| Title▼ | Belle II Number▼ | Tags | Submit date▼ | Downloads |
|---|---|---|---|---|
|
The Belle II experiment Status and ProspectsPublic
The Belle II experiment at the SuperKEKB energy-asymmetric $e^{+}e^{-}$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times10^{35}\: cm^{-2}s^{-1}$ and the Belle II experiment aims to record $50\:ab^{-1}$ of data, a factor of 50 more than its predecessor. With… |
BELLE2-CONF-PROC-2019-019 | - | 2019-12-24 |
|
| Flavour measurements in the next five years (Focusing on Belle II)Public | BELLE2-TALK-CONF-2020-005 | - | 2019-12-05 |
|
|
Beam-constrained vertexing for B physics at the Belle II ExperimentPublic
The Belle II experiment, which recently began collecting $e^+e^-$ collision data, will extend the successful physics program of BaBar and Belle with a 30-fold increase in integrated luminosity and an improved detector. In particular, the vertex position resolution of Belle II is better than that of its predecessors by about a factor of two. The hi… |
BELLE2-CONF-PROC-2019-017 | - | 2019-11-24 |
|
|
Missing mass searches at B-Factories: Belle II first results and prospectsPublic
Review of missing mass searches at B-Factories, comparing BaBar results to Belle II first results and prospects |
BELLE2-TALK-CONF-2020-004 | - | 2019-11-21 |
|
|
Belle II 実験ARICH 検出器の光反射ミラー部における粒子識別性能の評価Public
茨城県つくば市にある高エネルギー加速器研究機構ではBelle II 実験が今年4 月から行われている。Belle II 実験はSuperKEKB 加速器を用いて電子・陽電子を加速し衝突させ、大量のB 中間子を生成するルミノシティーフロンティア実験である。B 中間子の崩壊過程を精密に測定することにより標準模型からのズレを観測し、新物理の探索を目的としている。前身のBelle 実験ではB 中間子の稀崩壊を測定するにはデータ量が不足していたので、本実験ではルミノシティを約50 倍に増やし統計量・精度を向上させる。Belle II 検出器は各役割に応じた複数の検出器からなる複合型測定器であり、その中でもEndcap 部にあるARICH(Ring Imaging CHerenkov) 検出器は荷電K… |
BELLE2-MTHESIS-2021-030 | - | 2019-11-11 |
|
|
Calibration of aerogel ring-imaging Cherenkov detector in Belle II spectrometerPublic
The Aerogel Ring-Imaging Cherenkov (ARICH) detector provides a charged particle identification in the endcap region of the Belle II spectrometer at the SuperKEKB asymmetric-energy e + e − collider in Tsukuba, Japan. The ARICH consists of a double layer aerogel radiator in a focusing configuration, an expansion volume and a plane of hybrid avalanch… |
BELLE2-PTHESIS-2021-014 | - | 2019-11-11 |
|
|
Penguin-Hunting with Neural Nets Time-Dependent CP Violation Measurement of B^0 \to K_s \pi^0Public
As it stands, the CP violating parameters of B^0 \to K_s \pi^0 show tension between the Standard Model and experimental results at the 2\sigma level, making it a prime candidate to investigate New Physics particles such leptoquarks and Z0. This discrepancy can be resolved at the Belle II experiment as we expected to achieve a forty-fold increase o… |
BELLE2-MTHESIS-2023-011 | - | 2019-11-11 |
|
|
Radiation dose measurement in Belle II electromagnetic calorimeter during Super KEKB accelerator phase-2 operation (In Japanese) （日本語原題）SuperKEKB加速器第二期試験運転におけるBelle II実験電磁カロリメータでの放射線量測定Public
Belle II実験の電磁カロリメーターが使用しているPINフォトダイオードの電流値を測定するシステムを構築・運用し、SuperKEKB加速器第二期運転期間中の放射線量は0.4Gyであったことがわかった。また、LYSOカウンターを高速サンプリング読み出しすると数十μsの時間スケールで放射線量の増減を測定できることを示した。 |
BELLE2-MTHESIS-2021-008 | - | 2019-11-11 |
|
|
Etude du bruit de fond induit par les nano-faisceaux du collisionneur SuperKEKB et préparation de l’analyse de physique de l’expérience Belle IIPublic
The Belle II experiment aims to discover new physics processes not described by the standard model of particle physics, based on measurements of unprecedented precision with B and D mesons, and τ leptons. The experiment started recording SuperKEKB collisions in 2018. This e+e- collider targets the highest ever achieved instantaneous luminosity, ba… |
BELLE2-PTHESIS-2021-010 | - | 2019-11-11 |
|
|
Belle II実験Phase IIランにおけるARICH検出器のアライメントおよびB -> Kpi崩壊の探索Public
Belle II 実験は、茨城県つくば市にある高エネルギー加速器研究機構(KEK) で稼働し始めた SuperKEKB 加速器を用いて7GeV に加速した電子と4GeV に加速した陽電子の衝突によりB 中間 子対を大量に生成し、崩壊過程をBelle II 検出器を用いて詳細に調べるルミノシティフロンティア実 験である。B 中間子の崩壊過程に含まれるごく稀な事象を精密に調べることで、標準模型を超える新 しい物理を探索することを目的としている。 先行研究であるBelle 実験ではB 中間子と反B 中間子のCP 対称性の破れを発見し、2008 年の 小林・益川両氏のノーベル物理学賞受賞に貢献した。2010 年6 月にSuperKEKB 加速器への加速器 のアップグレードとBelle II 実験に… |
BELLE2-MTHESIS-2021-031 | - | 2019-11-11 |
|
|
Systematic Studies on Track Reconstruction Efficiency at Belle IIPublic
This thesis provides a detailed overview on the electron and positron tracking efficiency of the Belle II detector. It is possible to calculate this efficiency by using kinematic properties of Bhabha scattering and fundamental properties of the electromagnetic calorimeter. The central result is the comparison of tracking efficiencies between MC s… |
BELLE2-MTHESIS-2022-012 | - | 2019-11-11 |
|
|
Studies to upgrade the silicon tracker of the Belle II experimentPublic
Various upgrade options for the vertex detector of the Belle II experiment are studied in this report. First, using a tool based on simplified calculations of tracking performances, we observe a factor two improvement with respect to the current Belle II tracker on track parameter resolutions, by reducing the radius and thickness of the beampipe a… |
BELLE2-MTHESIS-2021-022 | - | 2019-11-11 |
|
|
Reconstruction Methods for Semi-leptonic Decays of B-mesons with the Belle II ExperimentPublic
The Belle II detector located in Tsukuba, Japan, building on the work of its predecessor Belle, is scheduled for long-term data collection from electron-positron $e^{+} e^{-}$ collisions commencing in early 2019, for the purpose of studying rare B-meson decays in the search for new physics beyond the Standard Model. The Belle II Analysis Softwa… |
BELLE2-MTHESIS-2019-002 | - | 2019-11-11 |
|
|
Search for Highly Ionizing Particles with the Pixel Detector in the Belle II ExperimentPublic
The Belle II experiment located at the high-energy research facility KEK in Tsukuba (Ibaraki) Japan started operation in 2018. Compared to the predecessor experiment Belle, Belle II plans to increase the peak luminosity by a factor of 40, by employing nanobeam technology in the interaction region. A novel Pixel Detector (PXD) featuring two layers … |
BELLE2-MTHESIS-2019-003 | - | 2019-11-11 |
|
|
The Study and Shielding of Electromagnetic Radiation from SuperKEKB Electron and Positron Beam InteractionsPublic
This project contributes to the research and development studies towards successful commissioning of the SuperKEKB electron-positron collider. This accelerator and storage rings complex aims at delivering the high-luminosity collisions of beams of electrons and positrons needed for the Belle II experiment. Such beams produce parasitic radiation --… |
BELLE2-PTHESIS-2019-001 | - | 2019-11-11 |
|
|
First application of CsI(Tl) pulse shape discrimination at an $e^+ e^-$ collider to improve particle identification at the Belle II experimentPublic
This dissertation investigates CsI(Tl) pulse shape discrimination (PSD) as a novel experimental technique to improve challenging areas of particle identification at high energy $e^+ e^-$ colliders using CsI(Tl) calorimeters. In this work CsI(Tl) PSD is implemented and studied at the Belle II experiment operating at the SuperKEKB $e^+ e^-$ collider… |
BELLE2-PTHESIS-2021-018 | - | 2019-11-11 |
|
|
Exclusive untagged analysis of the semi-leptonic decay B→ρlν in preparation for extracting |V_ub| using early Belle II dataPublic
In this thesis, the decay B → ρlν was studied using Belle II Monte Carlo simulation corresponding to the early Belle II data size of 6.5 fb−1. Selections were performed to reduce background events, and BDTs were trained to further reject continuum and BB background events. It was found that performing a FOM selection on the BDT output classifiers … |
BELLE2-MTHESIS-2019-004 | - | 2019-11-11 |
|
|
Multiparameter Analysis of the Belle II Pixeldetector’s Data Using Principal Components Analysis and Neural NetworksPublic
In a recent thesis, the use of self-organising maps (SOM) and feed forward networks for classification processes was applied in the analysis of data from Belle II’s pixel vertex detector. This thesis continues the work by examining correlations between the charge-related and size-related pixel cluster properties. To find correlations, principal co… |
BELLE2-UTHESIS-2019-001 | - | 2019-11-11 |
|
|
Comparison of the Simulated Lifetime of Primary and Secondary Lambda_0 Particles in Belle II Analysis Software FrameworkPublic
The problem of the simulated lifetime of secondary Lambda_0 particles in the Belle II detector simulation has been reported by Hikari Hirata at Nagoya University. As stated in her report, the difference between the simulated lifetime of secondary Lambda_0 particles and the one of primary Lambda_0 particles is about 10 percent. In the Belle II expe… |
BELLE2-UTHESIS-2019-002 | - | 2019-11-11 |
|
|
Performance tuning of photon sensor and readout electronics and evaluation of photon detection efficiency for Belle II TOP counter (in Japanese)Public
Belle II 実験ではe+e 衝突から生じるB 中間子対を500 億事象という世界最高統計量で収集し、その 希崩壊過程を精密に測定することで標準模型を超える新事象の探索を行う。重いB 中間子崩壊の終状態に 多く含まれる比較的軽いK/ 中間子の識別を高い効率で行う必要があるため、我々は新型粒子識別装置 Time-Of-Propagation (TOP) カウンターを導入し、識別効率95% 以上、誤識別率5% 以下での識別を目指す。 TOP カウンターは石英輻射体とその端面に取り付けた光検出器Micro-Channel-Plate (MCP) -PMT で構 成されている。石英輻射体K= が通過する際に異なる放出角で発生するチェレンコフ光子を光検出器で20 個 程度検出し、その検出時間・… |
BELLE2-MTHESIS-2019-008 | - | 2019-11-11 |
|