208868910
The time-of-propagation counter for BelleII
The Belle II detector operating at the future upgrade to the KEKB accelerator will perform high-statistics precision investigations into the flavor sector of the Standard Model. As charged hadron identification is a vital element of the experiment's success, the time-of-propagation (TOP) counter has been chosen as the primary particle identification device in the barrel region of Belle II. The TOP counter is a compact variant of the detection of internally reflected Cherenkov light (DIRC) technique and relies heavily on exquisite single photon timing resolution with micro-channel plate photomultiplier tubes. We discuss the general principles of TOP operation and optimization of the Belle II TOP configuration, which is expected to provide 4 sigma or better separation of kaons and pions up to momenta of approximately 4 GeV/c.
15657977
An imaging time-of-propagation system for charged particle identification at a super B factory
Abstract Super B factories that will further probe the flavor sector of the Standard Model and physics beyond will demand excellent charged particle identification (PID), particularly K / π separation, for momenta up to 4 GeV/ c , as well as the ability to operate under beam backgrounds significantly higher than current B factory experiments. We describe an Imaging Time-of-Propagation (iTOP) detector which shows significant potential to meet these requirements. Photons emitted from charged particle interactions in a Cherenkov radiator bar are internally reflected to the end of the bar, where they are collected on a compact image plane using photodetectors with fine spatial segmentation in two dimensions. Precision measurements of photon arrival time are used to enhance the two dimensional imaging, allowing the system to provide excellent PID capabilities within a reduced detector envelope. Results of the ongoing optimization of the geometric and physical properties of such a detector are presented, as well as simulated PID performance. Validation of simulations is being performed using a prototype in a cosmic ray test stand at the University of Hawaii.
119210969
New Physics Prospects in Mixing and CP Violation at Belle II
The Belle II experiment at the SuperKEKB electron-positron collider will provide a large sample of charm mesons in addition to its primary goal of B meson production. The large data sample and wide variety of accessible D meson decay modes in a clean experimental environment provide sensitivity to new physics via D meson mixing and CP violation measurements. This contribution briefly describes selected components of the upgrade from Belle to Belle II and KEKB to SuperKEKB, and some prospects for new physics searches in the areas of charm mixing and CP violation.
117559270
Spontaneous Color Generation
Quasi fermions characterized by constant vector potentials are found to be generated in a low energy effective theory of the unified model of fermions proposed in the previous paper. In reflection of the rotational symmetry of the original theory, they are effectively represented by triplets of Dirac fields with SU(3) symmetry and can be regarded as quarks. Though the constant vector potentials emerge as a result of the spontaneous violation of Lorentz invariance, those are removable by suitable local phase transformations of effective fields, which implies that the emergent theory will be Lorentz invariant. The intrinsic mass of quasi quarks are found to be zero, though the vector potential gives a mass like term in the asymptotic form of the dispersion relation. The low energy effective theory reproduces also the generation structure of quarks. The number of generation depends on the cutoff scale, but is maximally 3