122240924
Magnetic field mapping of the Belle solenoid
The mapping of the magnetic field of the Belle detector's large superconducting solenoid is described. The mapping was done with the accelerator magnets located inside the Belle solenoid excited to their nominal field values. To cope with geometrical constraints, we developed a novel moving mechanism for the field probes that uses an ultrasonic motor located in the strong magnetic field.
119516430
A high-resolution cylindrical drift chamber for the KEK B-factory
The Central Drift Chamber of the BELLE detector at the KEK B-factory is a cylindrical wire chamber device that uses a helium-based gas and aluminum field wires and is situated in a 1.5 T magnetic field. The transverse momentum resolution for charged tracks with 1.0 GeV/c transverse momentum is 0.35%. This paper describes the chamber's configuration and performance.
121845872
Test of charge-to-time conversion and multi-hit TDC technique for the BELLE CDC readout
We tested a new CDC readout scheme utilizing a Charge-to-Time conversion (QTC) technique and multi-hit TDC to record both time and charge information. The new scheme is planned to be used in the BELLE experiment at the KEK B-Factory. We built a prototype Shaper/QTC board and examined the performance with a beam test. This new scheme worked successfully. We obtained the same spatial and dEdx resolutions as those using an ordinary TDC and ADC readout scheme.
120173213
Cathode image readout in the BELLE central drift chamber
Abstract We report on the design and construction of the cathode image readout section of the BELLE detector's central drift chamber. The cathode information is used for measurements of charged particle trajectory coordinates along the beam axis and the charged-track trigger. The performance is evaluated with cosmic rays using the BELLE standard readout electronics and software. The detection efficiency in nominal conditions is found to exceed 98% and the position resolution for normal incidence is about 350 μm, which satisfies the design goals of the BELLE detector.
120866230
Z-trigger system with the BELLE Central Drift Chamber
Abstract We describe the design and performance of a fast Z -trigger system with the BELLE Central Drift Chamber. It utilizes z -position information from the axial/stereo wire hits as well as the cathode strip. This system is essential to reduce the false trigger rate from caused by the spent electrons or positrons interacting with the material around the beam pipe. We tested the performance of the system using cosmic rays in a magnetic field of 1.5 T, provided by a superconducting solenoid. The trigger efficiency was 98% for a single track passing through the interaction region. This trigger was effective in rejecting tracks originating from points more than 10 cm away from the interaction point.
17182325
Supermembrane on the PP-wave Background
Abstract We study the closed and open supermembranes on the maximally supersymmetric pp-wave background. In the framework of the membrane theory, the superalgebra is calculated by using the Dirac bracket and we obtain its central extension by surface terms. The result supports the existence of the extended objects in the membrane theory in the pp-wave limit. When the central terms are discarded, the associated algebra completely agrees with that of Berenstein–Maldacena–Nastase matrix model. We also discuss the open supermembranes on the pp-wave and elaborate the possible boundary conditions.
14169325
Universal description of viscoelasticity with foliation preserving diffeomorphisms
Abstract A universal description is proposed for generic viscoelastic systems with a single relaxation time. Foliation preserving diffeomorphisms are introduced as an underlying symmetry which naturally interpolates between the two extreme limits of elasticity and fluidity. The symmetry is found to be powerful enough to determine the dynamics in the first order of strains.
122226795
Magnetic moment of proton drip-line nucleus 9C
Abstract The magnetic moment of the proton drip-line nucleus 9 C (I π = 3 2 − , T 1 2 =126 ms ) has been measured for the first time, using the β-NMR detection technique with polarized radioactive beams. The measured value for the magnetic moment is |μ( 9 C )| = 1.3914±0.0005 μ N . The deduced spin expectation value 〈σ〉 of 1.44 is unusually larger than any other ones of even-odd nuclei.
119114995
Holographic description of the Schwinger effect in electric and magnetic field
A bstractWe consider a generalization of the holographic Schwinger effect proposed by Semenoff and Zarembo to the case with constant electric and magnetic fields. There are two ways to turn on magnetic fields, i) the probe D3-brane picture and ii) the string world-sheet picture. In the former picture, magnetic fields both perpendicular and parallel to the electric field are activated by a Lorentz transformation and a spatial rotation. In the latter one, the classical solutions of the string world-sheet corresponding to circular Wilson loops is generalized to contain two additional parameters encoding the presence of magnetic fields.
15410068
Discrete light-cone quantization in pp-wave background
We discuss the discrete light-cone quantization (DLCQ) of a scalar field theory on the maximally supersymmetric pp-wave background in ten dimensions. It has been shown that the DLCQ can be carried out in the same way as in the two-dimensional Minkowski spacetime. Then, the vacuum energy is computed by evaluating the vacuum expectation value of the light-cone Hamiltonian. The results are consistent with the effective potential obtained in our previous work [hep-th/0402028].