8106301
ZZ brane amplitudes from matrix models
We study instanton contribution to the partition function of the one matrix model in the k-th multicritical region, which corresponds to the (2,2k−1) minimal model coupled to Liouville theory. The instantons in the one matrix model are given by local extrema of the effective potential for a matrix eigenvalue and identified with the ZZ branes in Liouville theory. We show that the 2-instanton contribution in the partition function is universal as well as the 1-instanton contribution and that the connected part of the 2-instanton contribution reproduces the annulus amplitudes between the ZZ branes in Liouville theory. Our result serves as another nontrivial check on the correspondence between the instantons in the one matrix model and the ZZ branes in Liouville theory, and also suggests that the expansion of the partition function in terms of the instanton numbers are universal and gives systematically ZZ brane amplitudes in Liouville theory.
122497415
R&D on Proton Extinction Monitor for COMET Project
The COMET experiment searches for a muon to electron conversion process that is one of the lepton flavor violation processes. We use an 8‐GeV pulsed proton beam. The proton extinction ratio is an important parameter. In order to measure this ratio pulse‐by‐pulse, we are developing a monitoring device. This device is called Proton Extinction Monitor and is a gas Cerenkov detector with gating photomultiplier tubes(PMT). The result of the investigation is that ethane is a promising gas for the Cerenkov radiator gas. A gating PMT is under development. We fabricated a divider circuit which switches at 10‐kHz and has a cutoff ratio of 10−6.
162176254
Development on Electromagnetic Calorimeter for COMET / PRISM
120314212
Measurement of radiation heating induced by secondary particles from 12-GeV primary proton¿beam interactions
Abstract We measured radiation heating induced by secondary particles from 12-GeV primary proton–beam interactions. A newly developed “cryogenic calorimeter” technique was employed to precisely measure heat fluxes of 0.2–1 W deposited in a large copper absorber. The results were compared with calculations by using Monte-Carlo codes, MARS and PHITS.
15727631
STUDIES FOR THE PRISM FFAG RING FOR THE NEXT GENERATION MUON TO ELECTRON CONVERSION EXPERIMENT
High intensity and high quality muon beams are needed for next generation lepton flavour violation experiments. Such beams can be produced by sending a short proton pulse to a pion production target, capturing the pions and performing RF phase rotation on the resulting muon beam in an FFAG ring. Such a solution was proposed for the PRISM project and this paper summarizes its current status. In particular the PRISM task force was created to address the accelerator and detector issues that need to be solved in order to realise the PRISM experiment. Alternative designs for the PRISM FFAG ring are discussed and their performance compared. The injection/extraction systems and matching to the solenoid channels upstream and downstream of the FFAG ring are presented. The future direction for the study will be outlined.
54175451
MUSIC, THE WORLD'S HIGHEST INTENSE DC MUON BEAM USING A PION CAPTURE SYSTEM
MuSIC is a project to provide the world’s highestintensity muon beam with continuous time structure at Research Center of Nuclear Physics (RCNP) of Osaka University, Japan. A pion capture system using a superconducting solenoid magnet and a part of superconducting muon transport solenoid channel have been build in 2009. The highest muon production efficiency was demonstrated by the beam tests. Results of the beam test conclude that the MuSIC can provide more than 10 8 muons/sec using a 400 W proton beam.
126008905
An Asymmetric collider with the TRISTAN Main Ring