4,313 research outputs found
Online monitoring system and data management for KamLAND
In January 22, 2002, KamLAND started the data-taking. The KamLAND detector is
a complicated system which consists of liquid scintillator, buffer oil,
spherical balloon and so on. In order to maintain the detector safety, we
constructed monitoring system which collect detector status information such as
balloon weight, liquid scintillator oil level and so on. In addition, we
constructed continuous Rn monitoring system for the Be solar neutrino
detection. The KamLAND monitoring system consists of various network, LON,
1-Wire, and TCP/IP, and these are indispensable for continuous experimental
data acquisition.Comment: Submitted to Nucl.Instrum.Meth.
N=4 Superconformal Algebra and the Entropy of HyperKahler Manifolds
We study the elliptic genera of hyperKahler manifolds using the
representation theory of N=4 superconformal algebra. We consider the
decomposition of the elliptic genera in terms of N=4 irreducible characters,
and derive the rate of increase of the multiplicities of half-BPS
representations making use of Rademacher expansion. Exponential increase of the
multiplicity suggests that we can associate the notion of an entropy to the
geometry of hyperKahler manifolds. In the case of symmetric products of K3
surfaces our entropy agrees with the black hole entropy of D5-D1 system.Comment: 25 pages, 1 figur
On the Genus Expansion in the Topological String Theory
A systematic formulation of the higher genus expansion in topological string
theory is considered. We also develop a simple way of evaluating genus zero
correlation functions. At higher genera we derive some interesting formulas for
the free energy in the and models. We present some evidence that
topological minimal models associated with Lie algebras other than the A-D-E
type do not have a consistent higher genus expansion beyond genus one. We also
present some new results on the model at higher genera.Comment: 36 pages, phyzzx, UTHEP-27
Topological Field Theories and the Period Integrals
We discuss topological Landau-Ginzburg theories coupled to the 2-dimensional
topological gravity. We point out that the basic recursion relations for
correlation functions of the 2-dimesional gravity have exactly the same form as
the Gauss-Manin differential equations for the period integrals of
superpotentials. Thus the one-point functions on the sphere of the
Landau-Ginzburg theories are given exactly by the period integrals. We discuss
various examples, A-D-E minimal models and the topological theories.Comment: 12 pages, phyzzx, UT 64
Surface Shubnikov-de Hass oscillations and non-zero Berry phases of the topological hole conduction in TlBiSe
We report the observation of two-dimensional Shubnikov-de Hass (SdH)
oscillations in the topological insulator TlBiSe. Hall
effect measurements exhibited electron-hole inversion in samples with bulk
insulating properties. The SdH oscillations accompanying the hole conduction
yielded a large surface carrier density of /cm, with the Landau-level fan diagram exhibiting the
Berry phase. These results showed the electron-hole reversibility around the
in-gap Dirac point and the hole conduction on the surface Dirac cone without
involving the bulk metallic conduction.Comment: 5 pages, 4 figure
Stress concentration in the vicinity of a hole defect under conditions of Hertzian contact
Two dimensional photoelastic stress analyses were conducted for epoxy resin models containing a hole defect under the conditions of Hertzian contact. Stress concentrations around the defect were determined as a function of several parameters. The effect of tangential traction on the stress concentration was also determined. Sharp stress concentrations occur in the vicinity of both the left and the right side of the hole. The stress concentration becomes more distinct the larger the hole diameter and the smaller distance between the hole and the contact surface. The stress concentration is greatest when the disk imposing a normal load is located at the contact surface directly over the hole. The magnitude and the location of stress concentration varies with the distance between the Hertzian contact area and the hole. The area involved in a process of rolling contact fatigue is confined to a shallow region at both sides of the hole. It was found that the effect of tangential traction is comparatively small on the stress concentration around the hole
Results from K2K and status of T2K
Results from the K2K experiment and status of the T2K experiment are
reported.Comment: 9 pages, 6 figures. Talk at International Conference on New Trends in
High-Energy Physics (Crimea2005), Yalta, Ukraine, September 10-17, 200
Comments on geometric and universal open string tachyons near fivebranes
In a recent paper (hep-th/0703157), Sen studied unstable D-branes in
NS5-branes backgrounds and argued that in the strong curvature regime the
universal open string tachyon (on D-branes of the wrong dimensionality) and the
geometric tachyon (on D-branes that are BPS in flat space but not in this
background) may become equivalent. We study in this note an example of a
non-BPS suspended D-brane vs. a BPS D-brane at equal distance between two
fivebranes. We use boundary worldsheet CFT methods to show that these two
unstable branes are identical.Comment: 8 pages, 1 figure; ver. 2 to appear in JHEP: one comment, refs and
appendices adde
Seiberg-Witten Curve for the E-String Theory
We construct the Seiberg-Witten curve for the E-string theory in
six-dimensions. The curve is expressed in terms of affine E_8 characters up to
level 6 and is determined by using the mirror-type transformation so that it
reproduces the number of holomorphic curves in the Calabi-Yau manifold and the
amplitudes of N=4 U(n) Yang-Mills theory on 1/2 K3. We also show that our curve
flows to known five- and four-dimensional Seiberg-Witten curves in suitable
limits.Comment: 18 pages, 1 figure; appendix C adde
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