Showing papers in "Computer Physics Communications in 1994"

TL;DR: Pythia and JETSET as discussed by the authors are two main components of the “Lund Monte Carlo” program suite, and they can be used to generate high-energy-physics "events".

TL;DR: Based on QCD-inspired models for multiple jets production, the authors developed a Monte Carlo program to study jet and the associated particle production in high energy pp, pA and AA collisions.

TL;DR: The program MadGraph is presented which automatically generates postscript Feynman diagrams and Fortran code to calculate arbitrary tree level helicity amplitudes by calling HELAS[1] subroutines.

TL;DR: Barberio et al. as mentioned in this paper presented an update of the photo algorithm for the Monte Carlo simulation of QED photon radiative corrections in decays, which can be used to estimate the size of the QED bremsstrahlung in the leading logarithmic (collinear) approximation.

TL;DR: In this article, the Dirac-Fock-CI method is reviewed and the MOLFDIR program suite that was developed for calculations of this type on molecular systems is described in detail.

TL;DR: The theory underlying a proposed random number generator for numerical simulations in elementary particle physics and statistical mechanics is discussed and it is shown that it can be implemented exactly on any computer complying with the IEEE-754 standard for single-precision floating-point arithmetic.

TL;DR: An F77 package for feed-forward artificial neural network data processing, JETNET 3.0, is presented, which consists of a set of subroutines focused on multilayer perceptron architectures.

TL;DR: A portable Fortran 77 implementation of a high-quality generator called RANLUX (for LUXury RANdom numbers), using the algorithm of Martin Luscher described in an accompanying article.

TL;DR: In this article, the authors describe the event generator DJANGO6, which simulates deep inelastic lepton-proton scattering including both QED and QCD radiative effects.

TL;DR: In this paper, the Kohn-Sham equations for the valence electrons were solved self-consistently using the iterative method suggested by Car and Parrinello, and the atomic geometry was determined simultaneously using a damped dynamics approach.

TL;DR: The improvement in the accuracy of a Monte Carlo integration that can be obtained by optimization of the a-priori weights of the various channels is discussed, where an effective increase in program speed by almost an order of magnitude is observed.

TL;DR: The coupled channel method for solving the bound-state Schrodinger equation is described in this paper, which is also applicable in other areas of physics, such as particle physics and computer vision.

TL;DR: The current implementation of the Davidson method for determining a few selected eigenvalues and their eigenvectors on either end of the spectrum of a large, real, symmetric matrix is presented.

TL;DR: In this paper, a new generation of force fields, termed Class II, is proposed based on the derivation and parameterization of analytic representations of quantum mechanical energy surfaces, derived from a set of representative species by systematically sampling distorted molecular structures and computing the corresponding quantum mechanics energy, energy gradient and Hessian matrices, i.e. the energy and its first and second derivatives with respect to atomic positions.

TL;DR: The CLHEP project as discussed by the authors is a C++ class library for high energy physics with the purpose of developing a general C++ language for high-energy physics applications, which can be used to describe the motivation behind the project and its current status.

TL;DR: In this paper, Monte Carlo methods are used to estimate linear combinations of lattice QCD matrix elements, using a Monte Carlo method for estimating the inverse matrix elements of a lattice matrix.

TL;DR: In this article, a molecular-dynamics (MD) algorithm based on multiresolutions in both space and time is developed for realistic modeling of materials, which is characterized by the long-range Coulomb, steric and charge-dipole interactions as well as three-body covalent potentials.

TL;DR: The first of a series to illustrate the characteristics of EMBED, a computer program for the ab-initio Hartree-Fock determination of the electronic structure of local defects in crystals, is presented in this article.

TL;DR: In this article, the electrostatic potential arising from a line lattice with an electroneutral basis is formulated as an integral over an effective potential function, and a recursive scheme for the evaluation of the derivatives of the effective potential based on the Euler-MacLaurin representation is given.

TL;DR: It is shown here that for many applications the standard methods of data fitting and approximation techniques are much better than neural networks in the sense of giving more accurate results with a lower number of adjustable parameters.

TL;DR: In this article, the authors studied the non-physical increase of kinetic energy observed in electrostatic particle simulations, defined as the relative magnitude of the kinetic energy increment in unit time to the initial energy.

TL;DR: Several variants of the Darwin model are presented; non-neutral and quasi-neutral finite-electron-mass, and quasineutral zeroelectron mass embodiments are included as mentioned in this paper.

TL;DR: Methods for simulating macromolecules by molecular dynamics on distributed memory parallel computers are described, based on the replicated data parallelisation strategy, which is both simple and effective.

TL;DR: In this article, the authors considered the interaction of a neutral atom colliding with a solid surface and developed a general quantum mechanical theory describing the multiphonon inelastic transfer processes to arbitrarily high order in number of exchanged phonons.

TL;DR: In this paper, the counting efficiency in liquid scintillation systems for electron capture nuclides coincident with gamma or isomeric transitions has been analyzed using Monte Carlo simulations.

TL;DR: In this article, a reduced matrix element (RME) package for SU(3)-coupled products of creation and annihilation operators (a†, a†a, a, aaa, aa, ana, Aa, Baa, Aaa, BAA, a †aa, anaa, AA, a *a, *aa, *a *aa), which exploits logical operations and bit manipulation procedures was introduced.

TL;DR: The application of relativistic quantum theory in atomic physics goes back to the very earliest days of quantum mechanics and has only become clear through the power of modern computers as discussed by the authors, although the application of quantum theory has only became clear through modern computers.

TL;DR: A special-purpose computer for the reconstruction of virtual images in three dimensions, HORN-1 (HOlographic ReconstructioN), which calculates light intensity at high speed and takes about 24 minutes to reconstruct a 100 × 100 × 8 virtual image.

TL;DR: In this paper, the transverse-transverse luminosity function for real and virtual photons is sampled and weighted with any user-supplied cross section σTT(γγ → X) in a hit or miss sampling.

TL;DR: In this article, a computational algorithm is constructed to solve the multiparametric problem of electromagnetic scattering by dielectric axisymmetric particles, with their relative position and interaction taken into account.