<chapter name="Glossary"> 
 
<h2>Glossary</h2> 
 
<dl> 
 
<dt>BR</dt> 
<dd>Beam Remnants; not much used since it may be confused with 
Branching Ratio; sometimes called beam-beam remnants, BBR</dd> 
 
<dt>BSM</dt> 
<dd>Beyond-the-Standard-Model physics, as a generic term for anything 
not contained within the SM</dd> 
 
<dt>CR</dt> 
<dd>Colour Reconnection</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 <ei>c = 1</ei>; 
<br/>mm for all distances and mm/<ei>c</ei> for all times, 
so that again they match for <ei>c = 1</ei>; 
<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> 
 
</chapter> 
 
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