124504854
Boundary Behavior of the Superstring Vacuum Measure
5),6) In these methods, odd moduli dependence of d{J.p (55) is integrated out by using a particular choice of gravitino fields such as delta functions. 7 ) The reduced measure d{J.p(red) on the ordinary moduli space should be determined unambiguously, without the dependence of odd moduli coor­ dinates choices. It is pointed out, however, that the measure d{J.p(red) suffers from total divergence ambiguity.8),9) This ambiguity prevents us from establishing the cosmological constant to be zero. In this paper, another method for calculating the vacuum measure is studied, which is a super extension of the Belavin-Knizhnik method. 12 ) Belavin-Knizhnik stated two theorems about the bosonic string P-Ioop vacuum measure; the one is about the holomorphic factorization property, and the either is about the boundary behavior of the measure on the moduli space. The last property provides the adequate information to determine the measure uniquely. In the superstring case, there is a super extension of the Belavin-Knizhnik first theorem called "super-holomorphic factorization",lO) which states that the P-Ioop measure d{J.p (55) can be written in the following form:
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
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.
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.