G eant 4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics.

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Geant4—a simulation toolkit

Geant4 - A Simulation Toolkit

We present the first nucleon-nucleon potential at next-to-next-to-next-to-leading order (fourth order) of chiral perturbation theory. Charge dependence is included up to next-to-leading order of the isospin-violation scheme. The accuracy for the reproduction of the nucleon-nucleon $(NN)$ data below $290\text{\ensuremath{-}}\text{MeV}$ lab energy is comparable to the one of phenomenological high-precision potentials. Since $NN$ potentials of order three and less are known to be deficient in quantitative terms, the present work shows that the fourth order is necessary and sufficient for a $NN$ potential reliable up to $290\phantom{\rule{0.3em}{0ex}}\text{MeV}$. The new potential provides a promising starting point for exact few-body calculations and microscopic nuclear structure theory (including chiral many-body forces derived on the same footing).

Accurate charge dependent nucleon nucleon potential at fourth order of chiral perturbation theory

http://cds.cern.ch/record/257993/files/9401310.pdf

QCD phenomenology based on a chiral effective Lagrangian

Nowadays it has become customary in nuclear physics to denote by “tradition” the approach that considers nucleons and mesons as the relevant degrees of freedom. It is the purpose of this chapter to review this “traditional” approach in the area of nuclear forces and their applications to nuclear structure.

The Meson Theory of Nuclear Forces and Nuclear Structure

http://boson.physics.sc.edu/~myhrer/NPA707(2002)nu-deuteron.pdf

Neutrino-deuteron reactions at solar neutrino energies

CONTENTS I . INTRODUCTION ... .• ..•.•. ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 19 2. ANTINUCLEON-NUCLEON SCATTERING.. ........ .... . . . ......... . .. . ........ . . . .... ...... . . . . . . . 222 2.1 Theoretical Considerations 223 2.2 Scattering Experiments 227 2.3 Anliprotonic Atoms ..... . ...... 232 3. ANNIHILATION REACTIONS 233 3. 1 pp Annihilation at Res! 234 3.2 pp Annihilation in Flight 245 3.3 Models/or the Global A nnihilation Process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .... . . . . . . . . . . 246 3.4 Annihilation to Specific Meson States 248 4. MESON SPECTROSCOPY . . . . • . ....•..•........ . . . . . . . . . . . . ....... ....... . . . . . . . . .. . . 252 4. 1 Overview 252 4.2 Recent Results in pp Annihilation 254 5. ANTIPROTON-NUCLEUS INTERACTIONS 260 6. OUTLOOK 261

https://www.annualreviews.org/doi/pdf/10.1146/annurev.ns.41.120191.001251

Low Energy Antiproton Physics

This review gives a detailed overview of the current status of our understanding of the nucleon-nucleon forces. The authors review the known long-range meson exchange forces and explain how these forces originate from an underlying quark model constrained by chiral symmetry, a symmetry that is very well satisfied in low-energy nuclear phenomena. These effective meson exchange forces describe the large-impact-parameter nucleon-nucleon scattering. The authors show how the small-impact-parameter nucleon-nucleon scattering can be explained by the quark structure of the nucleons and why this quark model is successful in reproducing the energy dependence of the "measured" $S$- and $P$- wave nucleon-nucleon phase shifts.

Fred Myhrer

Papers

Neutrino-deuteron reactions at solar neutrino energies

Low Energy Antiproton Physics

The nucleon-nucleon force and the quark degrees of freedom

A possible resolution of the proton spin problem

Neutron beta-decay in effective field theory