UrQMD

Last updated
UrQMD Hadron-String Transport Model
Original author(s) Steffen Bass, Marcus Bleicher, Horst Stöcker et al.
Developer(s) Goethe University
Stable release
UrQMD 3.4 / August 2014
Operating system UNIX
Type Monte Carlo method, Particle physics
License UrQMD user license
Website

UrQMD (Ultra relativistic Quantum Molecular Dynamics) is a fully integrated Monte Carlo simulation package for Proton+Proton, Proton+nucleus and nucleus+nucleus interactions. UrQMD has many applications in particle physics, high energy experimental physics and engineering, shielding, detector design, cosmic ray studies, and medical physics.

Monte Carlo methods, or Monte Carlo experiments, are a broad class of computational algorithms that rely on repeated random sampling to obtain numerical results. The underlying concept is to use randomness to solve problems that might be deterministic in principle. They are often used in physical and mathematical problems and are most useful when it is difficult or impossible to use other approaches. Monte Carlo methods are mainly used in three problem classes: optimization, numerical integration, and generating draws from a probability distribution.

Particle physics Branch of physics

Particle physics is a branch of physics that studies the nature of the particles that constitute matter and radiation. Although the word particle can refer to various types of very small objects, particle physics usually investigates the irreducibly smallest detectable particles and the fundamental interactions necessary to explain their behaviour. By our current understanding, these elementary particles are excitations of the quantum fields that also govern their interactions. The currently dominant theory explaining these fundamental particles and fields, along with their dynamics, is called the Standard Model. Thus, modern particle physics generally investigates the Standard Model and its various possible extensions, e.g. to the newest "known" particle, the Higgs boson, or even to the oldest known force field, gravity.

Experimental physics is the category of disciplines and sub-disciplines in the field of physics that are concerned with the observation of physical phenomena and experiments. Methods vary from discipline to discipline, from simple experiments and observations, such as the Cavendish experiment, to more complicated ones, such as the Large Hadron Collider.

Since version 3.3, an option has been incorporated to substitute part of the collision with a hydrodynamic model.

UrQMD is available in as open-source Fortran code.[ citation needed ]

Open-source software software licensed to ensure source code usage rights

Open-source software (OSS) is a type of computer software in which source code is released under a license in which the copyright holder grants users the rights to study, change, and distribute the software to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. Open-source software is a prominent example of open collaboration.

Fortran General-purpose programming language

Fortran is a general-purpose, compiled imperative programming language that is especially suited to numeric computation and scientific computing.

UrQMD is developed using the FORTRAN language. Under Linux the gfortran compiler is necessary to build and run the program.

Linux Family of free and open-source software operating systems based on the Linux kernel

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution.

The GNU Compiler Collection (GCC) is a compiler system produced by the GNU Project supporting various programming languages. GCC is a key component of the GNU toolchain and the standard compiler for most projects related to GNU and Linux, the most notable is the Linux kernel. The Free Software Foundation (FSF) distributes GCC under the GNU General Public License. GCC has played an important role in the growth of free software, as both a tool and an example.

The UrQMD model is part of the GEANT4 simulation package and can be used as a low-energy hadronic interaction model within the air shower simulation code CORSIKA.

CORSIKA is a physics computer software for simulation of extensive air showers induced by high energy cosmic rays. It may be used up to and beyond the highest energies of 100 EeV.

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Atom smallest unit of a chemical element

An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small; typical sizes are around 100 picometers.

Nuclear physics field of physics that deals with the structure and behavior of atomic nuclei

Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions. Other forms of nuclear matter are also studied. Nuclear physics should not be confused with atomic physics, which studies the atom as a whole, including its electrons.

Nucleon particle that makes up the atomic nucleus (proton or neutron)

In chemistry and physics, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus. The number of nucleons in a nucleus defines an isotope's mass number.

Proton nucleon (constituent of the nucleus of the atom) that has positive electric charge; symbol p

A proton is a subatomic particle, symbol
p
or
p+
, with a positive electric charge of +1e elementary charge and a mass slightly less than that of a neutron. Protons and neutrons, each with masses of approximately one atomic mass unit, are collectively referred to as "nucleons".

Strong interaction force between hadrons that remains constant at any distance as the hadrons travel within a nucleus

In particle physics, the strong interaction is the mechanism responsible for the strong nuclear force (also called the strong force, nuclear strong force, or colour force), and is one of the four known fundamental interactions, with the others being electromagnetism, the weak interaction, and gravitation. At the range of 10−15 m (1 femtometer), the strong force is approximately 137 times as strong as electromagnetism, a million times as strong as the weak interaction, and 1038 times as strong as gravitation. The strong nuclear force holds most ordinary matter together because it confines quarks into hadron particles such as the proton and neutron. In addition, the strong force binds neutrons and protons to create atomic nuclei. Most of the mass of a common proton or neutron is the result of the strong force field energy; the individual quarks provide only about 1% of the mass of a proton.

Nuclear shell model model of the atomic nucleus

In nuclear physics and nuclear chemistry, the nuclear shell model is a model of the atomic nucleus which uses the Pauli exclusion principle to describe the structure of the nucleus in terms of energy levels. The first shell model was proposed by Dmitry Ivanenko in 1932. The model was developed in 1949 following independent work by several physicists, most notably Eugene Paul Wigner, Maria Goeppert Mayer and J. Hans D. Jensen, who shared the 1963 Nobel Prize in Physics for their contributions.

Subatomic particle Particle whose size or mass is less than that of the atom, or of which the atom is composed; small quantum particle

In the physical sciences, subatomic particles are particles much smaller than atoms. The two types of subatomic particles are: elementary particles, which according to current theories are not made of other particles; and composite particles. Particle physics and nuclear physics study these particles and how they interact. The idea of a particle underwent serious rethinking when experiments showed that light could behave like a stream of particles as well as exhibiting wave-like properties. This led to the new concept of wave–particle duality to reflect that quantum-scale "particles" behave like both particles and waves. Another new concept, the uncertainty principle, states that some of their properties taken together, such as their simultaneous position and momentum, cannot be measured exactly. In more recent times, wave–particle duality has been shown to apply not only to photons but to increasingly massive particles as well.

Air shower (physics) shower of particles from a high energy cosmic ray hitting Earths atmosphere

An air shower is an extensive cascade of ionized particles and electromagnetic radiation produced in the atmosphere when a primary cosmic ray enters the atmosphere. When a particle, which could be a proton, a nucleus, an electron, a photon, or (rarely) a positron, strikes an atom's nucleus in the air it produces many energetic hadrons. The unstable hadrons decay in the air speedily into other particles and electromagnetic radiation, which are part of the shower components. The secondary radiation rains down, including x-rays, muons, protons, antiprotons, alpha particles, pions, electrons, positrons, and neutrons.

GEANT is the name of a series of simulation software designed to describe the passage of elementary particles through matter, using Monte Carlo methods. The name is an acronym formed from "GEometry ANd Tracking". Originally developed at CERN for high energy physics experiments, GEANT-3 has been used in many other fields.

Nuclear force A force that acts between the protons and neutrons of atoms

The nuclear force is a force that acts between the protons and neutrons of atoms. Neutrons and protons, both nucleons, are affected by the nuclear force almost identically. Since protons have charge +1 e, they experience an electric force that tends to push them apart, but at short range the attractive nuclear force is strong enough to overcome the electromagnetic force. The nuclear force binds nucleons into atomic nuclei.

CASTEP is a shared-source academic and commercial software package which uses density functional theory with a plane wave basis set to calculate the electronic properties of crystalline solids, surfaces, molecules, liquids and amorphous materials from first principles. CASTEP permits geometry optimisation and finite temperature molecular dynamics with implicit symmetry and geometry constraints, as well as calculation of a wide variety of derived properties of the electronic configuration. Although CASTEP was originally a serial, Fortran 77-based program, it was completely redesigned and rewritten from 1999-2001 using Fortran 95 and MPI for use on parallel computers by researchers at the Universities of York, Durham, St. Andrews, Cambridge and Rutherford Labs. It has since been updated to Fortran 2003.

Computational engineering

Not to be confused with computer engineering.

Nuclear structure

Understanding the structure of the atomic nucleus is one of the central challenges in nuclear physics.

FLUKA is a fully integrated Monte Carlo simulation package for the interaction and transport of particles and nuclei in matter. FLUKA has many applications in particle physics, high energy experimental physics and engineering, shielding, detector and telescope design, cosmic ray studies , dosimetry , medical physics, radiobiology. A recent line of development concerns hadron therapy.

The automatic calculation of particle interaction or decay is part of the computational particle physics branch. It refers to computing tools that help calculating the complex particle interactions as studied in high-energy physics, astroparticle physics and cosmology. The goal of the automation is to handle the full sequence of calculations in an automatic (programmed) way: from the Lagrangian expression describing the physics model up to the cross-sections values and to the event generator software.

Atomic nucleus core of the atom; composed of bound nucleons (protons and neutrons)

The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment. After the discovery of the neutron in 1932, models for a nucleus composed of protons and neutrons were quickly developed by Dmitri Ivanenko and Werner Heisenberg. An atom is composed of a positively-charged nucleus, with a cloud of negatively-charged electrons surrounding it, bound together by electrostatic force. Almost all of the mass of an atom is located in the nucleus, with a very small contribution from the electron cloud. Protons and neutrons are bound together to form a nucleus by the nuclear force.

NA61 experiment

NA61/SHINE is a particle physics experiment at the Super Proton Synchrotron (SPS) at the European Organization for Nuclear Research (CERN). The experiment studies the hadronic final states produced in interactions of various beam particles with a variety of fixed nuclear targets at the SPS energies.

Quantum ESPRESSO is a suite for ab initio quantum chemistry methods of electronic-structure calculation and materials modeling, distributed for free under the GNU General Public License. It is based on Density Functional Theory, plane wave basis sets, and pseudopotentials. ESPRESSO is an acronym for opEn-Source Package for Research in Electronic Structure, Simulation, and Optimization.

A charged particle accelerator is a complex machine that takes elementary charged particles and accelerates them to very high energies. Accelerator physics is a field of physics encompassing all the aspects required to design and operate the equipment and to understand the resulting dynamics of the charged particles. There are software packages associated with each such domain. There are a large number of such codes. The 1990 edition of the Los Alamos Accelerator Code Group's compendium provides summaries of more than 200 codes. Certain of those codes are still in use today although many are obsolete. Another index of existing and historical accelerator simulation codes is located at