]>
Commit | Line | Data |
---|---|---|
c6b60c38 | 1 | <html> |
2 | <head> | |
3 | <title>Event Information</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 | <script language=javascript type=text/javascript> | |
10 | function stopRKey(evt) { | |
11 | var evt = (evt) ? evt : ((event) ? event : null); | |
12 | var node = (evt.target) ? evt.target :((evt.srcElement) ? evt.srcElement : null); | |
13 | if ((evt.keyCode == 13) && (node.type=="text")) | |
14 | {return false;} | |
15 | } | |
16 | ||
17 | document.onkeypress = stopRKey; | |
18 | </script> | |
19 | <?php | |
20 | if($_POST['saved'] == 1) { | |
21 | if($_POST['filepath'] != "files/") { | |
22 | echo "<font color='red'>SETTINGS SAVED TO FILE</font><br/><br/>"; } | |
23 | else { | |
24 | echo "<font color='red'>NO FILE SELECTED YET.. PLEASE DO SO </font><a href='SaveSettings.php'>HERE</a><br/><br/>"; } | |
25 | } | |
26 | ?> | |
27 | ||
28 | <form method='post' action='EventInformation.php'> | |
29 | ||
30 | <h2>Event Information</h2> | |
31 | ||
32 | The <code>Info</code> class collects various one-of-a-kind information, | |
33 | some relevant for all events and others for the current event. | |
34 | An object <code>info</code> is a public member of the <code>Pythia</code> | |
35 | class, so if you e.g. have declared <code>Pythia pythia</code>, the | |
36 | <code>Info</code> methods can be accessed by | |
37 | <code>pythia.info.method()</code>. Most of this is information that | |
38 | could also be obtained e.g. from the event record, but is here more | |
39 | directly available. It is primarily intended for processes generated | |
40 | internally in PYTHIA, but many of the methods would work also for | |
41 | events fed in via the Les Houches Accord. | |
42 | ||
43 | <h3>List information</h3> | |
44 | ||
45 | <a name="method1"></a> | |
46 | <p/><strong>void Info::list() </strong> <br/> | |
47 | a listing of most of the information set for the current event. | |
48 | ||
49 | ||
50 | <h3>The beams</h3> | |
51 | ||
52 | <a name="method2"></a> | |
53 | <p/><strong>int Info::idA() </strong> <br/> | |
54 | ||
55 | <strong>int Info::idB() </strong> <br/> | |
56 | the identities of the two beam particles. | |
57 | ||
58 | ||
59 | <a name="method3"></a> | |
60 | <p/><strong>double Info::pzA() </strong> <br/> | |
61 | ||
62 | <strong>double Info::pzB() </strong> <br/> | |
63 | the longitudinal momenta of the two beam particles. | |
64 | ||
65 | ||
66 | <a name="method4"></a> | |
67 | <p/><strong>double Info::eA() </strong> <br/> | |
68 | ||
69 | <strong>double Info::eB() </strong> <br/> | |
70 | the energies of the two beam particles. | |
71 | ||
72 | ||
73 | <a name="method5"></a> | |
74 | <p/><strong>double Info::mA() </strong> <br/> | |
75 | ||
76 | <strong>double Info::mB() </strong> <br/> | |
77 | the masses of the two beam particles. | |
78 | ||
79 | ||
80 | <a name="method6"></a> | |
81 | <p/><strong>double Info::eCM() </strong> <br/> | |
82 | ||
83 | <strong>double Info::s() </strong> <br/> | |
84 | the CM energy and its square for the two beams. | |
85 | ||
86 | ||
87 | <h3>Initialization</h3> | |
88 | ||
89 | <a name="method7"></a> | |
90 | <p/><strong>bool Info::tooLowPTmin() </strong> <br/> | |
91 | normally false, but true if the proposed <i>pTmin</i> scale was too low | |
92 | in timelike or spacelike showers, or in multiparton interactions. In the | |
93 | former case the <i>pTmin</i> is raised to some minimal value, in the | |
94 | latter the initialization fails (it is impossible to obtain a minijet | |
95 | cross section bigger than the nondiffractive one by reducing | |
96 | <i>pTmin</i>). | |
97 | ||
98 | ||
99 | <h3>The event type</h3> | |
100 | ||
101 | <a name="method8"></a> | |
102 | <p/><strong>string Info::name() </strong> <br/> | |
103 | ||
104 | <strong>int Info::code() </strong> <br/> | |
105 | the name and code of the process that occurred. | |
106 | ||
107 | ||
108 | <a name="method9"></a> | |
109 | <p/><strong>int Info::nFinal() </strong> <br/> | |
110 | the number of final-state partons in the hard process. | |
111 | ||
112 | ||
113 | <a name="method10"></a> | |
114 | <p/><strong>bool Info::isResolved() </strong> <br/> | |
115 | are beam particles resolved, i.e. were PDF's used for the process? | |
116 | ||
117 | ||
118 | <a name="method11"></a> | |
119 | <p/><strong>bool Info::isDiffractiveA() </strong> <br/> | |
120 | ||
121 | <strong>bool Info::isDiffractiveB() </strong> <br/> | |
122 | is either beam diffractively excited? | |
123 | ||
124 | ||
125 | <a name="method12"></a> | |
126 | <p/><strong>bool Info::isDiffractiveC() </strong> <br/> | |
127 | is there central diffraction (a.k.a. double Pomeron exchange)? | |
128 | ||
129 | ||
130 | <a name="method13"></a> | |
131 | <p/><strong>bool Info::isMinBias() </strong> <br/> | |
132 | is the process a minimum-bias one? | |
133 | ||
134 | ||
135 | <a name="method14"></a> | |
136 | <p/><strong>bool Info::isLHA() </strong> <br/> | |
137 | has the process been generated from external Les Houches Accord | |
138 | information? | |
139 | ||
140 | ||
141 | <a name="method15"></a> | |
142 | <p/><strong>bool Info::atEndOfFile() </strong> <br/> | |
143 | true if a linked Les Houches class refuses to return any further | |
144 | events, presumably because it has reached the end of the file from | |
145 | which events have been read in. | |
146 | ||
147 | ||
148 | <a name="method16"></a> | |
149 | <p/><strong>bool Info::hasSub() </strong> <br/> | |
150 | does the process have a subprocess classification? | |
151 | Currently only true for minbias and Les Houches events, where it allows | |
152 | the hardest collision to be identified. | |
153 | ||
154 | ||
155 | <a name="method17"></a> | |
156 | <p/><strong>string Info::nameSub() </strong> <br/> | |
157 | ||
158 | <strong>int Info::codeSub() </strong> <br/> | |
159 | ||
160 | <strong>int Info::nFinalSub() </strong> <br/> | |
161 | the name, code and number of final-state partons in the subprocess | |
162 | that occurred when <code>hasSub()</code> is true. For a minimum-bias event | |
163 | the <code>code</code> would always be 101, while <code>codeSub()</code> | |
164 | would vary depending on the actual hardest interaction, e.g. 111 for | |
165 | <i>g g -> g g</i>. For a Les Houches event the <code>code</code> would | |
166 | always be 9999, while <code>codeSub()</code> would be the external | |
167 | user-defined classification code. The methods below would also provide | |
168 | information for such particular subcollisions. | |
169 | ||
170 | ||
171 | <h3>Hard process initiators</h3> | |
172 | ||
173 | The methods in this sections refer to the two initial partons of the | |
174 | hard <i>2 -> n</i> process (diffraction excluded; see below). | |
175 | ||
176 | <a name="method18"></a> | |
177 | <p/><strong>int Info::id1() </strong> <br/> | |
178 | ||
179 | <strong>int Info::id2() </strong> <br/> | |
180 | the identities of the two partons coming in to the hard process. | |
181 | ||
182 | ||
183 | <a name="method19"></a> | |
184 | <p/><strong>double Info::x1() </strong> <br/> | |
185 | ||
186 | <strong>double Info::x2() </strong> <br/> | |
187 | <i>x</i> fractions of the two partons coming in to the hard process. | |
188 | ||
189 | ||
190 | <a name="method20"></a> | |
191 | <p/><strong>double Info::y() </strong> <br/> | |
192 | ||
193 | <strong>double Info::tau() </strong> <br/> | |
194 | rapidity and scaled mass-squared of the hard-process subsystem, as | |
195 | defined by the above <i>x</i> values. | |
196 | ||
197 | ||
198 | <a name="method21"></a> | |
199 | <p/><strong>bool Info::isValence1() </strong> <br/> | |
200 | ||
201 | <strong>bool Info::isValence2() </strong> <br/> | |
202 | <code>true</code> if the two hard incoming partons have been picked | |
203 | to belong to the valence piece of the parton-density distribution, | |
204 | else <code>false</code>. Should be interpreted with caution. | |
205 | Information is not set if you switch off parton-level processing. | |
206 | ||
207 | ||
208 | <h3>Hard process parton densities and scales</h3> | |
209 | ||
210 | The methods in this section refer to the partons for which parton | |
211 | densities have been defined, in order to calculate the cross section | |
212 | of the hard process (diffraction excluded; see below). | |
213 | ||
214 | <p/> | |
215 | These partons would normally agree with the | |
216 | ones above, the initiators of the <i>2 -> n</i> process, but it | |
217 | does not have to be so. Currently the one counterexample is POWHEG | |
218 | events [<a href="Bibliography.php" target="page">Ali10</a>]. Here the original hard process could be | |
219 | <i>2 -> (n-1)</i>. The NLO machinery at times would add an | |
220 | initial-state branching to give a <i>2 -> n</i> process with a | |
221 | changed initial state. In that case the values in this section | |
222 | refer to the original <i>2 -> (n-1)</i> state and the initiator | |
223 | ones above to the complete<i>2 -> n</i> process. The | |
224 | <code>Info::list()</code> printout will contain a warning in such cases. | |
225 | ||
226 | <p/> | |
227 | For external events in the Les Houches format, the pdf information | |
228 | is obtained from the optional <code>#pdf</code> line. When this | |
229 | information is absent, the parton identities and <i>x</i> values agree | |
230 | with the initiator ones above, while the pdf values are unknown and | |
231 | therefore set to vanish. The <i>alpha_s</i> and <i>alpha_em</i> | |
232 | values are part of the compulsory information. The factorization and | |
233 | renormalization scales are both equated with the one compulsory scale | |
234 | value in the Les Houches standard, except when a <code>#pdf</code> | |
235 | line provides the factorization scale separately. If <i>alpha_s</i>, | |
236 | <i>alpha_em</i> or the compulsory scale value are negative at input | |
237 | then new values are defined as for internal processes. | |
238 | ||
239 | <a name="method22"></a> | |
240 | <p/><strong>int Info::id1pdf() </strong> <br/> | |
241 | ||
242 | <strong>int Info::id2pdf() </strong> <br/> | |
243 | the identities of the two partons for which parton density values | |
244 | are defined. | |
245 | ||
246 | ||
247 | <a name="method23"></a> | |
248 | <p/><strong>double Info::x1pdf() </strong> <br/> | |
249 | ||
250 | <strong>double Info::x2pdf() </strong> <br/> | |
251 | <i>x</i> fractions of the two partons for which parton density values | |
252 | are defined. | |
253 | ||
254 | ||
255 | <a name="method24"></a> | |
256 | <p/><strong>double Info::pdf1() </strong> <br/> | |
257 | ||
258 | <strong>double Info::pdf2() </strong> <br/> | |
259 | parton densities <i>x*f(x,Q^2)</i> evaluated for the two incoming | |
260 | partons; could be used e.g. for reweighting purposes in conjunction | |
261 | with the <code>idpdf</code>, <code>xpdf</code> and <code>QFac</code> | |
262 | methods. Events obtained from external programs or files may not | |
263 | contain this information and, if so, 0 is returned. | |
264 | ||
265 | ||
266 | <a name="method25"></a> | |
267 | <p/><strong>double Info::QFac() </strong> <br/> | |
268 | ||
269 | <strong>double Info::Q2Fac() </strong> <br/> | |
270 | the <i>Q</i> or <i>Q^2</i> factorization scale at which the | |
271 | densities were evaluated. | |
272 | ||
273 | ||
274 | <a name="method26"></a> | |
275 | <p/><strong>double Info::alphaS() </strong> <br/> | |
276 | ||
277 | <strong>double Info::alphaEM() </strong> <br/> | |
278 | the <i>alpha_strong</i> and <i>alpha_electromagnetic</i> values used | |
279 | for the hard process. | |
280 | ||
281 | ||
282 | <a name="method27"></a> | |
283 | <p/><strong>double Info::QRen() </strong> <br/> | |
284 | ||
285 | <strong>double Info::Q2Ren() </strong> <br/> | |
286 | the <i>Q</i> or <i>Q^2</i> renormalization scale at which | |
287 | <i>alpha_strong</i> and <i>alpha_electromagnetic</i> were evaluated. | |
288 | ||
289 | ||
290 | <h3>Hard process kinematics</h3> | |
291 | ||
292 | The methods in this section provide info on the kinematics of the hard | |
293 | processes, with special emphasis on <i>2 -> 2</i> (diffraction excluded; | |
294 | see below). | |
295 | ||
296 | <a name="method28"></a> | |
297 | <p/><strong>double Info::mHat() </strong> <br/> | |
298 | ||
299 | <strong>double Info::sHat() </strong> <br/> | |
300 | the invariant mass and its square for the hard process. | |
301 | ||
302 | ||
303 | <a name="method29"></a> | |
304 | <p/><strong>double Info::tHat() </strong> <br/> | |
305 | ||
306 | <strong>double Info::uHat() </strong> <br/> | |
307 | the remaining two Mandelstam variables; only defined for <i>2 -> 2</i> | |
308 | processes. | |
309 | ||
310 | ||
311 | <a name="method30"></a> | |
312 | <p/><strong>double Info::pTHat() </strong> <br/> | |
313 | ||
314 | <strong>double Info::pT2Hat() </strong> <br/> | |
315 | transverse momentum and its square in the rest frame of a <i>2 -> 2</i> | |
316 | processes. | |
317 | ||
318 | ||
319 | <a name="method31"></a> | |
320 | <p/><strong>double Info::m3Hat() </strong> <br/> | |
321 | ||
322 | <strong>double Info::m4Hat() </strong> <br/> | |
323 | the masses of the two outgoing particles in a <i>2 -> 2</i> processes. | |
324 | ||
325 | ||
326 | <a name="method32"></a> | |
327 | <p/><strong>double Info::thetaHat() </strong> <br/> | |
328 | ||
329 | <strong>double Info::phiHat() </strong> <br/> | |
330 | the polar and azimuthal scattering angles in the rest frame of | |
331 | a <i>2 -> 2</i> process. | |
332 | ||
333 | ||
334 | <h3>Diffraction</h3> | |
335 | ||
336 | Information on the primary elastic or | |
337 | <?php $filepath = $_GET["filepath"]; | |
338 | echo "<a href='Diffraction.php?filepath=".$filepath."' target='page'>";?>diffractive</a> process | |
339 | (<i>A B -> A B, X1 B, A X2, X1 X2, A X B</i>) can be obtained with | |
340 | the methods in the "Hard process kinematics" section above. The | |
341 | variables here obviously are <i>s, t, u, ...</i> rather than | |
342 | <i>sHat, tHat, uHat, ...</i>, but the method names remain to avoid | |
343 | unnecessary duplication. Most other methods are irrelevant for a | |
344 | primary elastic/diffractive process. | |
345 | ||
346 | <p/>Central diffraction <i>A B -> A X B</i> is a <i>2 -> 3</i> | |
347 | process, and therefore most of the <i>2 -> 2</i> variables are | |
348 | no longer relevant. The <code>tHat()</code> and <code>uHat()</code> | |
349 | methods instead return the two <i>t</i> values at the <i>A -> A</i> | |
350 | and <i>B -> B</i> vertices, and <code>pTHat()</code> the average | |
351 | transverse momentum of the three outgoing "particles", while | |
352 | <code>thetaHat()</code> and <code>phiHat()</code> are undefined. | |
353 | ||
354 | <p/> | |
355 | While the primary interaction does not contain a hard process, | |
356 | the diffractive subsystems can contain them, but need not. | |
357 | Specifically, double diffraction can contain two separate hard | |
358 | subprocesses, which breaks the methods above. Most of them have been | |
359 | expanded with an optional argument to address properties of diffractive | |
360 | subsystems. This argument can take four values: | |
361 | <ul> | |
362 | <li>0 : default argument, used for normal nondiffractive events or | |
363 | the primary elastic/diffractive process (see above); | |
364 | <li>1 : the <i>X1</i> system in single diffraction <i>A B -> X1 B</i> | |
365 | or double diffraction <i>A B -> X1 X2</i>; | |
366 | <li>2 : the <i>X2</i> system in single diffraction <i>A B -> A X2</i> | |
367 | or double diffraction <i>A B -> X1 X2</i>; | |
368 | <li>3 : the <i>X</i> system in central diffraction <i>A B -> A X B</i>. | |
369 | </ul> | |
370 | The argument is defined for all of the methods in the three sections above, | |
371 | "Hard process initiators", "Hard process parton densities and scales" and | |
372 | "Hard process kinematics", with the exception of the <code>isValence</code> | |
373 | methods. Also the four final methods of "The event type" section, the | |
374 | <code>...Sub()</code> methods, take this argument. But recall that they | |
375 | will only provide meaningful answers, firstly if there is a system of the | |
376 | requested type, and secondly if there is a hard subprocess in this system. | |
377 | A simple check for this is that <code>id1()</code> has to be nonvanishing. | |
378 | The methods below this section do not currently provide information | |
379 | specific to diffractive subsystems, e.g. the MPI information is not | |
380 | bookkept in such cases. | |
381 | ||
382 | <h3>Event weight and activity</h3> | |
383 | ||
384 | <a name="method33"></a> | |
385 | <p/><strong>double Info::weight() </strong> <br/> | |
386 | weight assigned to the current event. Is normally 1 and thus | |
387 | uninteresting. However, there are several cases where one may have | |
388 | nontrivial event weights. These weights must the be used e.g. when | |
389 | filling histograms. | |
390 | <br/>(i) In the <code><?php $filepath = $_GET["filepath"]; | |
391 | echo "<a href='PhaseSpaceCuts.php?filepath=".$filepath."' target='page'>";?> | |
392 | PhaseSpace:increaseMaximum = off</a></code> default strategy, | |
393 | an event with a differential cross-section above the assumed one | |
394 | (in a given phase-space point) is assigned a weight correspondingly | |
395 | above unity. This should happen only very rarely, if at all, and so | |
396 | could normally be disregarded. | |
397 | <br/>(ii) The <?php $filepath = $_GET["filepath"]; | |
398 | echo "<a href='UserHooks.php?filepath=".$filepath."' target='page'>";?>User Hooks</a> class offers | |
399 | the possibility to bias the selection of phase space points, which | |
400 | means that events come with a compensating weight, stored here. | |
401 | <br/>(iii) For Les Houches events some strategies allow negative weights, | |
402 | which then after unweighting lead to events with weight -1. There are | |
403 | also Les Houches strategies where no unweighting is done, so events | |
404 | come with a weight. Specifically, for strategies <i>+4</i> and | |
405 | <i>-4</i>, the event weight is in units of pb. (Internally in mb, | |
406 | but converted at output.) | |
407 | ||
408 | ||
409 | <a name="method34"></a> | |
410 | <p/><strong>double Info::weightSum() </strong> <br/> | |
411 | Sum of weights accumulated during the run. For unweighted events this | |
412 | agrees with the number of generated events. In order to obtain | |
413 | histograms normalized "per event", at the end of a run, histogram | |
414 | contents should be divided by this weight. (And additionally | |
415 | divided by the bin width.) Normalization to cross section also | |
416 | required multiplication by <code>sigmaGen()</code> below. | |
417 | ||
418 | ||
419 | <a name="method35"></a> | |
420 | <p/><strong>int Info::lhaStrategy() </strong> <br/> | |
421 | normally 0, but if Les Houches events are input then it gives the | |
422 | event weighting strategy, see | |
423 | <?php $filepath = $_GET["filepath"]; | |
424 | echo "<a href='LesHouchesAccord.php?filepath=".$filepath."' target='page'>";?>Les Houches Accord</a>. | |
425 | ||
426 | ||
427 | <a name="method36"></a> | |
428 | <p/><strong>int Info::nISR() </strong> <br/> | |
429 | ||
430 | <strong>int Info::nFSRinProc() </strong> <br/> | |
431 | ||
432 | <strong>int Info::nFSRinRes() </strong> <br/> | |
433 | the number of emissions in the initial-state showering, in the final-state | |
434 | showering excluding resonance decays, and in the final-state showering | |
435 | inside resonance decays, respectively. | |
436 | ||
437 | ||
438 | <a name="method37"></a> | |
439 | <p/><strong>double Info::pTmaxMPI() </strong> <br/> | |
440 | ||
441 | <strong>double Info::pTmaxISR() </strong> <br/> | |
442 | ||
443 | <strong>double Info::pTmaxFSR() </strong> <br/> | |
444 | Maximum <i>pT</i> scales set for MPI, ISR and FSR, given the | |
445 | process type and scale choice for the hard interactions. The actual | |
446 | evolution will run down from these scales. | |
447 | ||
448 | ||
449 | <a name="method38"></a> | |
450 | <p/><strong>double Info::pTnow() </strong> <br/> | |
451 | The current <i>pT</i> scale in the combined MPI, ISR and FSR evolution. | |
452 | Useful for classification in <?php $filepath = $_GET["filepath"]; | |
453 | echo "<a href='UserHooks.php?filepath=".$filepath."' target='page'>";?>user hooks</a>, | |
454 | but not once the event has been evolved. | |
455 | ||
456 | ||
457 | <a name="method39"></a> | |
458 | <p/><strong>double Info::mergingWeight() </strong> <br/> | |
459 | combined leading-order merging weight assigned to the current event, if | |
460 | tree-level multi-jet merging (i.e. | |
461 | <a href="CKKWLMerging.html" target="page"> CKKW-L</a> or | |
462 | <a href="UMEPSMerging.html" target="page"> UMEPS</a> merging) is attempted. If | |
463 | tree-level multi-jet merging is | |
464 | performed, all histograms should be filled with this weight, as discussed in | |
465 | <a href="CKKWLMerging.html" target="page"> CKKW-L Merging</a> and | |
466 | <a href="UMEPSMerging.html" target="page"> UMEPS Merging</a>. | |
467 | ||
468 | ||
469 | <a name="method40"></a> | |
470 | <p/><strong>double Info::mergingWeightNLO() </strong> <br/> | |
471 | combined NLO merging weight assigned to the current event, if | |
472 | NLO multi-jet merging (i.e. | |
473 | <a href="NLOMerging.html" target="page"> NL<sup>3</sup></a> or | |
474 | <a href="NLOMerging.html" target="page"> UNLOPS</a> merging) is attempted. If | |
475 | NLO multi-jet merging is | |
476 | performed, all histograms should be filled with this weight, as discussed in | |
477 | <a href="NLOMerging.html" target="page"> NLO Merging</a> . | |
478 | ||
479 | ||
480 | <h3>Multiparton interactions</h3> | |
481 | ||
482 | <a name="method41"></a> | |
483 | <p/><strong>double Info::a0MPI() </strong> <br/> | |
484 | The value of a0 when an x-dependent matter profile is used, | |
485 | <code>MultipartonInteractions:bProfile = 4</code>. | |
486 | ||
487 | ||
488 | <a name="method42"></a> | |
489 | <p/><strong>double Info::bMPI() </strong> <br/> | |
490 | The impact parameter <i>b</i> assumed for the current collision when | |
491 | multiparton interactions are simulated. Is not expressed in any physical | |
492 | size (like fm), but only rescaled so that the average should be unity | |
493 | for minimum-bias events (meaning less than that for events with hard | |
494 | processes). | |
495 | ||
496 | ||
497 | <a name="method43"></a> | |
498 | <p/><strong>double Info::enhanceMPI() </strong> <br/> | |
499 | The choice of impact parameter implies an enhancement or depletion of | |
500 | the rate of subsequent interactions, as given by this number. Again | |
501 | the average is normalized be unity for minimum-bias events (meaning | |
502 | more than that for events with hard processes). | |
503 | ||
504 | ||
505 | <a name="method44"></a> | |
506 | <p/><strong>int Info::nMPI() </strong> <br/> | |
507 | The number of hard interactions in the current event. Is 0 for elastic | |
508 | and diffractive events, and else at least 1, with more possible from | |
509 | multiparton interactions. | |
510 | ||
511 | ||
512 | <a name="method45"></a> | |
513 | <p/><strong>int Info::codeMPI(int i) </strong> <br/> | |
514 | ||
515 | <strong>double Info::pTMPI(int i) </strong> <br/> | |
516 | the process code and transverse momentum of the <code>i</code>'th | |
517 | subprocess, with <code>i</code> in the range from 0 to | |
518 | <code>nMPI() - 1</code>. The values for subprocess 0 is redundant with | |
519 | information already provided above. | |
520 | ||
521 | ||
522 | <a name="method46"></a> | |
523 | <p/><strong>int Info::iAMPI(int i) </strong> <br/> | |
524 | ||
525 | <strong>int Info::iBMPI(int i) </strong> <br/> | |
526 | are normally zero. However, if the <code>i</code>'th subprocess is | |
527 | a rescattering, i.e. either or both incoming partons come from the | |
528 | outgoing state of previous scatterings, they give the position in the | |
529 | event record of the outgoing-state parton that rescatters. | |
530 | <code>iAMPI</code> and <code>iBMPI</code> then denote partons coming from | |
531 | the first or second beam, respectively. | |
532 | ||
533 | ||
534 | <a name="method47"></a> | |
535 | <p/><strong>double Info::eMPI(int i) </strong> <br/> | |
536 | The enhancement or depletion of the rate of the <code>i</code>'th | |
537 | subprocess. Is primarily of interest for the | |
538 | <code>MultipartonInteractions:bProfile = 4</code> option, where the | |
539 | size of the proton depends on the <i>x</i> values of the colliding | |
540 | partons. Note that <code>eMPI(0) = enhanceMPI()</code>. | |
541 | ||
542 | ||
543 | <h3>Cross sections</h3> | |
544 | ||
545 | Here are the currently available methods related to the event sample | |
546 | as a whole, for the default value <code>i = 0</code>, and otherwise for | |
547 | the specific process code provided as argument. This is the number | |
548 | obtained with <code>Info::code()</code>, while the further subdivision | |
549 | given by <code>Info::codeSub()</code> is not bookkept. While continuously | |
550 | updated during the run, it is recommended only to study these properties | |
551 | at the end of the event generation, when the full statistics is available. | |
552 | The individual process results are not available if | |
553 | <?php $filepath = $_GET["filepath"]; | |
554 | echo "<a href='ASecondHardProcess.php?filepath=".$filepath."' target='page'>";?>a second hard process</a> has been | |
555 | chosen, but can be gleaned from the <code>pythia.stat()</code> output. | |
556 | ||
557 | <a name="method48"></a> | |
558 | <p/><strong>long Info::nTried(int i = 0) </strong> <br/> | |
559 | ||
560 | <strong>long Info::nSelected(int i = 0) </strong> <br/> | |
561 | ||
562 | <strong>long Info::nAccepted(int i = 0) </strong> <br/> | |
563 | the total number of tried phase-space points, selected hard processes | |
564 | and finally accepted events, summed over all allowed processes | |
565 | (<code>i = 0</code>) or for the given process. | |
566 | The first number is only intended for a study of the phase-space selection | |
567 | efficiency. The last two numbers usually only disagree if the user introduces | |
568 | some veto during the event-generation process; then the former is the number | |
569 | of acceptable events found by PYTHIA and the latter the number that also | |
570 | were approved by the user. If you set <?php $filepath = $_GET["filepath"]; | |
571 | echo "<a href='ASecondHardProcess.php?filepath=".$filepath."' target='page'>";?>a | |
572 | second hard process</a> there may also be a mismatch. | |
573 | ||
574 | ||
575 | <a name="method49"></a> | |
576 | <p/><strong>double Info::sigmaGen(int i = 0) </strong> <br/> | |
577 | ||
578 | <strong>double Info::sigmaErr(int i = 0) </strong> <br/> | |
579 | the estimated cross section and its estimated error, | |
580 | summed over all allowed processes (<code>i = 0</code>) or for the given | |
581 | process, in units of mb. The numbers refer to the accepted event sample | |
582 | above, i.e. after any user veto. | |
583 | ||
584 | ||
585 | <h3>Loop counters</h3> | |
586 | ||
587 | Mainly for internal/debug purposes, a number of loop counters from | |
588 | various parts of the program are stored in the <code>Info</code> class, | |
589 | so that one can keep track of how the event generation is progressing. | |
590 | This may be especially useful in the context of the | |
591 | <code><?php $filepath = $_GET["filepath"]; | |
592 | echo "<a href='UserHooks.php?filepath=".$filepath."' target='page'>";?>User Hooks</a></code> facility. | |
593 | ||
594 | <a name="method50"></a> | |
595 | <p/><strong>int Info::getCounter(int i) </strong> <br/> | |
596 | the method that gives you access to the value of the various loop | |
597 | counters. | |
598 | <br/><code>argument</code><strong> i </strong> : the counter number you want to access: | |
599 | <br/><code>argumentoption </code><strong> 0 - 9</strong> : counters that refer to the run as a whole, | |
600 | i.e. are set 0 at the beginning of the run and then only can increase. | |
601 | ||
602 | <br/><code>argumentoption </code><strong> 0</strong> : the number of successful constructor calls for the | |
603 | <code>Pythia</code> class (can only be 0 or 1). | |
604 | ||
605 | <br/><code>argumentoption </code><strong> 1</strong> : the number of times a <code>Pythia::init(...)</code> | |
606 | call has been begun. | |
607 | ||
608 | <br/><code>argumentoption </code><strong> 2</strong> : the number of times a <code>Pythia::init(...)</code> | |
609 | call has been completed successfully. | |
610 | ||
611 | <br/><code>argumentoption </code><strong> 3</strong> : the number of times a <code>Pythia::next()</code> | |
612 | call has been begun. | |
613 | ||
614 | <br/><code>argumentoption </code><strong> 4</strong> : the number of times a <code>Pythia::next()</code> | |
615 | call has been completed successfully. | |
616 | ||
617 | <br/><code>argumentoption </code><strong> 10 - 19</strong> : counters that refer to each individual event, | |
618 | and are reset and updated in the top-level <code>Pythia::next()</code> | |
619 | method. | |
620 | ||
621 | <br/><code>argumentoption </code><strong> 10</strong> : the number of times the selection of a new hard | |
622 | process has been begun. Normally this should only happen once, unless a | |
623 | user veto is set to abort the current process and try a new one. | |
624 | ||
625 | <br/><code>argumentoption </code><strong> 11</strong> : the number of times the selection of a new hard | |
626 | process has been completed successfully. | |
627 | ||
628 | <br/><code>argumentoption </code><strong> 12</strong> : as 11, but additionally the process should | |
629 | survive any user veto and go on to the parton- and hadron-level stages. | |
630 | ||
631 | <br/><code>argumentoption </code><strong> 13</strong> : as 11, but additionally the process should | |
632 | survive the parton- and hadron-level stage and any user cuts. | |
633 | ||
634 | <br/><code>argumentoption </code><strong> 14</strong> : the number of times the loop over parton- and | |
635 | hadron-level processing has begun for a hard process. Is reset each | |
636 | time counter 12 above is reached. | |
637 | ||
638 | <br/><code>argumentoption </code><strong> 15</strong> : the number of times the above loop has successfully | |
639 | completed the parton-level step. | |
640 | ||
641 | <br/><code>argumentoption </code><strong> 16</strong> : the number of times the above loop has successfully | |
642 | completed the checks and user vetoes after the parton-level step. | |
643 | ||
644 | <br/><code>argumentoption </code><strong> 17</strong> : the number of times the above loop has successfully | |
645 | completed the hadron-level step. | |
646 | ||
647 | <br/><code>argumentoption </code><strong> 18</strong> : the number of times the above loop has successfully | |
648 | completed the checks and user vetoes after the hadron-level step. | |
649 | ||
650 | <br/><code>argumentoption </code><strong> 20 - 39</strong> : counters that refer to a local part of the | |
651 | individual event, and are reset at the beginning of this part. | |
652 | ||
653 | <br/><code>argumentoption </code><strong> 20</strong> : the current system being processed in | |
654 | <code>PartonLevel::next()</code>. Is almost always 1, but for double | |
655 | diffraction the two diffractive systems are 1 and 2, respectively. | |
656 | ||
657 | <br/><code>argumentoption </code><strong> 21</strong> : the number of times the processing of the | |
658 | current system (see above) has begun. | |
659 | ||
660 | <br/><code>argumentoption </code><strong> 22</strong> : the number of times a step has begun in the | |
661 | combined MPI/ISR/FSR evolution downwards in <i>pT</i> | |
662 | for the current system. | |
663 | ||
664 | <br/><code>argumentoption </code><strong> 23</strong> : the number of times MPI has been selected for the | |
665 | downwards step above. | |
666 | ||
667 | <br/><code>argumentoption </code><strong> 24</strong> : the number of times ISR has been selected for the | |
668 | downwards step above. | |
669 | ||
670 | <br/><code>argumentoption </code><strong> 25</strong> : the number of times FSR has been selected for the | |
671 | downwards step above. | |
672 | ||
673 | <br/><code>argumentoption </code><strong> 26</strong> : the number of times MPI has been accepted as the | |
674 | downwards step above, after the vetoes. | |
675 | ||
676 | <br/><code>argumentoption </code><strong> 27</strong> : the number of times ISR has been accepted as the | |
677 | downwards step above, after the vetoes. | |
678 | ||
679 | <br/><code>argumentoption </code><strong> 28</strong> : the number of times FSR has been accepted as the | |
680 | downwards step above, after the vetoes. | |
681 | ||
682 | <br/><code>argumentoption </code><strong> 29</strong> : the number of times a step has begun in the | |
683 | separate (optional) FSR evolution downwards in <i>pT</i> | |
684 | for the current system. | |
685 | ||
686 | <br/><code>argumentoption </code><strong> 30</strong> : the number of times FSR has been selected for the | |
687 | downwards step above. | |
688 | ||
689 | <br/><code>argumentoption </code><strong> 31</strong> : the number of times FSR has been accepted as the | |
690 | downwards step above, after the vetoes. | |
691 | ||
692 | <br/><code>argumentoption </code><strong> 40 - 49</strong> : counters that are unused (currently), and | |
693 | that therefore are free to use, with the help of the two methods below. | |
694 | ||
695 | ||
696 | ||
697 | ||
698 | <a name="method51"></a> | |
699 | <p/><strong>void Info::setCounter(int i, int value = 0) </strong> <br/> | |
700 | set the above counters to a given value. Only to be used by you | |
701 | for the unassigned counters 40 - 49. | |
702 | <br/><code>argument</code><strong> i </strong> : the counter number, see above. | |
703 | ||
704 | <br/><code>argument</code><strong> value </strong> (<code>default = <strong>0</strong></code>) : set the counter to this number; | |
705 | normally the default value is what you want. | |
706 | ||
707 | ||
708 | ||
709 | <a name="method52"></a> | |
710 | <p/><strong>void Info::addCounter(int i, int value = 0) </strong> <br/> | |
711 | increase the above counters by a given amount. Only to be used by you | |
712 | for the unassigned counters 40 - 49. | |
713 | <br/><code>argument</code><strong> i </strong> : the counter number, see above. | |
714 | ||
715 | <br/><code>argument</code><strong> value </strong> (<code>default = <strong>1</strong></code>) : increase the counter by this amount; | |
716 | normally the default value is what you want. | |
717 | ||
718 | ||
719 | ||
720 | <h3>Parton shower history</h3> | |
721 | ||
722 | The following methods are mainly intended for internal use, | |
723 | e.g. for matrix-element matching. | |
724 | ||
725 | <a name="method53"></a> | |
726 | <p/><strong>void Info::hasHistory(bool hasHistoryIn) </strong> <br/> | |
727 | ||
728 | <strong>bool Info::hasHistory() </strong> <br/> | |
729 | set/get knowledge whether the likely shower history of an event | |
730 | has been traced. | |
731 | ||
732 | ||
733 | <a name="method54"></a> | |
734 | <p/><strong>void Info::zNowISR(bool zNowIn) </strong> <br/> | |
735 | ||
736 | <strong>double Info::zNowISR() </strong> <br/> | |
737 | set/get value of <i>z</i> in latest ISR branching. | |
738 | ||
739 | ||
740 | <a name="method55"></a> | |
741 | <p/><strong>void Info::pT2NowISR(bool pT2NowIn) </strong> <br/> | |
742 | ||
743 | <strong>double Info::pT2NowISR() </strong> <br/> | |
744 | set/get value of <i>pT^2</i> in latest ISR branching. | |
745 | ||
746 | ||
747 | <h3>Header information</h3> | |
748 | ||
749 | A simple string key/value store, mainly intended for accessing | |
750 | information that is stored in the header block of Les Houches Event | |
751 | (LHE) files. In principle, any <code>LHAup</code> derived class can set | |
752 | this header information, which can then be read out later. Although the | |
753 | naming convention is arbitrary, in practice, it is dictated by the | |
754 | XML-like format of LHE files, see <?php $filepath = $_GET["filepath"]; | |
755 | echo "<a href='LesHouchesAccord.php?filepath=".$filepath."' target='page'>";?> | |
756 | Les Houches Accord</a> for more details. | |
757 | ||
758 | <a name="method56"></a> | |
759 | <p/><strong>string Info::header(string key) </strong> <br/> | |
760 | return the header named <code>key</code> | |
761 | ||
762 | ||
763 | <a name="method57"></a> | |
764 | <p/><strong>vector <string> Info::headerKeys() </strong> <br/> | |
765 | return a vector of all header key names | |
766 | ||
767 | ||
768 | <a name="method58"></a> | |
769 | <p/><strong>void Info::setHeader(string key, string val) </strong> <br/> | |
770 | set the header named <code>key</code> with the contents of <code>val</code> | |
771 | ||
772 | ||
773 | </body> | |
774 | </html> | |
775 | ||
776 | <!-- Copyright (C) 2013 Torbjorn Sjostrand --> |