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Spinors Extras

Mathematica implementation of massive spinor-helicity formalism.

latest release semantic versioning license: MIT Mathematica 8.0 9.0 10.0

Overview

Implementation of massive spinor-helicity formalism in Mathematica on top of S@M package.

Spinors Extras package extends S@M capabilities by introducing symbols representing states of massive fermions: massive spinors, and vector bosons: polarization vectors along with their properties, relations between them and functions to manipulate and interchange them within the Mathematica code.

Package provides also tools for management of reference vectors that determine the quantization axes, proportionality relation among spinors and various phase conventions for spinors and polarization vectors.

Package is well suited for calculation of helicity amplitudes involving massive particles using recursive (including on-shell) methods, Feynman diagrams, or other techniques employing massive spinor helicity formalism, but some of provided tools are also useful for easier manipulations of purely massless amplitudes.

For simple usage example see tutorial on calculating e μ → e μ amplitude.

If you use results, obtained using this package, in a publication please cite: arXiv:1406.5612.

Installation

Since Spinors Extras is built on top of S@M package you need to install it first.

Automatic installation

To install Spinors Extras package automatically evaluate in Mathematica following code:

Get["https://raw.githubusercontent.com/jkuczm/SpinorsExtras/master/BootstrapInstall.m"]

Note that this will also install dependencies: EvaluationUtilities, MessagesUtilities, OptionsUtilities, PatternUtilities, ProtectionUtilities, StringUtilities, MUnitExtras and ProjectInstaller package, if you don't have it already installed.

This method will not install S@M package, you need to install it separately.

To load the package evaluate: Needs["SpinorsExtras`"].

Manual installation

  1. Download latest released SpinorsExtrasWithDependencies.zip file.

    Note that S@M package is not included in the zip file, you need to install it separately.

  2. Extract downloaded SpinorsExtrasWithDependencies.zip to any directory which is on Mathematica $Path, e.g. to one obtained by evaluating FileNameJoin[{$UserBaseDirectory,"Applications"}].

  3. To load the package evaluate: Needs["SpinorsExtras`"].

Upgrading

To upgrade SpinorsExtras package to the latest released version, evaluate code given in Automatic installation section. It will uninstall package and its dependencies and install newest versions.

Uninstall

To uninstall SpinorsExtras package and its dependencies remove SpinorsExtras, EvaluationUtilities, MessagesUtilities, OptionsUtilities, PatternUtilities, ProtectionUtilities, StringUtilities, MUnitExtras directories from installation directory.

If you used automatic installation, path to installation directory can be obtained by evaluating FileNameJoin[{$UserBaseDirectory,"Applications"}] in Mathematica.

Documentation

Spinors Extras package comes with documentation integrated with Mathematica Documentation Center. To use it, open the documentation center (Help > Documentation Center) and type "SpinorsExtras" in the search field.

Documentation for any individual symbol from Spinors Extras package, can be also called by selecting this symbols name in Mathematica and pressing the F1 key.

Online version of documentation is available on project website.

Publication introducing package is available on arXiv.

Tests

Spinors Extras package is distributed with an extensive automated test suite consisting of more than four thousand tests. To run the tests one needs MUnit package that is distributed with Mathematica version 10 and with Wolfram Workbench.

To run tests in Mathematica version 10 evaluate:

Needs["MUnit`"]

TestRun["SpinorsExtras/Tests/suite.mt"]

Compatibility

Each release of Spinors Extras package is tested with Mathematica versions 8.0, 9.0 and 10.0.

Bugs and requests

Bug reports and feature requests can be posted as GitHub issues (the preferred way) or sent directly to author’s email.

Contributing

Feel free to fork and send pull requests.

If you want to use Ant scripts from this repository you will also need to install WWBCommon project.

All contributions are welcome!

License

This package is released under The MIT License.

Versioning

Releases of this package will be numbered using Semantic Versioning guidelines.