Sökresultat

We investigate numerically a dynamically triangulated random surface with extrinsic curvature embedded in a three-dimensional space. Toroidal topology is used, to allow for string tension measurements by a new method. A high statistics test of the finite-size scaling of the specific heat is performed.

The integrated forest ecosystem model ForSAFE-Veg was used to simulate soil processes and understory vegetation composition at three—sugar maple, beech, yellow birch—hardwood forest sites in the Northeastern United States (one at Hubbard Brook, NH, and two at Bear Brook, ME). Input data were pooled from a variety of sources and proved coherent and consistent. While the biogeochemical component For

A highly vectorized FORTRAN program for Monte Carlo simulation of dynamical triangulated random surfaces with extrinsic curvature is presented. It is an implementation of a new procedure to measure the string tension. We summarize the method and give a detailed description of the program.

In broken-symmetry phases of models with discrete global symmetry, the physical correlation length can be measured using time-slice correlators projected to non-zero momenta. A transfer matrix based argument is used to construct the finite-size scaling for this quantity. We extract the correlation length for the two-dimensional ten-state Potts model by this means, and the surface tension from the

We present results for static hadronic correlation functions in the high temperature phase of QCD, obtained by the MTc collaboration. The measured screening lengths are compared with values for a gas of free quarks. In the ρ{variant} and N channels deviations from free quark propagation are found to be small at temperatures T ≥ 1.5Tc.

We present a detailed investigation of the heavy quark potential in the deconfined phase of pure SU(2) gauge theory at intermediate temperatures. The analysis is based on close comparison of numerical and analytical methods. The extent of the short-distance range, where because of asymptotic freedom perturbation theory gives a good description of the interaction, is determined. Slightly beyond the

We apply the spectral density reweighting technique to the analysis of the chiral phase transition in finite-temperature lattice quantum chromodynamics (QCD) with four flavors of dynamical staggered fermions and mqa=0.025. Our simulations were performed using the hybrid Monte Carlo method for LtL3 lattices with Lt=4 and L=6, 8 and 10. We calculate partition function zeros, as well as the maxima of

This study aimed to assess the potential of 64-slice MDCT in characterizing revascularized infarcted myocardium at the cellular and microvascular levels. Pigs (n=7) underwent 2 h left anterior descending coronary artery occlusion/reperfusion. In acute (2-4 h) and subacute (1 week) infarction, first-pass perfusion (FPP) (1 ml/kg of 300 mg/ml Omnipaque) was performed using a cine (rotation time 60 s

We analyze numerically the critical properties of a two-dimensional discretized random surface with extrinsic curvature embedded in a three-dimensional space. The use of the toroidal topology enables us to enforce the non-zero external extension without the necessity of defining a boundary and allows us to measure directly the string tension. We show that a most probably second- order phase transi

We have simulated the 10-state 2d Potts model with the Metropolis and Swendsen-Wang algorithms, in order to compare their performances near a first-order phase transition. We show that a simple Markov model relates the frequencies of the flips between coexisting phases and the auto-correlation times. It leads to a coherent description of the dynamics. The ratio of the algorithm efficiencies has li

In this talk I present results obtained by the MTc collaboration. We are performing an extensive numerical study of the finite temperature phase transition in lattice QCD with four flavours of staggered fermions. Here we report results for quark mass mq/T = 0.2 and preliminary data for mq/T = 0.08, obtained on 8 × 123 and 8 × 163 lattices, respectively, by using the hybrid Monte Carlo method. In a

In this talk we discuss the implementation of the full next-to-leading order QCD corrections to electroweak Higgs boson plus three jet production at the LHC within the Matchbox framework of the Herwig++ event generator. We also present numerical results for integrated cross sections and kinematic distributions.

The performance of identification algorithms (“taggers”) for hadronically decaying top quarks and W bosons in pp collisions at s = 13 TeV recorded by the ATLAS experiment at the Large Hadron Collider is presented. A set of techniques based on jet shape observables are studied to determine a set of optimal cut-based taggers for use in physics analyses. The studies are extended to assess the utility

Previous studies have shown the beneficial effects of the hepatocyte growth factor (HGF) gene on myocardial perfusion and infarction size but not on the regional strain in relationship to global left ventricular function. A noninvasive magnetic resonance (MR) study was performed to determine the effect of a new HGF gene, VM202, expressing two isoforms of HGF, on regional and global left ventricula

We present a high statistics Monte Carlo investigation of three-dimensional Z 3 symmetric models, which are related to SU(3) pure gauge theory at finite temperature. From the finite size scaling behaviour of bulk properties and the existence of metastable states, we conclude that these models exhibit a first-order phase transition. We have also performed detailed correlation length measurements i

We study the finite temperature transition in QCD with four flavours of dynamical quarks. Our simulation is performed on an 8×16 3 lattice for quarks of mass ma=0.01. At the coupling β c =5.15, we find long-lived metastable states, as well as an abrupt change in the entropy density, suggesting a first order phase transition. Using presently available results from corresponding calculations of the

The finite temperature behaviour of lattice QCD with dynamical quarks for small number of flavours Nf is investigated. Simulations have been performed on lattices of size N3σ·4 with Nσ=8 and 12 and staggered fermions of mass ma=0.1 using a hybrid algorithm. We find that the two state signal at the critical point of the pure gauge theory, which is taken as sign for a fiorst order phase transition,

Rationale and Objectives: The effects of locally delivered angiogenic factors or stem cells on the coronary artery perfusion territory are not well defined. Therefore, the aim of this study was to determine the ability of the selective injection of magnetic resonance contrast media (MR-CM) to map and quantify the territories of the major coronary arteries. Materials and Methods: Selective coronary

We present results of a numerical study of lattice QCD with four dynamical flavours of staggered fermions, performed by using a hybrid Monte Carlo algorithm on an 8×12 3 lattice. We find a rapid change in the average value of the Polyakov loop at β c =5.25±0.025 for a quark mass ma=0.025; at this mass value, the behaviour of the chiral order parameter, 〈ΨΨ〉 does not yet allow an independent deter

We study a random surface representation of Wilson loops in Z(2) gauge theory. The weights consist of an area factor, which dominates at strong coupling, and an excluded volume factor flavouring crumpled surfaces. We examine the latter one in some detail in three as well as four dimensions by use of Monte Carlo methods. In three dimensions, the critical behaviour of the surfaces is found to be det