LesHouches

Wolfram Language package providing import rules and conversion for Supersymmetric Les Houches Accord (SLHA) files

The conversion function is fast, native to the Wolfram Language, and allows partial import of a wide variety SLHA file elements. This package is compatible with both SLHA1 (arXiv:hep-ph/0311123) and SLHA2 (arXiv:hep-ph/0801.0045) standards, as well as the proposed cross section extension (although the associated features have not been seriously tested).

Code: github.com/statius/leshouches

Installation

• Download the latest release and unpack it or clone the repository somewhere on the Wolfram Language $Path (e.g. the Applications folder in $UserBaseDirectory for Mathematica).

• Load LesHouches as

  Needs @ "LesHouches`"

  This will register the import converter in the current session.

• The import converter can be configured for automatic registration in all sessions by installing it in the $UserBaseDirectory file tree:

  InstallLesHouches @ "Converters"

  The installed files reference the absolute file path to the LesHouches package, so if the location of the package directory changes, InstallLesHouches will need to be run again.

  To remove the converter, run

  UninstallLesHouches @ "Converters"

Usage

Import elements

• General Import elements:

  element name	expression form
  "Elements"	list of all elements and options available in this file
  "Rules"	full list of rules for each element and option
  "Options"	list of rules for options, properties, and settings
  "Summary"	Summary Dataset of data element names and counts

• Data representation elements:

  element name	expression form
  "Blocks"	list of spectrum data blocks as LesHouchesDataObjects
  "Decays"	list of decay tables as LesHouchesDataObjects
  "XSections"	list of cross section tables as LesHouchesDataObjects

• Metadata elements:

  element name	expression form
  "BlockNames"	list of spectrum data blocks names
  "DecayStates"	list of decay tables initial states
  "XSectionProcesses"	list of cross section tables process rules

• Subelements of data representation elements, in the form {elem, subelem}:

  element name	subelements
  "Blocks"	"Elements", "Rules", "Names"
  "Decays"	"Elements", "Rules", "InitialStates"
  "XSections"	"Elements", "Rules", "ProcessRules"

• Specific blocks, decay tables, or cross sections in the form {elem, id}, where

  element name	identification
  "Blocks"	block name string or list of strings
  "Decays"	decay parent particle PDG number or list of numbers
  "XSections"	sequence of one or both of the initial states

• Subelements for partial data extraction of any block, decay table, or cross section table in the from {elem, id, args}, where args is a sequence of arguments that is passed to the data object(s) extracted by the specification {elem, id}.

LesHouchesDataObject

LesHouchesDataObject is a container for block, decay table, and cross section table data of the form

LesHouchesDataObject["Block" | "Decay" | "XSection", <|...|>]

where the ellipsis represents the stored data.

Each data object has static attibutes called properties. A list of the names of available properties is given by

LesHouchesDataObject[...]["Properties"]

and individual property values can be determined by passing the property name to the data object.

Each data object additionally has a set of associated functions called methods which allow extraction and transformation of the stored data. A list of the names of available methods is given by

LesHouchesDataObject[...]["Methods"]

Individual methods can be evaluated by passing their names to the data object. Some methods may take additional optional arguments that may be passed along with the method name.

Block structure

• Properties:

  property name	value form
  "Structure"	"Block"
  "Name"	block name string
  "Renormalization Scale"	number
  "Description"	block description string

• Methods:

  method name	result form
  "RawData"	all block data
  "Data"	block data in a list of associations
  "Dataset"	block data in a Dataset
  "Table"	block data in a two-dimensional array
  "Keys"	list of entry keys
  "Values"	list of entry values
  "Descriptions"	list of entry descriptions
  "Rules"	list of key -> value rules
  "Matrix"	matrix of values, if available
  "SparseArray"	SparseArray of values, indexed by key
  "HeaderPrintFormatString"	block header line Fortran format string
  "DataPrintFormatString"	block data lines Fortran format string
  "Plaintext"	plain text representation of the block

  • Method arguments:

    method name	optional argument sequence
    "Data"	function to apply to resulting list of associations
    "Dataset"	passed to resulting Dataset
    "Table"	passed to Part operating on resulting array
    "Keys"	passed to Part operating on resulting list
    "Values"	passed to Part operating on resulting list
    "Descriptions"	passed to Part operating on resulting list
    "Rules"	passed to Lookup operating on resulting list
    "Matrix"	passed to Part operating on resulting array
    "SparseArray"	passed to Part operating on resulting array

In addition, some syntactic sugar has been added to allow various shortcuts for the block structure:

1. Values can be extracted from blocks by passing a key directly to the data object .

2. Values can be changed by passing a key -> value rule (or list of rules) directly to the data object.

3. Entries or properties can be appropriately added using the builtin Append and Prepend functions.

Decay table structure

• Properties:

  property name	value form
  "Structure"	"Decay"
  "InitalState"	PDG number
  "TotalWidth"	number
  "Description"	decay table description string

• Methods:

  method name	result form
  "RawData"	all decay data
  "Data"	decay data in a list of associations
  "Dataset"	decay data in a Dataset
  "Table"	decay data in a two-dimensional array
  "FinalStates"	list of lists of final state PDG numbers
  "BranchingRatios"	list of branching ratios
  "Descriptions"	list of entry descriptions
  "Rules"	list of finalStates -> branchingRatio rules
  "HeaderPrintFormatString"	decay header line Fortran format string
  "DataPrintFormatString"	decay data lines Fortran format string
  "Plaintext"	plain text representation of the block

  • Method arguments:

    method name	optional argument sequence
    "Data"	function to apply to resulting list of associations
    "Dataset"	passed to resulting Dataset
    "Table"	passed to Part operating on resulting array
    "BranchingRatios"	passed to Part operating on resulting list
    "Descriptions"	passed to Part operating on resulting list
    "Rules"	passed to Lookup operating on resulting list

Cross section table structure

• Properties:

  property name	value form
  "Structure"	"XSection"
  "CenterOfMassEnergy"	number
  "InitialStates"	list of PDG numbers
  "FinalStates"	list of PDG numbers
  "ProcessRule"	rule between initial state list and final state list
  "Description"	cross section table description string

• Methods:

  method name	result form
  "RawData"	all cross section data
  "Data"	cross section data in a list of associations
  "Dataset"	cross section data in a Dataset
  "Table"	cross section data in a two-dimensional array
  "HeaderPrintFormatString"	cross section header line Fortran format string
  "DataPrintFormatString"	cross section data lines Fortran format string
  "Plaintext"	plain text representation of the block

  • Method arguments:

    method name	optional argument sequence
    "Data"	function to apply to resulting list of associations
    "Dataset"	passed to resulting Dataset
    "Table"	passed to Part operating on resulting array

TODO

• Build an export function
• Introduce support for the beyond-the-standard-model Les Houches event file format (arXiv:0712.3311), which essentially means allowing QNUMBER blocks and possibly adding an import/export format alias.

Project Information

Licensing

This project is released under the MIT license.

Contributions

This package is maintained by Andrew Miller (and primarily created for my own needs). Pull requests and suggestions are always welcomed.