Bochum, Univ., Diss., 2004. / Computerdatei im Fernzugriff.

Bochum, University, Diss., 2004.

Tübingen, University, Diss., 2000.

Th.--Sci. Bordeaux 1, 1978. N°: 563. / Extr. en partie de Nuclear physics. B109, 1976, 91-117 ; B117, 1976, 173-188.

Regensburg, Univ., Diss., 2009.

Thesis (Ph.D.)--Kent State University, 2008. / Title from PDF t.p. (viewed Oct. 5, 2009). Advisor: D. Mark Manley. Keywords: partial-wave analysis; multichannel; KN scattering; crystal ball. Includes bibliographical references (p. 125-127).

M.Sc. (Physics) / The differential cross-section for p(e, e¡ä¦Ø)p has been studied at Q2 ¡« 5.5 (GeV/c)2. Here Q2 represents the four momentum squared of the virtual photon in the excitation of baryonic resonances by an electron projectile. The excitation cross-section for the baryonic resonances and their de-excitation rates and channels provides information on the underlying structure of QCD. The selection of the ¦Ø decay channel constrains the particular baryonic resonances that contribute to the measured cross-section. A significant aspect of the data presented from W = 1.72 GeV to W = 1.92 GeV is that the Q2 falls in the region where the transition from non-pertubative processes characterised by constituent quarks dominate to the regime where the hard processes are expected to play an increasing important role. This is therefore an interesting region to acquire further data. In order to extract the ¦Ø-meson differential cross section from the JLAB data, the data was compared to a full Monte Carlo simulation of the detector based on events generated for omega production in a way that the production cross section was varied to achieve a match to the data. The binning selected for this procedure takes into account the measure of robustness of the stripping of the ¦Ø peak from the multi-pion background as well as the statistics in the measured data and the Monte Carlo simulation of the signal and background physics [1]. An error estimation technique for the cross section was based on determining the dependence via the Monte Carlo simulation of the extracted cross section parameters on the experimental set-up (including parameters for the spectrometer, target beam geometries and performance). We compare our results with a Regge-based model for hadronic content in the t-channel exchange of a photon in Q2 region of overlap. There is an extension of this data into a completely new region, which is the highest yet measured. The result from the study of baryonic excitation via the ¦Ø channel gives a good correlation between theory and experiment in the overlapped kinematic regime of the used theoretical simulation.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24408号 / 理博第4907号 / 新制||理||1701(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 永江 知文, 准教授 成木 恵, 教授 橋本 幸士 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

This Thesis presents measurements of the decays \Bm\to\Xi_c^0\bar{\Lambda}_c^-, \Bzb\to\Xi_c^+\bar{\Lambda}_c^- , \Bm\to\Lambda_c^+\bar{\Lambda}_c^-\Km, and \Bzb\to\Lambda_c^+\bar{\Lambda}_c^-\Kzb based on 228 million \upsbb decays collected with the \babar\ detector at the SLAC \pep2\ asymmetric-energy \B factory. The branching fraction of \Bm\to\Lambda_c^+\bar{\Lambda}_c^-\Km is measured to be $(1.22\pm0.16\pm 0.14\pm0.63)\times 10^{-3}$, and the branching fraction of $\Bz\to\Lambda_c^+\bar{\Lambda_c^-\Kzb$ is $(0.40\pm 0.33\pm 0.05 \pm 0.21)\times 10^{-3}$. The product $\BR(\Bm\to\Xi_c^0\bar{Lambda}_c^-)\times \BR(\Xi_c^0\to\Xi^-\pi^+)$ is measured to be $(2.04\pm0.59\pm0.26\pm0.53)\times 10^{-5}$, and $\BR(\Bzb\to\Xi_c^+\bar{\Lambda}_c^-)\times\BR(\Xi_c^+\to\Xi^-\pi^+\pi^+)$ is $(1.50\pm 1.07\pm 0.19 \pm 0.39)\times 10^{-5}$, where the uncertainties are statistical, systematic, and the uncertainty from the branching fraction $\BR(\Lambda_c^+\to\proton K^-\pi^+)$, respectively.

Chiral perturbation theory allows us to probe the low energy properties of hadrons. In this thesis we have looked at the axial coupling constant (see chapter 4) and baryon number violation (see chapter 5).We calculated the axial coupling constant up to O(p^4) using the extended on mass shell renormalisation scheme in chiral perturbation theory. We also included the decuplet as an explicit degree of freedom. To fit the free parameters in our expression we used a combination of lattice and experimental data. We found that the fourth order corrections were quite large, and we struggled to produce an acceptable fit to the data. We also saw that the running of g_{A}^{pn} with M_\pi predicted by lattice QCD and ChPT at O(p^4) do not agree well. This is likely due to a combination of finite size effects impacting the low pion mass lattice data and the chiral perturbative series converging slowly. For our work on baryon number violation we looked at determining the values of two low-energy constants that appear in the baryon violating chiral Lagrangian. To do this, we matched our expression to lattice data. Previous determinations of the parameters had been done without calculating the effect of loops, ours was the first investigation to see what impact the loop diagrams would have. We found that our determinations of the parameters were in agreement with previous results, suggesting the effect of the loops is small. We also performed a chiral extrapolation, and found that our results were in agreement with previous results that did not account for loop corrections. This suggests that the impact of higher-order corrections is not significant for this baryon-number-violating process.