Thesis BELLE2-PTHESIS-2016-007

Search for $D^{0}\to\nu\bar{\nu}$ and $B^{0}\to p\bar{\Lambda}\pi^{-}\gamma$ decay at Belle, and Belle II CDCTRG system firmware design

Yun-Tsung Lai ; Min-Zu Wang ; Paoti Chang ; Jing-Ge Shiu

2016
National Taiwan University Taipei, Taiwan

Abstract: The thesis includes three major topics. Two physics data analysis on $D^{0}$ and $B^{0}$ decays at Belle. The other is the firmware design for Belle II CDCTRG system. The first topic is a search for the $D^{0}\to\nu\bar{\nu}$ decay at Belle. We study the $D^{0}$ decay to $\nu\bar{\nu}$ and $h^{-}\ell^{+}\nu_{\ell}$ ($h=K,\pi$, and $\ell=e,\mu)$ using the data sample collected at or near the $\Upsilon(4S)$ and $\Upsilon(5S)$ with Belle detector at the KEKB asymmetric energy $e^{+}e^{-}$ collider. Absolute branching fraction measurements of these decays are done with charm flavor tagging method. Since no significant signal is found, we set an upper limit of $8.8 \times 10^{-5}$ for the branching fraction of $D^{0} \to\nu\bar{\nu}$ at the $90\%$ confidence level. We also perform the measurement of $D^{0}\to h^{-}\ell^{+}\nu_{\ell}$, and the measured branching fractions are consistent with the PDG world average. The second topic is the search for the charmless $B^0$ decay with final state particles $p \bar{\Lambda}\pi^{-} \gamma$. This decay is predicted to proceed predominantly via the $b \to s \gamma$ radiative penguin process with a high energy photon. No significant signal is found. We set an upper limit of $6.5 \times 10^{-7}$ for the branching fraction of $B^{0} \to p \bar{\Lambda} \pi^{-} \gamma$ at the $90\%$ confidence level. The third topic is NTUHEP group's work on Belle II Level-1 CDCTRG system. In this system, the trigger Merger boards simplify the data flow from readout boards to the rear-end tracking modules. The development of Merger, including hardware and firmware, will be presented in this thesis. For the data flow in the CDCTRG system, we developed an user-defined optical transmission protocol, and also the scheme of data flow control and synchronization for the whole trigger system. The design of user-defined protocol and its application will also be introduced.

Note: Presented on 13 07 2016
Note: PhD

The record appears in these collections:
Books, Theses & Reports > Theses > PhD Theses