade is that it will be harder for the atlas detector to isolate unique particle collisions since more and more collisions will occur simultaneously, so called pile-up. For 14 TeV there does not exist a full simulation of the atlas detector. This thesis instead uses data from Monte Carlo simulations for the particle collisions and then uses so called smearing functions to emulate the detector responses. This thesis focuses on how a mono-jet analysis looking for different wimp models of dark matter will be affected by this increase in pile-up rate. The signal models which are in focus are those which try to explain dark matter without adding new theories to the standard model or QFT, such as the effective theory D5 operator and light vector mediator models. The exclusion limits set for the D5 operators mass suppression scale at 14 TeV and 1000 fb-1are 2-3 times better than previous results at 8 TeV and 10 fb-1. For the first time limits have been set on which vector mediator mass models can be excluded at 14 TeV.

By using the Kaluza-Klein reduction, the derivation of the maximal supergravities from the D=11 supergravity theory, as well as the Abelian Yang-Mills supergravities from the D=10 type I supergravity theory are discussed. After a thorough review of the symmetric spaces the symmetric space sigma model is studied in detail. The first-order formulation of both the pure and the matter coupled symmetric space sigma model is presented in a general formalism. The dualisation of the non-gravitational Bosonic sectors of the D=11, IIB and the maximal supergravities are also reviewed in a concise but a self-contained formulation. As an example of the dualisation of the matter coupled supergravities, the doubled formalism is constructed for the D=8 Salam-Sezgin supergravity.

Presented is a search for the rare hadronic B meson decay B0 -&amp;gt; eta phi. It is based on 86 x 10^6 BB pairs recorded by the BABAR experiment at the Stanford Linear Accelerator Center between 1999 and 2002. phi mesons are reconstructed in the channel phi -&amp;gt; K+ K-. eta mesons are reconstructed in the channels eta -&amp;gt; gamma gamma and eta -&amp;gt; pi+ pi- pi0. Signal events are identified by a candidate counting and a maximum-likelihood method. To ensure an unbiased measurement, the number of signal events is blinded throughout the analysis. Although no significant signal is found by either method, the maximum-likelihood method obtains a smaller statistical uncertainty. In this method, the branching fraction of the decay B0 -&amp;gt; eta phi is determined by the upper limit BR (B0 -&amp;gt; eta phi) &amp;lt; 3.28 x 10^-6 (90%). This value includes a systematic uncertainty of 6.2%. The cited upper limit is consistent with recent theoretical predictions. Therefore, this search gives no indication for particle interactions that are not described by the Standard Model of particle physics. / Vorgestellt wird eine Suche nach dem seltenen hadronischen B-Meson-Zerfall B0 -&amp;gt; eta phi. Sie basiert auf 86 x 10^6 BB-Paaren, die zwischen 1999 und 2002 vom BABAR-Experiment am Stanford Linear Accelerator Center aufgezeichnet wurden. phi-Mesonen werden im Kanal phi -&amp;gt; K+ K- rekonstruiert. eta-Mesonen werden in den Kanälen eta -&amp;gt; gamma gamma und eta -&amp;gt; pi+ pi- pi0 rekonstruiert. Zur Identifikation von Signalereignissen wird eine Abzählmethode und eine Maximum-Likelihood-Methode verwendet. Um eine unvoreingenommene Messung zu gewährleisten, bleibt die Anzahl der Signalereignisse während der gesamten Analyse blind. Durch keine der verwendeten Methoden wird ein signifikantes Signal nachgewiesen. Die Maximum-Likelihood-Methode liefert jedoch eine kleinere statistische Unsicherheit. In dieser Methode ist das Verzweigungsverhältnis des Zerfalls B0 -&amp;gt; eta phi durch die obere Grenze BR (B0 -&amp;gt; eta phi) &amp;lt; 3.28 x 10^-6 (90%) gegeben. Dieser Wert enthält eine systematische Unsicherheit von 6.2%. Die angegebene obere Grenze ist mit aktuellen theoretischen Vorhersagen konsistent. Damit gibt diese Untersuchung keine Hinweise auf Wechselwirkungen, die nicht durch das Standardmodell der Elementarteilchenphysik beschrieben werden.