/usr/share/doc/pythia8-doc/html/MasterSwitches.html is in pythia8-doc-html 8.1.80-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 | <html>
<head>
<title>Master Switches</title>
<link rel="stylesheet" type="text/css" href="pythia.css"/>
<link rel="shortcut icon" href="pythia32.gif"/>
</head>
<body>
<h2>Master Switches</h2>
Sometimes it may be convenient to omit certain aspects of the event
generation chain. This cannot be motivated in a full-blown production
run, but can often be convenient for own understanding and for
debug purposes. The flags on this page allow just that.
<p/>
The event generation is subdivided into three levels: the process
level, the parton level and the hadron level, and flags are grouped
accordingly.
<h3>Process Level</h3>
The <code>ProcessLevel</code> class administrates the initial step of
the event generation, wherein the basic process is selected. Currently
this is done either using some of the internal processes, or with
Les Houches Accord input.
<p/>
There could not be a complete event without an initial process, so
it would not be a normal action to switch off this step. Furthermore,
without a process set, it is also not possible to carry out the tasks
on the parton level. It is still possible, however, to hadronize
a parton-level configuration provided by some external program.
<p/><code>flag </code><strong> ProcessLevel:all </strong>
(<code>default = <strong>on</strong></code>)<br/>
If off, do not attempt to carry out any generation at all on the
process level. For the parton level only final-state radiation
is possible, using the <code>Pythia::forceTimeShower(...)</code> method.
Do allow parton configurations stored in the event record to hadronize
and hadrons to decay, however, as set by the <code>HadronLevel</code>
switches. Further details are found
<a href="HadronLevelStandalone.html" target="page">here</a>.
<p/>
For <code>ProcessLevel:all = on</code> one part of the event generation
on this level may be switched off individually:
<p/><code>flag </code><strong> ProcessLevel:resonanceDecays </strong>
(<code>default = <strong>on</strong></code>)<br/>
Master switch to allow resonance decays; on/off = true/false.
Normal hadrons and leptons do not count as resonances, so this is
aimed specifically towards <i>Z^0, W^+-, t, h^0</i> and similar
objects beyond the Standard Model. Do not use this option if you
may produce coloured resonances and intend to allow hadronization,
since currently the program would not know how to handle this.
<p/>
It is possible to stop the generation immediately after the basic
process has been selected, see <code>PartonLevel:all</code> below.
<h3>PartonLevel</h3>
The <code>PartonLevel</code> class administrates the middle step of the
event generation, i.e. the evolution from an input (hard) process from
<code>ProcessLevel</code>, containing a few partons only, to a complete
parton-level configuration to be handed on to <code>HadronLevel</code>.
This step involves the application of initial- and final-state radiation,
multiparton interactions and the structure of beam remnants.
<p/><code>flag </code><strong> PartonLevel:all </strong>
(<code>default = <strong>on</strong></code>)<br/>
If off then stop the generation after the hard process has been
generated, but before the parton-level and hadron-level steps.
The <code>process</code> record is filled, but the <code>event</code>
one is then not.
<p/>
For <code>PartonLevel:all = on</code> some parts of the event generation
on this level may be switched off individually:
<p/><code>flag </code><strong> PartonLevel:MPI </strong>
(<code>default = <strong>on</strong></code>)<br/>
Master switch for multiparton interactions; on/off = true/false.
Further options are found <a href="MultipartonInteractions.html" target="page">here</a>.
<p/><code>flag </code><strong> PartonLevel:ISR </strong>
(<code>default = <strong>on</strong></code>)<br/>
Master switch for initial-state radiation; on/off = true/false.
Further options are found <a href="SpacelikeShowers.html" target="page">here</a>.
<p/><code>flag </code><strong> PartonLevel:FSR </strong>
(<code>default = <strong>on</strong></code>)<br/>
Master switch for final-state radiation; on/off = true/false.
Further options are found <a href="TimelikeShowers.html" target="page">here</a>.
If you leave this switch on, the following two switches allow
more detailed control to switch off only parts of the showers.
<p/><code>flag </code><strong> PartonLevel:FSRinProcess </strong>
(<code>default = <strong>on</strong></code>)<br/>
Switch for final-state radiation in association with the hard process
itself; on/off = true/false. In addition <code>PartonLevel:FSR</code>
must be on for these emissions to occur.
<p/><code>flag </code><strong> PartonLevel:FSRinResonances </strong>
(<code>default = <strong>on</strong></code>)<br/>
Master switch for final-state radiation in any resonance decays
subsequent to the hard process itself; on/off = true/false. In addition
<code>PartonLevel:FSR</code> must be on for these emissions to occur.
<p/><code>flag </code><strong> PartonLevel:earlyResDec </strong>
(<code>default = <strong>off</strong></code>)<br/>
If on then do resonance decays early, before beam handling including
colour reconnection. If off then decays are done afterwards, and so
are unaffected by colour reconnection. The early-decay option is still
primitive, for some first studies. Eventually the choice should be
made individually for each resonance based on lifetime (and the
environment).
<p/>
Switching off all the above MPI/ISR/FSR switches is <b>not</b> equivalent
to setting <code>PartonLevel:all = off</code>. In the former case a
minimal skeleton of parton-level operations are carried out, such as
tying together the scattered partons with the beam remnants into colour
singlets, and storing this information in the <code>event</code> record.
It is therefore possible to go on and hadronize the event, if desired.
In the latter case <b>no</b> operations at all are carried out on the
parton level, and therefore it is also not possible to go on to the
hadron level.
<p/><code>flag </code><strong> PartonLevel:Remnants </strong>
(<code>default = <strong>on</strong></code>)<br/>
Master switch for addition of beam remnants; on/off = true/false.
Only intended for very special applications, and cannot be used to
generate complete events. Specifically, unlike the other switches above,
the program will complain and possibly crash unlike you also set
<code>HadronLevel:all = off</code> and <code>Check:event = off</code>.
<p/>
It is possible to stop the generation immediately after the parton level
has been set up, see <code>HadronLevel:all</code> below.
<h3>HadronLevel</h3>
The <code>HadronLevel</code> class administrates the final step of the
event generation, wherein the partonic configuration from
<code>PartonLevel</code> is hadronized, including string fragmentation
and secondary decays.
<p/>
Most of the code in this class itself deals with subdividing the partonic
content of the event into separate colour singlets, that can be
treated individually by the string fragmentation machinery. When a
junction and an antijunction are directly connected, it also breaks
the string between the two, so that the topology can be reduced back
to two separate one-junction systems, while still preserving the
expected particle flow in the junction-junction string region(s).
<p/><code>flag </code><strong> HadronLevel:all </strong>
(<code>default = <strong>on</strong></code>)<br/>
If off then stop the generation after the hard process and
parton-level activity has been generated, but before the
hadron-level steps.
<p/>
For <code>HadronLevel:all = on</code> some parts of the event generation
on this level may be switched off individually:
<p/><code>flag </code><strong> HadronLevel:Hadronize </strong>
(<code>default = <strong>on</strong></code>)<br/>
Master switch for hadronization; on/off = true/false.
Further options are found <a href="Fragmentation.html" target="page">here</a>.
<p/><code>flag </code><strong> HadronLevel:Decay </strong>
(<code>default = <strong>on</strong></code>)<br/>
Master switch for decays; on/off = true/false.
Further options are found <a href="ParticleDecays.html" target="page">here</a>.
<p/><code>flag </code><strong> HadronLevel:BoseEinstein </strong>
(<code>default = <strong>off</strong></code>)<br/>
Master switch for the simulation of Bose-Einstein effects;
on/off = true/false. Further options are found
<a href="BoseEinsteinEffects.html" target="page">here</a>.
<h3>Printing</h3>
<p/><code>flag </code><strong> Print:quiet </strong>
(<code>default = <strong>off</strong></code>)<br/>
Can be set on to avoid the printing during program execution, to the
largest extent possible. This flag acts by setting the relevant values
for <code>Init:showProcesses</code>,
<code>Init:showMultipartonInteractions</code>,
<code>Init:showChangedSettings</code>,
<code>Init:showAllSettings</code>,
<code>Init:showChangedParticleData</code>,
<code>Init:showChangedResonanceData</code>,
<code>Init:showAllParticleData</code>,
<code>Init:showOneParticleData</code>,
<code>Next:numberCount</code>,
<code>Next:numberShowLHA</code>,
<code>Next:numberShowInfo</code>,
<code>Next:numberShowProcess</code>, and
<code>Next:numberShowEvent</code>.
The change is to off or 0 for <code>Print:quiet = off</code>,
and restores to the respective default value for <code>= on</code>.
Those changes take effect immediately, so individual settings can be
changed afterwards.
</body>
</html>
<!-- Copyright (C) 2013 Torbjorn Sjostrand -->
|