56000332
PROGRESS OF DESIGN STUDY OF INTERACTION REGION QUADRUPOLES FOR THE SUPER-KEKB
For KEKB upgrade, we are studying the design of the final focus quadrupoles to achieve very small β-functions at the interaction point (IP). For each beam, the final beam focusing system consists of quadrupole-doublet of the superconducting and permanent magnets. In this paper, the design progress of final focusing magnets is reported.
116975784
Higgs branching ratio measurements at a future Linear Collider
The next Linear Collider should provide the capability to measure with precision the Higgs branching ratios, constraining the models of electroweak symmetry breaking. The precision of a proposed CCD vertex detector is studied for 120 GeV/c2 and 140 GeV/c2 Higgs production at s=500 GeV.
185755181
The SuperKEKB accelerator status
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.
16601897
Mechanisms affecting performance of the BaBar resistive plate chambers and searches for remediation
The BaBar experiment at PEPII relies on the instrumentation of the flux return (IFR) for both muon identification and KL detection. The active detector is composed of resistive plate chambers (RPCs) operated in streamer mode. Since the start of operation the RPCs have suffered persistent efficiency deterioration and dark current increase problems. The ‘‘autopsy’’ of bad BaBar RPCs revealed that in many cases uncured linseed oil droplets had formed on the inner surface of the Bakelite plates, leading to current paths from oil ‘‘stalagmites’’ bridging the 2mm gap. In this paper, a possible model of this ‘‘stalagmite’’ formation and its effect on the dark current and efficiency of RPC chambers is presented. Laboratory test results strongly support this model. ARTICLE IN PRESS *Corresponding author. Tel.: +1-609-258-4391; fax: +1-609-258-6360. E-mail address: changguo@princeton.edu (C. Lu). 0168-9002/03/$ see front matter r 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0168-9002(03)01292-0 Based upon this model we are searching for solutions to eliminate the unfavorable effect of the oil stalagmites. The lab tests show that the stalagmite resistivity increases dramatically if exposed to the air, an observation that points to a possible way to remedy the damage and increase the efficiency. We have seen that flowing an oxygen gas mixture into the chamber helps to polymerize the uncured linseed oil. Consequently, the resistivity of the bridged oil stalagmites increases, as does that of the oil coating on the frame edges and spacers, significantly reducing the RPC dark currents and low-efficiency regions. We have tested this idea on two chambers removed from BaBar because of their low efficiency and high dark current. These test results are reported in the paper, and two other remediation methods also mentioned. We continue to study this problem, and try to find new treatments with permanent improvement. r 2003 Elsevier Science B.V. All rights reserved.
54880563
Design and Status of the SuperKEKB Accelerator Control Network System
We have upgraded the accelerator control network system for SuperKEKB, the next generation B-factory experiment in Japan. The designed network system has the higher performance based on the wider bandwidth data transfer, and more reliable and redundant configuration. For the SuperKEKB beamline construction and accelerator components maintenance, we have installed the new wireless network system consists with the Leaky Coaxial (LCX) cable antennas and collinear antennas into the 3 km circumference accelerator tunnel. In this paper, we describe the design and current status of the SuperKEKB accelerator control network system.
123947708
A Search for Deeply-bound Kaonic Nuclear States by In-flight $^3$He($K^-, n$) Reaction at J-PARC
F. Sakuma, S. Ajimura, G. Beer, H. Bhang, M. Bragadireanu P. Buehler, L. Busso, M. Cargnelli, S. Choi, C. Curceanu S. Enomoto, D. Faso, H. Fujioka, Y. Fujiwara, T. Fukuda C. Guaraldo, T. Hashimoto, R.S. Hayano, T. Hiraiwa, M. Iio M. Iliescu, K. Inoue, Y. Ishiguro, T. Ishikawa, S. Ishimoto T. Ishiwatari, K. Itahashi, M. Iwai, M. Iwasaki, Y. Kato S. Kawasaki, P. Kienle, H. Kou, Y. Ma, J. Marton, Y. Matsuda Y. Mizoi, O. Morra , T. Nagae, H. Noumi, H. Ohnishi, S. Okada H. Outa, K. Piscicchia, M. Poli Lener, A. Romero Vidal Y. Sada, A. Sakaguchi, M. Sato, A. Scordo, M. Sekimoto, H. Shi D. Sirghi, F. Sirghi, K. Suzuki, S. Suzuki, T. Suzuki K. Tanida, H. Tatsuno, M. Tokuda, D. Tomono, A. Toyoda K. Tsukada, O. Vazquez Doce, E. Widmann, B.K. Wuenschek T. Yamaga, T. Yamazaki, H. Yim, Q. Zhang, J. Zmeskal
22969599
Conceptual 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 determine 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. We are improving these tools close to real condition and the multi-track finding efficiency has been investigated. In this paper, we report the progress of the studies in simulation and track finding tools for the optimization of the detector parameters.
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.
120844992
J-PARC Muon Science Facility with use of 3 GeV Proton Beam
The J-PARC muon science experimental area is planned to be located in the integrated building of the facility for materials and life science study. One muon target will be installed upstream of the neutron target in Phase 1. Under the limited budget of phase 1, it is not possible to install all the secondary beam lines, therefore, any group who is interested in either from the EDM experimental group, or the muon cooling experimental group, or the μ SR group is welcome to join us with constructing its dedicated secondary muon beam line.
118407007
Recent Development of a point positive muon source at the RIKEN‐RAL muon facility
We report recent progress of slow muon beam line constructed at the RIKEN‐RAL muon facility. The slow muons are muons which are re‐accelerated from the one at thermal velocity. This beam is expected to have very small emittance compared with conventional muon beam, where muons are obtained from decays of pions at rest or on move. Especially, its smallness of energy spread will make it possible to apply μSR technique to the studies of thin films, multilayered systems, nanomaterials, and other objects of restricted dimensionality. Intense slow muon beams which can be realized at future neutrino factories will be a valuable tool for material science.