120128880
Negative pion production in subthreshold heavy ion collisions
Abstract Inclusive π− spectra have been measured for 14N+C collisions at 41A, 67A, 80A and 135A MeV, the lowest energies measured for the charged pion. The cross sections fall exponentially with Tπ and the exponential slope factors at 90° in the nucleon-nucleon center of mass frame are determined. Energy distributions below a beam energy of 100A MeV are less steep than expected from the monotonic decrease of the slope factor down to 100A MeV. The production mechanism of energetic pions far below threshold is discussed for several models.
120128880
Negative pion production in subthreshold heavy ion collisions
Abstract Inclusive π− spectra have been measured for 14N+C collisions at 41A, 67A, 80A and 135A MeV, the lowest energies measured for the charged pion. The cross sections fall exponentially with Tπ and the exponential slope factors at 90° in the nucleon-nucleon center of mass frame are determined. Energy distributions below a beam energy of 100A MeV are less steep than expected from the monotonic decrease of the slope factor down to 100A MeV. The production mechanism of energetic pions far below threshold is discussed for several models.
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.
121629391
HOLOGRAPHY OF ROTATING DUAL GIANT WILSON LOOPS
We briefly review a tunneling picture of rotating D3-brane solutions. By applying the "double Wick rotation" to the Lorentzian solutions, we construct Euclidean solutions. The solutions are composed of dual giant gravitons and spike D3-brane solutions, and their classical actions reproduce expectation values of the k-th symmetric Wilson loops as well as correlation functions of dual giant graviton operators as expected.
14022342
Integrability and higher loops in AdS/dCFT correspondence
Abstract We further study the correspondence between open semiclassical strings and long defect operators which is discussed in our previous work [Y. Susaki, Y. Takayama, K. Yoshida, hep-th/0410139 ]. We give an interpretation of the spontaneous symmetry breaking of SO ( 6 ) → SO ( 3 ) H × SO ( 3 ) V from the viewpoint of the Riemann surface by following the argument of Minahan. Then we use the concrete form of the resolvent for a single cut solution and compute the anomalous dimension of operators dual to an open pulsating string at three-loop level. In the string side we obtain the energy of the open pulsating string solution by semiclassical analysis. Both results agree at two-loop level but we find a three-loop discrepancy.
138183455
COMPARISON BETWEEN HEXABORIDE MATERIALS FOR THERMIONIC CATHODE RF GUN
Thermionic RF guns are widely used as highly brilliant electron source for linac-driven oscillator FEL (free electron laser). They can potentially produce an electron beam with high energy, small emittance, inexpensive and compact configuration in comparison with other high brightness electron sources. The most critical issue of the thermionic RF gun is the transient cathode heating problem due to the electron backbombardment when the gun is used for an FEL driver. The heating property of cathode not only depends on the emission properties of the cathode material, but also the physical properties such as electron stopping power and range. We investigated the heating property of six hexaboride materials against the backbombarding electrons by numerical calculation of the stopping power and range. In this investigation, the emission property of the cathode was taken into account, since high electron emission is required for generation of high brightness electron beam. As a result, cerium hexaboride material has best properties for thermionic RF gun cathode material in the backbombardment effect point of view.
126190271
THE CLASSICAL EQUIVALENCE OF MONODROMY MATRICES IN SQUASHED SIGMA MODEL
We show Yangian and quantum affine symmetries are realized in two-dimensional non-linear sigma models with squashed spheres target spaces. According to these symmetries, there are two descriptions for the classical dynamics. In each description, a Lax pair and the corresponding monodromy matrix are constructed. Both Lax pairs reproduce the same equations of motion and hence they are equivalent. We show the gauge-equivalence by constructing a map between monodromy matrices with the relation of spectral parameters.
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.