Main-Program Settings

Introduction

The main program is up to the user to write. However, sample main programs are provided. In one such class of programs, one may wish to read in key settings of the run from a "cards file". In this file some such settings are defined, and made available inside the Settings machinery. They can thus be put among the other cards, and then read back in by the main program.

Run settings

Here comes a first batch of settings that can be set in an input "cards" file, and thereafter read out an used in the user-written main program. Usage is purely optional.

mode name="Main:numberOfEvents" default="1000" min="0"
The number of events to be generated.

mode name="Main:numberToList" default="2" min="0"
The number of events to list.

mode name="Main:timesToShow" default="50" min="0"
Print the number of events generated so far, this many times, i.e. once every numberOfEvents/numberToShow events.

mode name="Main:timesAllowErrors" default="10" min = "0"
Allow this many times that pythia.next() returns false, i.e. that an event is flawed, before aborting the run.

flag name="Main:showChangedSettings" default="on"
Print a list of the changed flag/mode/parameter/word settings.

flag name="Main:showAllSettings" default="off"
Print a list of all flag/mode/parameter/word settings.

flag name="Main:showChangedParticleData" default="off"
Print a list of particle and decay data for those particles that were changed (one way or another).

flag name="Main:showAllParticleData" default="off"
Print a list of all particle and decay data.

flag name="Main:writeChangedSettings" default="off"
Write a file with the changed flag/mode/parameter/word settings, in a format appropriate to be read in at the beginning of a new run, using the pythia.readFile("fileName") method.

word name="Main:changedSettingsFile" default="currentSettings.cmnd"
The name of the file to which the changed flag/mode/parameter/word settings are written if Main:writeChangedSettings is on.

flag name="Main:writeAllSettings" default="off"
Write a file with all flag/mode/parameter/word settings, in a format appropriate to be read in at the beginning of a new run, using the pythia.readFile("fileName") method.

word name="Main:allSettingsFile" default="allSettings.cmnd"
The name of the file to which a flag/mode/parameter/word settings are written if Main:writeAllSettings is on.

flag name="Main:showAllStatistics" default="off"
Print all available statistics or only the minimal set at the end of the run.

Incoming beams

Normally the identities and energies of the two incoming beam particles are given by the arguments of the init call. These settings can be stored in an input "cards" file, in the following variables, and thereafter read out and used in the user-written main program. Usage is purely optional.

mode name="Main:idBeamA" default="2212"
The PDG id code for the first incoming particle.

mode name="Main:idBeamB" default="2212"
The PDG id code for the second incoming particle.

flag name="Main:inCMframe" default="on"
Assume collisions occur in the CM frame.

parm name="Main:eCM" default="1960." min="10."
Collision CM energy, to be given if Main:inCMframe is on.

parm name="Main:eBeamA" default="7000." min="0."
The energy of the first incoming particle, moving in the +z direction. If the particle energy is smaller than its mass it is assumed to be at rest.

parm name="Main:eBeamB" default="7000." min="0."
The energy of the second incoming particle, moving in the -z direction. If the particle energy is smaller than its mass it is assumed to be at rest.

Sample main programs

To help exemplify what a main program could look like, a few simple examples are provided:

Spares

For currently unforeseen purposes, a few dummy settings are made available here. The user can set the desired value in a "cards file" and then use that value in the main program as desired.

flag name="Main:spareFlag1" default="off"

flag name="Main:spareFlag2" default="off"

flag name="Main:spareFlag3" default="off"

mode name="Main:spareMode1" default="0"

mode name="Main:spareMode2" default="0"

mode name="Main:spareMode3" default="0"

parm name="Main:spareParm1" default="0."

parm name="Main:spareParm2" default="0."

parm name="Main:spareParm3" default="0."

word name="Main:spareWord1" default="void"

word name="Main:spareWord2" default="void"

word name="Main:spareWord3" default="void"