61057513
HIGH PERFORMANCE PARALLEL COMPUTER FROM COMMODITY PC COMPONENTS
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.
118824954
Measurements of the reactions C-12 (muon-neutrino, mu-) N-12 (g.s.) and C-12 (muon-neutrino, mu-) X
16547027
Parallel Computing for QCD on a Pentium Cluster
Motivated by the computational demands of our research and budgetary constraints which are common to many research institutions, we built a ``poor man's supercomputer'', a cluster of PC nodes which together can perform parallel calculations at a fraction of the price of a commercial supercomputer. We describe the construction, cost, and performance of our cluster.
2110716
Single-bunch instability estimates for the 1-nm APS storage ring upgrade with a smaller vacuum chamber
We recently studied a lattice achieving 1 -nm emittance at the APS storage ring [1]. The successful design required very strong sextupoles in order to tune the machine to the desired positive chromaticity. A preliminary design of such magnets indicated saturation in the poles unless the vacuum chamber gets smaller by a factor of two compared to the existing APS chamber. Since the resistive wall impedance scales as 1/b3, where b is the radius of the chamber, we questioned how much current we can store in a single bunch at the 1-nm storage ring. In order to answer this question quantitatively, we calculated all wake potentials of impedance elements of the existing APS storage ring with the transverse dimension properly scaled but with the longitudinal dimension kept unchanged. With the newly calculated impedance of a smaller chamber, we estimated the single- bunch current limit. It turned out that the ring with a smaller chamber would not diminish the single-bunch current limit substantially. We present both wake potentials of 1-nm and the existing rings followed by the simulation results carried out for determining the accumulation limit to the ring.
209865899
ALICE EMCal Physics Performance Report
118409330
Unambiguous determination of the neutrino mass hierarchy using reactor neutrinos
Determination of the neutrino mass hierarchy in a reactor neutrino experiment at the medium baseline is discussed. Observation of the interference effects between the Delta m(31)(2) and Delta m(32)(2) oscillations enables a relative measurement independent of the knowledge of the absolute mass-squared difference. With a 20 kton liquid scintillator detector of the 3%/root E (MeV) energy resolution, the Daya Bay II experiment at a baseline of similar to 50 km from reactors of total thermal power 36 GW can determine the mass hierarchy at a confidence level of Delta chi(2)(MH) similar to (10 divided by 12) (3 divided by 3.5 sigma) in six years after taking into account the real spatial distribution of reactor cores. We show that the unknown residual energy nonlinearity of the liquid scintillator detector has limited impact on the sensitivity due to the self-calibration of small oscillation peaks. Furthermore, an extra increase of Delta chi(2)(MH) similar or equal to 4(9) can be obtained, by including the precise measurement of the effective mass-squared difference Delta m(mu mu)(2) of expected relative error 1.5% (1%) from ongoing long-baseline muon neutrino disappearance experiments. The sensitivities from the interference and from absolute measurements can be cross-checked. When combining these two, the mass hierarchy can be determined at a confidence level of Delta chi(2)(MH) similar to (15 divided by 20) (4 sigma) in six years.