18708325
Parallel Supercomputing PC Cluster and Some Physical Results in Lattice QCD
We describe the construction of a high performance parallel computer composed of PC components, present some physical results for light hadron and hybrid meson masses from lattice QCD. We also show that the smearing technique is very useful for improving the spectrum calculations.
117188835
(3+1)-Dimensional Quantum Mechanics from Monte Carlo Hamiltonian: Harmonic Oscillator*
In Lagrangian formulation, it is extremely difficult to compute the excited spectrum and wavefunctions of a quantum theory via Monte Carlo methods. Recently, we developed a Monte Carlo Hamiltonian method for investigating this hard problem and tested the algorithm in quantum-mechanical systems in 1+1 and 2+1 dimensions. In this paper we apply it to the study of the low-energy quantum physics of the (3+1)-dimensional harmonic oscillator.
118887313
$\mathscr{O}(100 GeV)$ Deci-weak $W^\prime/Z^\prime$ at Tevatron and LHC
Recently Tevatron released their measurements on invariant mass spectrum of electron/positron, as well as the di-jet arising from WW+WZ production with one W leptonically decay. Though the statistics is not significant, there are two bumps around 240 GeV and 120-160 GeV respectively. We proposed that the two bumps correspond to the extra light gauge bosons $Z^\prime$ and $W^\prime$, which couple with quarks with the deci-weak strength. In this brief report, we also simulated di-jet invariant mass distribution at the current running LHC.
2921220
Non-Gaussianity, isocurvature perturbation, gravitational waves, and a no-go theorem for the isocurvaton
We investigate the isocurvaton model, in which the isocurvature perturbation plays a role in suppressing the curvature perturbation, and large non-Gaussianity and gravitational waves can be produced with no isocurvature perturbation for dark matter. We show that in the slow-roll noninteracting multifield theory, the isocurvaton mechanism cannot be realized. This result can also be generalized to most of the studied models with generalized kinetic terms. We also study the implications for the curvaton model. We show that there is a combined constraint for curvaton on non-Gaussianity, gravitational waves, and isocurvature perturbation. The technique used in this paper can also help to simplify some calculations in the mixed inflaton and curvaton models. We also investigate the possibility of producing large negative non-Gaussianity and nonlocal non-Gaussianity in the curvaton model.
119534449
Maximum likelihood reconstruction of a detector with reflective panels
The Daya Bay reactor neutrino experiment is designed to precisely determine the neutrino mixing angle theta(13). An innovative design of the Daya Bay antineutrino detector will use optical reflective panels at the top and the bottom of the detector cylinder. This design has been tested using a prototype detector constructed at the Institute of High Energy Physics (IHEP), Beijing. A maximum likelihood event reconstruction method has been developed and tested for such a reflective prototype detector. (C) 2010 Elsevier B.V. All rights reserved.
122172140
Band spectrum for an electron on a Sierpinski gasket in a magnetic field
Abstract We consider a quantum charged particle on a fractal lattice given by a Sierpinski gasket, submitted to a uniform magnetic field, in a tight binding approximation. Its band spectrum is numerically computed and exhibits a fractal structure. The groundstate energy is also compared to the superconductor transition curve measured for a Sierpinski lattice of superconducting material.
135660011
Hybrid photodiode tube
We report the first test results on a new breed of light detector based on a photocathode followed by a silicon diode working in the bombarding mode.