<html> <head> <title>Glossary</title> <link rel="stylesheet" type="text/css" href="pythia.css"/> <link rel="shortcut icon" href="pythia32.gif"/> </head> <body> <h2>Glossary</h2> <dl> <dt>BR</dt> <dd>Beam Remnants; not much used since it may be confused with Branching Ratio</dd> <dt>BSM</dt> <dd>Beyond-the-Standard-Model physics, as a generic term for anything not contained within the SM</dd> <dt>FSR</dt> <dd>Final-State Radiation, implemented in terms of timelike showers</dd> <dt>LHA</dt> <dd>Les Houches Accord for user processes, describing which process-level information should be stored to allow further showering and hadronization of "skeleton" hard processes</dd> <dt>LHAPDF</dt> <dd>Les Houches Accord Parton Distribution Functions, originally a standard format for defining PDF's and later a library with such PDF's</dd> <dt>LHEF</dt> <dd>Les Houches Event File(s), a file format for storing LHA process and event information</dd> <dt>ISR</dt> <dd>Initial-State Radiation, implemented in terms of spacelike showers</dd> <dt>MPI</dt> <dd>Multiparton Interactions, i.e. several (more or less) independent parton-parton subcollisions as part of a hadron-hadron event (previously called MI for multiple interactions)</dd> <dt>MSSM</dt> <dd>Minimal Supersymmetric extension of the Standard Model</dd> <dt>PDF</dt> <dd>Parton Distribution Function (alternatively Parton Density Function)</dd> <dt>PDG code</dt> <dd>a scheme for assigning unique integers, particle identity codes, to known and hypothetical particles; code rules and tables are published in the RPP (see below).</dd> <dt>pileup</dt> <dd>several hadron-hadron collisions in a bunch crossing; not to be confused with MPI</dd> <dt>RPP</dt> <dd>Review of Particle Physics, the biannual review by the ParticleData Group (PDG) from which many Standard-Model parameter values and much particle data has been taken (but, given the poor data on many hadron resonances, a lot of extra (guess)work is needed)</dd> <dt>setting</dt> <dd>collectively used to denote all the boolean <code>flag</code>, integer <code>mode</code>, double-precision <code>parm</code> and string <code>word</code> variables that can be set by the user to steer the behaviour of a run; normally particle data are considered separately but clearly are closely related</dd> <dt>SLHA</dt> <dd>SUSY Les Houches Accord for interchange of mass and coupling information in SUSY scenarios, via a well-defined file format</dd> <dt>SM</dt> <dd>the Standard Model of particle physics</dd> <dt>SUSY</dt> <dd>SUperSYmmetry</dd> <dt>units</dt> <dd>Normal PYTHIA input, internal operations and output is based on a set of standard units, such as: <br/>GeV for all energies, momenta and masses, always with <i>c = 1</i>; <br/>mm for all distances and mm/<i>c</i> for all times, so that again they match for <i>c = 1</i>; <br/>mb for all cross sections (but input or output via the Les Houches Accord takes into account that the unit there is pb) </dd> </dl> </body> </html> <!-- Copyright (C) 2013 Torbjorn Sjostrand -->
