37764222
Specification and design of a radial vane silicon tracker for a new measurement of the muon anomalous magnetic moment g-2 and electric dipole moment at J-PARC
A new measurement of the anomalous magnetic moment (g-2) and electric dipole moment (EDM) of the positive muon at J-PARC is proposed. In this experiment, we plan to use a radial vane silicon detector for detecting muon decay positrons. Specification and design study of the detector has been promoted. In order to confirm validity of use of the radial vane silicon detector and decide detector parameters, we are developing simulation and positron track reconstruction tools. First version of those using Geant4 and Hough transform method in ideal condition was constructed and the track finding efficiency was investigated. In parallel, for understanding the detector response, we began to test the most recent double sided silicon strip detector in existence. In this paper, we report the progress of the simulation and the experimental studies for the optimization of the detector parameters.
124123633
SEARCH FOR LORENTZ AND CPT VIOLATION EFFECTS IN MUON SPIN PRECESSION
121882195
Discovery of the repulsive energy shift of the kaonic hydrogen 1s state
Abstract The aim in this manuscript is to clarify the progress in understanding the nature of the K ¯ N interaction at the lowest energy, given by the recent kaonic hydrogen X-ray experiment at KEK [1]. We have observed a clear spectrum showing the kaonic hydrogen K α line, for the first time. The analysis gives the repulsive energy shift to be Δ E (1 s ) = −323 ± 63(statistical) ± 11 (systematic) eV and the energy width to be Λ(1 s ) = 407 ± 208 ± 100 eV. This result is consistent with analyses of the previous low-energy scattering data and resolves the long-standing kaonic hydrogen puzzle.
122600834
Muon catalyzed fusion experiments on muonic deuterium atom deceleration in thin solid deuterium films
Abstract Muon catalyzed fusion was investigated in a series of thin solid deuterium films by detecting protons from dd fusion. Two different contributions to the total fusion yield resulting from dμ atoms emitted from a primary hydrogen layer and from incident muons directly stopped in the deuterium film itself were observed. The thickness dependence of the fusion yield suggested the importance of molecular effects in dμ elastic scattering in D 2 .
117791711
Radioactive Muonic Atom Studies with Intense Muon Beams
New intense muon beams with flux several orders of magnitude higher than at present muon facilities would allow many novel experimental studies that were until now statistically not feasible. The investigation of the nuclear properties of short‐lived nuclei using muonic atom spectroscopy would become possible. In this paper, the recent progress of a feasibility study at RIKEN‐RAL muon facility using the cold hydrogen film method to produce radioactive muonic atoms is being reported. The first experimental results have just been obtained with stable argon ions implanted in solid deuterium films.
124815658
Measure of the spatial size for the monopole excitation in proton scattering
55054869
CONSTRUCTION AND COMMISSIONING OF EVENT TIMING SYSTEM AT SUPERKEKB
KEK linac upgrades its Event Timing System for the coming SuperKEKB project. The Event Timing System is required more complicated injection control. The damping ring is used to suppress emittance in the positron injection. The number of top-up filling rings is increased. We installed the new configuration of Event modules at Main Trigger Station for satisfying the new requirements. Besides, the upgrade of software, rearrange of optical wiring, and feasibility study are performed as the upgrade work. We conclude the new Event Timing System becomes valid. The commissioning of beamline and operation for injections with new system will be performed soon.
125753081
Magnetic Field Measurement System for the SuperKEKB Final Focus Superconducting Magnets
SuperKEKB final beam focusing system consists of different types of superconducting magnets: 8 quadrupole magnets, 4 solenoids and 43 corrector coils. In order to measure the field performances of the magnets and the coils, KEK prepared one set of harmonic coil system during the production stage in a factory, and two sets of harmonic coil systems for the cold tests at 4K for the vertical cryostat test stand in KEK. In this paper, we report these magnetic field measurement systems
115798893
Linear Collider vertex detector optimization for Higgs branching ratio measurements
The Higgs branching ratio measurement is a premier goal of the next Linear Collider physics program. Variations of a CCD vertex detector have been studied to assess the impact of inner radius and hit precision on the measurement of the Higgs branching ratios. A small dependence is found when the beampipe radius is varied between 1.2 cm and 2.4 cm, and the hit precision between 3 μm and 5 μm.
123071679
Regge trajectories of baryons in the MIT bag model
Abstract We investigate Regge trajectories of baryons in the MIT bag model. It is shown that the energy spectra shown by the trajectories can be described fairly well by the stringlike solutions of the bag model. In particular, three strings with one junction and three ends can explain the delta trajectory better than one string with two ends. The three ends occupied by each quark are assumed to be an equilateral triangle configuration in our calculations.
18761544
Study of top-quark reconstruction with LCD Fast Simulation
We report the study of top-quark reconstruction in $e^+e^- \to t\bar{t}$ events at a 500 GeV linear collider using the LCD Fast Simulator. The final states of 6 jets as well as 4 jets and lepton are used. In order to reconstruct the jets, the performance of charged and neutral cluster separation are studied. We compare top-quark reconstruction for the LCD Small and LCD Large detectors, including the effect of varying the calorimeter granularity.