京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21564号 / 理博第4471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)准教授 市川 温子, 教授 鶴 剛, 教授 中家 剛 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

In the thesis we study the decay of B0 meson to D∗ s and ρ mesons. The thesis explains the methods and approaches to data analysis in so-called B-factories, simmilar to the KEKB accelerator. The aim of this thesis is to calculate the branching fraction of this decay to further improve the previously measured branching ratio at BaBar experiment with additional data gained from an ex- periment with higher integrated luminosity. This thesis's prospect is not only broadening our knowledge of branching fractions of B0 meson decays, but also it is a starting point for further analysis with the goal of broadening our knowl- edge of CP symmetry violation in the Standard Model by measuring angles of the Unitary Triangle. 1

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20171号 / 理博第4256号 / 新制||理||1612(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, 教授 中家 剛, 教授 大西 明 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

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.