Decays of neutral D mesons to final states containing K + π's could provide evidence for CP-violation from a source not accounted for in the Standard Model. Due to the interference between Cabibbo-favored and Cabibbo-suppressed transitions, a decay rate asymmetry of D0 → K0S π0 compared to D0 → K0Lπ0 has been predicted to be non-zero. If New Physics interferes in doubly Cabibbo-suppressed D decays, the measurement of this asymmetry would differ from the predicted value and may provide evidence for CP-violation beyond the CKM mechanism. I present an analysis method to measure this branching fraction asymmetry, R(D0) ≡ B(D0→K0S π0)−B(D0→K0L π0)/(B(D0→K0Sπ0)+B(D0→K0Lπ0)), utilizing e+e− → cc events in the Belle dataset. / Doctor of Philosophy / The Universe appears to be made almost entirely of matter rather than antimatter; however, matter and antimatter should have been created in equal amounts in the Big Bang. We do not know exactly why we observe so much more matter as compared to antimatter. The Standard Model (SM) of particle physics accounts for some of the asymmetry through Charge-Parity (CP) symmetry violation, which explains how particles behave differently than their corresponding antiparticles. In the current state of the SM, some CP-violation is allowed in decays via the weak force, but the theory does not account for enough CP violation to explain the amount of matter-antimatter asymmetry observed in the Universe. Decays of a D meson to a kaon (K meson) plus one or more pions (π mesons) via a new mechanism beyond the weak force could provide evidence of a new source of CP-violation. In this analysis, I present a method for analyzing the decays of neutral D mesons to a neutral kaon and a neutral pion in the Belle dataset to test the SM.

Com o objetivo de investigar a fotoprodução de kaons na região de energias intermediarias, foram realizadas medidas de seção de choque de fotoprodução de híperons utilizando o deutério como alvo, entre 0,50 e 2,95GeV. Para obtenção das medidas foi utilizado o acelerador de elétrons do TJNAF (Thomas Jefferson National Accelerator Facility) localizado na Virginia, USA. Foram obtidas seções de choque de fotoprodução para as reações gama(p, K+)lambda, gama(p, K+)sigmaº, sigma(n, K+)lambda-. Observou-se a estrutura de interferência na proximidade do limiar de produção de \'lambdaº, previsto teoricamente. As seções de choque obtidas foram comparadas com o modelo teórico existente fornecendo informações fundamentais para uma elaboração teórica mais consistente. Foram ainda, observados lambda(1385) com grande resolução abrindo possibilidade de realizar um estudo muito interessante desta produção. / Kaon photoproduction on deuterium was investigated and the differential cross sections were determined using the data obtained in Hall B at TJNAF (Thomas Jefferson National Accelerator Facility). Real photons were produced in the range covered from 0.50 to 2.95GeV. The cross section for kaon production reactions gama(p, K+ ) lambda, gama(p, K+ ) \'sigmaº, sigma(n, K+)lambda- were obtained. The interference structure near the production of lambdaº, predicted theoretically, was revealed. Theoretical model was compared to the cross section obtained and fundamental informations became available in order to improve the consistence of the model existent. At last, lambda(1385) were identified with good resolution conducting to interesting investigation in the future.

This thesis reports two measurements performed using proton-proton collision data collected by the LHCb detector in 2011 and 2012, corresponding to an integrated luminosity of 3 inverse femtobarn and centre-of-mass energies of 7 and 8 TeV respectively. The first measures the CP asymmetry in Bs-anti-Bs oscillations, called asls. This is measured in inclusive Bs and anti-Bs to Ds mu nu X decays, where the Ds meson is reconstructed in the final state K K pi. The measurement is performed in three regions in the Dalitz phase space of the Ds decay, and corrected for detection and background asymmetries. A value of asls = (0.39 +/- 0.26(stat) +/- 0.20(syst))% is found, which is the world's most precise measurement of a CP asymmetry in B meson mixing and is consistent with the Standard Model prediction. The second measurement determines the production asymmetry of Ds mesons, and probes non-perturbative QCD models. It is performed in bins of transverse momentum and pseudorapidity in the kinematic region 2.5.

The PANDA experiment is planned as part of the extended GSI facility FAIR to investigate hadronic reactions in antiproton-proton annihilations. An excellent beam quality and high luminosity is expected which allows the investigation of hadronic reactions such as the spectroscopy of the charmonium system. To ensure different studies of hadronic systems an universal detector is being designed, the PANDA detector. A high resolution Micro Vertex Detector (MVD), as part of the whole setup, is an important component of the track and vertex reconstruction. A mayor part of this work were simulation studies to investigate the resolution ability of the vertex detector. For this the development and implementation of reconstruction algorithms and their integration to the track and vertex reconstruction were an essential part to allow the detailed study of the resolution of the MVD and the whole apparatus under realistic assumptions. The track and vertex reconstruction ability of the detector is shown exemplarily for the channels antiproton-proton into two charged pions and into J/psi and photon. The expected hadronic background for physics observables requires a high selection power of the experimental setup, especially for the investigation of the charmonium system above the DD(bar) threshold. For this particular energy region no experimental data exist and the PANDA experiment can contribute to understand the binding of charmed mesonic systems. Charmonium states can decay to open-charm channels which provide a clear signature in the detector from the charged D-Meson decays. In this work the high selection ability of the experimental setup was investigated for two reaction channels. Under the assumption of an expected low reaction cross section the clear identification of the DD(bar) decay channel was shown, even for the presence of a huge hadronic background. This allows a clear identification of the DD(bar) decay channel and mayor background resources for this channel were discussed. / Das PANDA Experiment wird Teil der geplanten Ausbaustufe FAIR als Erweiterung zur GSI und wird die Untersuchung von hadronischen Reaktionen in Antiproton-Proton Annihilationen ermöglichen. Durch die zu erwartende exzellente Strahlqualität und hohe Luminosität ergeben sich vielfältige Möglichkeiten zur Untersuchung von Hadronenwechselwirkungen, wie beispielsweise die genaue Spektroskopie des Charmoniumsystems. Um vielfältige Untersuchungen verschiedenster hadronischer Systeme zu gewährleisten, wurde der Aufbau eines universellen Detektors geplant, des PANDA Detektors. Dazu ist ein hochauflösender Vertexdetektor (MVD) eine wichtige Komponente, um im Zusammenspiel mit weiteren Detektorkomponenten zur Spur- und Vertexrekonstruktion beitragen zu können. Im Rahmen dieser Arbeit wurden detaillierte Simulationen durchgeführt, die das Auflösungsvermögen des Vertexdetektors charakterisieren, ganz besonders im Hinblick auf die Rekonstruktion verschiedener physikalischer Kanäle. Dafür war die Entwicklung und Implementierung von Algorithmen zur Rekonstruktion der zu erwartenden Detektordaten und deren Integration in den Spurfit zur Teilchenrekonstruktion eine Grundvoraussetzung. Dadurch ist es möglich das Auflösungsvermögen des MVD und des gesamten experimentellen Aufbaus unter realistischen Bedingungen zu testen und zu optimieren. Die Spur- und Vertexrekonstruktion wird anhand der Kanäle Antiproton-Proton nach zwei geladenen Pionen und nach J/Psi Photon evaluiert. Der zu erwartende hadronische Untergrund stellt hohe Anforderungen an die Selektionskraft des experimentellen Aufbaus, bezüglich der physikalischen Observablen, dar. Dies ist besonders für die Untersuchung des Charmoniumsystems oberhalb der DD(quer)-Schwelle von Bedeutung, wofür kaum experimentelle Untersuchungen vorliegen und der PANDA Detektor zukünftig einen entscheidenden Beitrag zum Verständnis gebundener mesonischer Systeme beitragen kann. Zuständen im Charmoniumsystem ist es erlaubt in Open-Charm-Kanäle zu zerfallen, die eine eindeutige experimentelle Signatur mittels der D-Zerfälle in geladene Teilchen im Detektor erlauben. Im Rahmen dieser Arbeit konnte anhand zweier grundlegender Reaktionen gezeigt werden, dass selbst unter ungünstigen Annahmen über den zu erwartenden Wirkungsquerschnitt, der noch nicht schwellennah vermessen wurde, das stark unterdrückte Signal gegenüber Untergrundereignissen hinreichend angereichert werden kann. Dies erlaubt eine klare Identifizierung des DD(quer)-Ausgangskanales, wobei die wesentlichen Untergrundbeiträge identifiziert und diskutiert werden.

BABAR is a particle physics experiment at the Stanford Linear Accelerator Center (SLAC). The purpose of BABAR is to study matter-antimatter asymmetry in the bottom quark system. At SLAC, electons and positrons collide, which annihilate and decay into a variety of daughters. An Upsilon(4S) meson is one of the possible daughters. An Upsilon(4S) decays into a B meson and an anti-B meson more than 96% of the time. A B meson has an anti-bottom quark and an anti-B meson has a bottom quark. The purpose of this thesis is to measure how many Upsilon(1S) originated from Upsilon(4S) in the entire BABAR data set. This thesis compares on-peak data and off-peak data. On-peak data was taken at center of mass energy 10.58GeV. One of the possible interactions is e+e− -> Upsilon(4S) since the mass of Upsilon(4S) is 10.58GeV/c^2. On-peak data, taken at center of mass energy 10.54GeV, is not enough to have any BB pairs because 10.54GeV is less than the mass of an Upsilon(4S). This thesis can be useful for BABAR physicist because it helps set an upper limit on how many BB pairs there are in the entire BABAR data set. In other words, it sets an upper limit on how much more than 96% does Upsilon(4S) decay to BB. Measurement of the decay of Upsilon(4S) -> Upsilon(1S) + X give evidence for non-BB decays of the Upsilon(4S). The final results of this study show that there were (110 +- 3) × 10^5 Upsilon(1S) on-peak, of which (10 +- 9) × 10^5 originated from an Upsilon(4S). Increasing the centre of mass energy from 10.54GeV to 10.58GeV increases the Upsilon(1S) production by (10 +- 8)%.

Com o objetivo de investigar a fotoprodução de kaons na região de energias intermediarias, foram realizadas medidas de seção de choque de fotoprodução de híperons utilizando o deutério como alvo, entre 0,50 e 2,95GeV. Para obtenção das medidas foi utilizado o acelerador de elétrons do TJNAF (Thomas Jefferson National Accelerator Facility) localizado na Virginia, USA. Foram obtidas seções de choque de fotoprodução para as reações gama(p, K+)lambda, gama(p, K+)sigmaº, sigma(n, K+)lambda-. Observou-se a estrutura de interferência na proximidade do limiar de produção de \'lambdaº, previsto teoricamente. As seções de choque obtidas foram comparadas com o modelo teórico existente fornecendo informações fundamentais para uma elaboração teórica mais consistente. Foram ainda, observados lambda(1385) com grande resolução abrindo possibilidade de realizar um estudo muito interessante desta produção. / Kaon photoproduction on deuterium was investigated and the differential cross sections were determined using the data obtained in Hall B at TJNAF (Thomas Jefferson National Accelerator Facility). Real photons were produced in the range covered from 0.50 to 2.95GeV. The cross section for kaon production reactions gama(p, K+ ) lambda, gama(p, K+ ) \'sigmaº, sigma(n, K+)lambda- were obtained. The interference structure near the production of lambdaº, predicted theoretically, was revealed. Theoretical model was compared to the cross section obtained and fundamental informations became available in order to improve the consistence of the model existent. At last, lambda(1385) were identified with good resolution conducting to interesting investigation in the future.

The PANDA experiment is planned as part of the extended GSI facility FAIR to investigate hadronic reactions in antiproton-proton annihilations. An excellent beam quality and high luminosity is expected which allows the investigation of hadronic reactions such as the spectroscopy of the charmonium system. To ensure different studies of hadronic systems an universal detector is being designed, the PANDA detector. A high resolution Micro Vertex Detector (MVD), as part of the whole setup, is an important component of the track and vertex reconstruction. A mayor part of this work were simulation studies to investigate the resolution ability of the vertex detector. For this the development and implementation of reconstruction algorithms and their integration to the track and vertex reconstruction were an essential part to allow the detailed study of the resolution of the MVD and the whole apparatus under realistic assumptions. The track and vertex reconstruction ability of the detector is shown exemplarily for the channels antiproton-proton into two charged pions and into J/psi and photon. The expected hadronic background for physics observables requires a high selection power of the experimental setup, especially for the investigation of the charmonium system above the DD(bar) threshold. For this particular energy region no experimental data exist and the PANDA experiment can contribute to understand the binding of charmed mesonic systems. Charmonium states can decay to open-charm channels which provide a clear signature in the detector from the charged D-Meson decays. In this work the high selection ability of the experimental setup was investigated for two reaction channels. Under the assumption of an expected low reaction cross section the clear identification of the DD(bar) decay channel was shown, even for the presence of a huge hadronic background. This allows a clear identification of the DD(bar) decay channel and mayor background resources for this channel were discussed. / Das PANDA Experiment wird Teil der geplanten Ausbaustufe FAIR als Erweiterung zur GSI und wird die Untersuchung von hadronischen Reaktionen in Antiproton-Proton Annihilationen ermöglichen. Durch die zu erwartende exzellente Strahlqualität und hohe Luminosität ergeben sich vielfältige Möglichkeiten zur Untersuchung von Hadronenwechselwirkungen, wie beispielsweise die genaue Spektroskopie des Charmoniumsystems. Um vielfältige Untersuchungen verschiedenster hadronischer Systeme zu gewährleisten, wurde der Aufbau eines universellen Detektors geplant, des PANDA Detektors. Dazu ist ein hochauflösender Vertexdetektor (MVD) eine wichtige Komponente, um im Zusammenspiel mit weiteren Detektorkomponenten zur Spur- und Vertexrekonstruktion beitragen zu können. Im Rahmen dieser Arbeit wurden detaillierte Simulationen durchgeführt, die das Auflösungsvermögen des Vertexdetektors charakterisieren, ganz besonders im Hinblick auf die Rekonstruktion verschiedener physikalischer Kanäle. Dafür war die Entwicklung und Implementierung von Algorithmen zur Rekonstruktion der zu erwartenden Detektordaten und deren Integration in den Spurfit zur Teilchenrekonstruktion eine Grundvoraussetzung. Dadurch ist es möglich das Auflösungsvermögen des MVD und des gesamten experimentellen Aufbaus unter realistischen Bedingungen zu testen und zu optimieren. Die Spur- und Vertexrekonstruktion wird anhand der Kanäle Antiproton-Proton nach zwei geladenen Pionen und nach J/Psi Photon evaluiert. Der zu erwartende hadronische Untergrund stellt hohe Anforderungen an die Selektionskraft des experimentellen Aufbaus, bezüglich der physikalischen Observablen, dar. Dies ist besonders für die Untersuchung des Charmoniumsystems oberhalb der DD(quer)-Schwelle von Bedeutung, wofür kaum experimentelle Untersuchungen vorliegen und der PANDA Detektor zukünftig einen entscheidenden Beitrag zum Verständnis gebundener mesonischer Systeme beitragen kann. Zuständen im Charmoniumsystem ist es erlaubt in Open-Charm-Kanäle zu zerfallen, die eine eindeutige experimentelle Signatur mittels der D-Zerfälle in geladene Teilchen im Detektor erlauben. Im Rahmen dieser Arbeit konnte anhand zweier grundlegender Reaktionen gezeigt werden, dass selbst unter ungünstigen Annahmen über den zu erwartenden Wirkungsquerschnitt, der noch nicht schwellennah vermessen wurde, das stark unterdrückte Signal gegenüber Untergrundereignissen hinreichend angereichert werden kann. Dies erlaubt eine klare Identifizierung des DD(quer)-Ausgangskanales, wobei die wesentlichen Untergrundbeiträge identifiziert und diskutiert werden.

We study the masses of the low-lying charm and bottom mesons within the framework of heavy-hadron chiral perturbation theory. We work to third order in the chiral expansion, where meson loops contribute. In contrast to previous approaches, we use physical meson masses in evaluating these loops. This ensures that their imaginary parts are consistent with the observed widths of the D-mesons. The lowest odd- and even-parity, strange and non-strange mesons provide enough constraints to determine only certain linear combinations of the low-energy constants (LECs) in the effective Lagrangian. We comment on how lattice QCD could provide further information to disentangle these constants. Then we use the results from the charm sector to predict the spectrum of odd- and even-parity of the bottom mesons. The predicted masses from our theory are in good agreement with experimentally measured masses for the case of the odd-parity sector. For the even-parity sector, the $B$-meson states have not yet been observed; thus, our results provide useful information for experimentalists investigating such states. The near degeneracy of nonstrange and strange scalar $B$ mesons is confirmed in our predictions using $\mathrm{HHChPT}$. Finally,we show why previous approaches of using $\mathrm{HHChPT}$ in studying the mass degeneracy in the scalar states of charm and bottom meson sectors gave unsatisfactory results. Interactions between these heavy mesons are treated using effective theories similar to those used to study nuclear forces. We first look at a strongly-interacting channel which produces a bound or virtual state and a dimer state which couples weakly to a weakly-interacting channel to produce a narrow resonance. We also look at the short-range interactions in two channels. We consider two cases: two channels where one has a strong $s$-wave interaction which produces bound or virtual states, and a dimer state which couples weakly to weakly-coupled channels which in turn can produce narrow resonances. For each of these systems, we use well-defined power-counting schemes. The results can be used to investigate resonances in the charmonium and bottomonium systems. We demonstrate how the method can be applied to the $X(3872)$. The widths of the $X(3872)$ for decay processes to $\bar{D}^0 D^{*0}$ and $\bar{D}^0D^0\pi$ are calculated. We use these results to obtain the line shapes of the $X(3872)$ under different assumptions about the nature of this state.

This thesis presents first measurements of moments of the hadronic n_X^2 distribution measured in inclusive semileptonic decays of B mesons to final states containing a charm quark, B->Xc l nu. The variable n_X^2 is a combination of the invariant mass of the charmed meson m_X, its energy in the B-meson rest-frame E_X, and a constant \tilde{\Lambda} = 0.65 GeV, n_X^2 = m_X^2 c^4 - 2 \tilde{\Lambda} E_X + \tilde{\Lambda}^2. The moments <n_X^k> with k=2,4,6 are measured as proposed by theory to constrain assumptions made in the theoretical description of inclusive observables in semileptonic B-meson decays. This description uses Heavy Quark Expansion (HQE), an effective QCD combined with an Operator Product Expansion. The measurement is based on a sample of 231.6 million e+e- -> Y(4S) -> B\bar{B} events recorded with the BABAR experiment at the PEP-II e+e--storage rings at SLAC. We reconstruct the semileptonic decay by identifying a charged lepton in events tagged by a fully reconstructed hadronic decay of the second B meson. Correction procedures are derived from Monte Carlo simulations to ensure an unbiased measurement of the moments of the n_X^2 distribution. All moments are measured requiring minimum lepton momenta between 0.8 GeV/c and 1.9 GeV/c in the rest frame of the B meson. Performing a simultaneous fit to the measured moments <n_X^k> up to order k=6 combined with other measurements of moments of the lepton-energy spectrum in decays B->Xc l nu and moments of the photon-energy spectrum in decays B->Xs gamma, we determine the quark-mixing parameter |V_{cb}|, the bottom and charm quark masses, the semileptonic branching fraction BR(B->X l nu), and four non-perturbative heavy quark parameters. Using HQE calculations in the kinetic scheme up to order 1/m_b^3 we find |V_{cb}| = (41.65 +- 0.43 +- 0.40 +- 0.58) x 10^{-3} and m_b = (4.570 \pm 0.033 \pm 0.043)GeV/c^2, where the first uncertainty refers to experimental contributions, the second to uncertainties in the HQE, and the third to theoretical uncertainties in the calculations of the semileptonic decay rate. All obtained results are consistent with previous determinations. The inclusion of the moments <n_X^6> decreases the uncertainty on the HQE parameters mu_{pi} and rho_{D}. Furthermore, the theoretical treatment of higher order corrections in the HQE used for the moments <m_X^k> has been verified with these new measurements.

In this master’s thesis the width of the <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Ceta'" /> meson is studied as a function of temperature. We consider a background medium consisting of a pion gas and assume a vanishing net baryon chemical potential. The width is obtained in the framework of large <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?N_%7Bc%7D" /> chiral perturbation theory and we consider terms up to next-to-leading order in the effective Lagrangian. We use a low-density approximation to calculate the width increase due to scattering with pions from the heat bath. The results suggest that the in-medium width for the <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Ceta'" /> may become of considerable size: at a temperature <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?T%5Capprox%2075" /> MeV we find a width increase of <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5CDelta%5CGamma%5Capprox%203-4" /> MeV, comparable to the inverse lifetime of the fireball created in a heavy-ion collision. The <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Ceta'" /> is of particular interested since it is intimately connected to the <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?U(1)_%7BA%7D" /> anomaly of Quantum Chromodynamics (QCD). It has been speculated that <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?U(1)_%7BA%7D" /> may become a symmetry of QCD at high temperatures and studies of the <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Ceta'" /> could indicate if that is the case. Depending on for how large temperatures the results from large <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?N_%7Bc%7D" /> can be trusted, they indicate that the <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Ceta'" /> may be possible to study experimentally in heavy-ion collisions due to its sizable in-medium width.