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first import of structure, PYTHIA8 and DELPHES
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1<html>
2<head>
3<title>Error Checks</title>
4<link rel="stylesheet" type="text/css" href="pythia.css"/>
5<link rel="shortcut icon" href="pythia32.gif"/>
6</head>
7<body>
8
9<h2>Error Checks</h2>
10
11There is a few settings related to error checking during program
12execution. Many other checks are performed as well, but do not
13have any specific setting related to themselves.
14
15<p/><code>flag&nbsp; </code><strong> Check:abortIfVeto &nbsp;</strong> 
16 (<code>default = <strong>off</strong></code>)<br/>
17There are a few ways in which an event can be vetoed, the most
18common being a <a href="UserHooks.html" target="page">User Hooks</a> test.
19Normally this will simply mean that the next parton-level
20configuration is selected inside the <code>Pythia::next()</code>
21routine, without any need for a user intervention. With this
22option switched on, however, <code>Pythia::next()</code> will
23return <code>false</code>. It is then up to the user to decide
24what to do next.
25 
26
27<p/><code>flag&nbsp; </code><strong> Check:particleData &nbsp;</strong> 
28 (<code>default = <strong>off</strong></code>)<br/>
29Check the particle data tables for potential problems during
30initialization. This includes inconsistent use of charge in particle
31names, inconsistent setup of mass, mass range, width and lifetime,
32sum of branching ratios not unity (allowed but discouraged) or charge
33not conserved in a decay channel. Warnings should be viewed as reasons
34to check further, but need not indicate a true problem, and also not all
35problems may be caught.
36The <code>pythia.particleData.checkTable(level)</code> method,
37used for these checks, may also be called directly.
38 
39
40<p/><code>mode&nbsp; </code><strong> Check:levelParticleData &nbsp;</strong> 
41 (<code>default = <strong>1</strong></code>)<br/>
42The level of verbosity and checks of particle data, if switched on.
43<br/><code>option </code><strong> 0</strong> : mimimal amount of checks, e.g. that no channels open.
44 
45<br/><code>option </code><strong> 1</strong> : further warning if individual channels closed,
46except for resonances. 
47<br/><code>option </code><strong> 2</strong> : also print branching-ratio-averaged threshold mass
48except for resonances. 
49<br/><code>option </code><strong> 11</strong> : as 1, but include resonances in detailed checks.
50 
51<br/><code>option </code><strong> 12</strong> : as 2, but include resonances in detailed checks.
52 
53 
54
55<p/><code>flag&nbsp; </code><strong> Check:event &nbsp;</strong> 
56 (<code>default = <strong>on</strong></code>)<br/>
57When an event has been successfully generated, check that the
58final event record in <code>event</code> does not contain any
59unphysical particles, or nonconserved charge or energy-momentum.
60If this check fails, then <code>pythia.next()</code> obtains the
61value <code>false</code>, i.e. the event is counted as aborted.
62 
63
64<p/><code>flag&nbsp; </code><strong> Check:history &nbsp;</strong> 
65 (<code>default = <strong>on</strong></code>)<br/>
66When <code>Check:event = on</code> and the event is checked as above,
67further checks are made that all mother and daughter pointers are
68consistently set. Specifically that all daughters in the
69<code>daughterlist</code> (or <code>motherList</code>) have the
70particle in their respective <code>motherList</code>
71(or <code>daughterlist</code>). This operation takes a bit more
72time than the other error tests (of the order of 10% of what it takes
73to generate the event in the first place), and so could be switched off
74to save time.
75 
76
77
78<p/><code>mode&nbsp; </code><strong> Check:nErrList &nbsp;</strong> 
79 (<code>default = <strong>0</strong></code>)<br/>
80The number of erroneous events, in the above check, for which
81event listing and other detailed information will be printed.
82After that, only the normal error messages will be issued.
83Error counters are always updated, and accumulated numbers can be   
84shown with <code>pythia.statistics()</code> at the end of the run.
85 
86
87<p/><code>parm&nbsp; </code><strong> Check:epTolErr &nbsp;</strong> 
88 (<code>default = <strong>1e-4</strong></code>)<br/>
89Maximum allowed summed deviation of <i>E</i>, <i>p_x</i>,
90<i>p_y</i> and <i>p_z</i> between the incoming beams and the
91final state, as a fraction of the initial energy, above which the
92event is counted as aborted.
93(Unfortunetely roundoff errors do not scale linearly with the energy,
94and also have a very long tail. So while most events at lower energies
95may be correct to better than 1e-10, at LHC it does not have to signal
96any fundamental bug if also the default tolerance above is violated
97occasionally.)
98 
99
100<p/><code>parm&nbsp; </code><strong> Check:epTolWarn &nbsp;</strong> 
101 (<code>default = <strong>1e-6</strong></code>)<br/>
102A check on the same summed deviation as above, but counted as a
103warning rather than an error, and not leading to the event being
104classified as aborted.
105 
106
107</body>
108</html>
109
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