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SUSYProcesses.php @ 1

Last change on this file since 1 was 1, checked in by zerwas, 11 years ago
first import of structure, PYTHIA8 and DELPHES
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1	<html>
2	<head>
3	<title>SUSY Processes</title>
4	<link rel="stylesheet" type="text/css" href="pythia.css"/>
5	<link rel="shortcut icon" href="pythia32.gif"/>
6	</head>
7	<body>
8
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19	<?php
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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='SUSYProcesses.php'>
29
30	<h2>SUSY</h2>
31	<p>
32	Here is collected processes involving supersymmetric particle
33	production, with the exception of the (extended) Higgs sector.
34	Since the number of separate but closely related processes is so big,
35	there will not be switches for each separate process but only for a
36	reasonable set of subgroups. However, the general
37	switches <code>SUSY:idA</code> and <code>SUSY:idB</code> may be used in
38	conjunction with any of these groups to provide some additional
39	flexibility to concentrate on processes involving only specific (s)particle
40	final states, see below.
41	</p>
42
43	<p>
44	Most of the SUSY implementation in PYTHIA 8 has been written by
45	N. Desai, in combination with an MCnet studentship at CERN in
46	2010, with further work having been carried out during 2011.
47	The implementation is documented in [<a href="Bibliography.php" target="page">Des11</a>]. Please give due
48	credit to external contributions to PYTHIA 8, such as this one, by
49	including the original work in your list of references when using this
50	implementation.
51	</p>
52
53	<p>Since the implementation of SUSY processes was only recently
54	completed [<a href="Bibliography.php" target="page">Des11</a>], case-by-case validations against other codes
55	are still recommended. In all cases, a set of default validations have
56	already been carried out by the authors. These validations compared to
57	the PYTHIA 6 SUSY implementation, using an sps1a spectrum. Most of the
58	SLHA2-specific extensions have not been explicitly validated,
59	however, with the exception of the R-parity violating single-sparticle
60	production cross sections.
61	</p>
62
63	<br/><b>Important Note on SLHA:</b>
64	In order to simulate SUSY processes it is required to read in the
65	couplings and masses relevant for the scenario to be studied. This
66	is done with the help of the SUSY Les Houches Accord (SLHA), including
67	the SLHA2 extensions and generalizations. (Internally, the SLHA2
68	conventions are used. SLHA1 spectra are automatically translated into
69	SLHA2 notation during initialization.) The
70	reading of a relevant SLHA file <b>must</b> be set up, as described
71	on <?php $filepath = $_GET["filepath"];
72	echo "<a href='SUSYLesHouchesAccord.php?filepath=".$filepath."' target='page'>";?>the SLHA page</a>.
73	Attempting to generate SUSY processes without a properly initialized
74	SLHA spectrum is strongly discouraged and may lead to unexpected
75	results. Always check for warnings and errors reported by the SLHA
76	reader during the initialization stage.
77
78	<h3>SUSY Processes</h3>
79
80	<br/><b>Note 1:</b> Decays of SUSY particles are described
81	separately <a href="#decays">below</a>.
82
83	<br/><b>Note 2:</b> One special possibility is that the gluino or
84	some squark(s) are sufficiently long-lived to hadronize. See
85	<?php $filepath = $_GET["filepath"];
86	echo "<a href='RHadrons.php?filepath=".$filepath."' target='page'>";?>the R-hadrons page</a> for further details.
87
88	<br/><b>Note 3:</b> lepton- and photon-initial states are not yet available.
89	Only quark/gluon-initiated <i>2 -> 2</i> and <i>2 -> 1</i> (RPV)
90	processes have been implemented. Likewise, direct slepton production
91	has not yet been implemented (i.e., <i>2 -> 2</i> processes
92	involving sleptons in the final state). Sleptons will of course still be
93	produced through cascade decays of heavier (s)particles.
94
95	<br/><b>Note 4:</b> cross sections will be correctly folded with open
96	branching fractions of cascade decays, but at present any difference between
97	particle and antiparticle decay tables is not taken into account. This
98	possibility will be included in a future update.
99
100	<br/><br/><strong>SUSY:all</strong> <input type="radio" name="1" value="on"><strong>On</strong>
101	<input type="radio" name="1" value="off" checked="checked"><strong>Off</strong>
102	(<code>default = <strong>off</strong></code>)<br/>
103	Common switch for production of supersymmetric particles, i.e.
104	particles with R-parity -1.
105
106
107	<br/><br/><table><tr><td><strong>SUSY:idA </td><td></td><td> <input type="text" name="2" value="0" size="20"/>   (<code>default = <strong>0</strong></code>; <code>minimum = 0</code>)</td></tr></table>
108	Option to limit the sum over possible outgoing states in SUSY
109	<i>2 -> 2</i> processes to ones including a specific particle
110	identity code. The default corresponds to summing over all possible
111	indices. A non-zero value of <code>SUSY:idA</code> selects only processes
112	that contain the state corresponding to that particular particle identity
113	code in the fundamental <i>2 -> 2</i> scattering process (symmetrized
114	over particle/antiparticle). It is the user's responsibility to ensure
115	that (a subset of) the processes be to simulated actually include this
116	particle at the <i>2 -> 2</i> level; thus, asking for the lightest
117	neutralino (code 1000021) to be present in a squark-squark production
118	process will give no match.
119
120
121	<br/><br/><table><tr><td><strong>SUSY:idB </td><td></td><td> <input type="text" name="3" value="0" size="20"/>   (<code>default = <strong>0</strong></code>; <code>minimum = 0</code>)</td></tr></table>
122	As for <code>SUSY:idA</code>, but requires an additional particle
123	with PDG code <code>SUSY:idB</code> to be present in the <i>2 -> 2</i>
124	process. Thus, using <code>SUSY:idA</code> and <code>SUSY:idB</code>
125	a specific subprocess can be selected. Again only the absolute sign is
126	used, i.e. the summation over particle and antiparticle is retained.
127
128
129	<br/><br/><table><tr><td><strong>SUSY:sin2thetaWMode </td><td>   (<code>default = <strong>2</strong></code>; <code>minimum = 1</code>; <code>maximum = 3</code>)</td></tr></table>
130	The value of <ei>sin2(thetaW)</ei> should be taken from
131	<br/>
132	<input type="radio" name="4" value="1"><strong>1 </strong>: SM value, defined at <ei>M_Z</ei>, taken from PYTHIA's <code>StandardModel:sin2thetaW</code> parameter.<br/>
133	<input type="radio" name="4" value="2" checked="checked"><strong>2 </strong>: SUSY value, defined at <ei>M_SUSY</ei>, derived from the running gauge couplings in <code>BLOCK GAUGE</code> in the SLHA file. Note: if no such block is present in the input file, this option will default back to option 1 above, i.e., the SM value.<br/>
134	<input type="radio" name="4" value="3"><strong>3 </strong>: Pole value, defined by <ei>1 - M_W^2/M_Z^2</ei>, using the pole masses stored in the SLHA <code>BLOCK MASS</code>, or, alternatively, PYTHIA's internal pole masses if no such block is present.<br/>
135
136	<h4>Gluino Pair Production</h4>
137
138	<br/><br/><strong>SUSY:gg2gluinogluino</strong> <input type="radio" name="5" value="on"><strong>On</strong>
139	<input type="radio" name="5" value="off" checked="checked"><strong>Off</strong>
140	(<code>default = <strong>off</strong></code>)<br/>
141	Pair production of gluinos by gluon-gluon initial states.
142
143
144	<br/><br/><strong>SUSY:qqbar2gluinogluino</strong> <input type="radio" name="6" value="on"><strong>On</strong>
145	<input type="radio" name="6" value="off" checked="checked"><strong>Off</strong>
146	(<code>default = <strong>off</strong></code>)<br/>
147	Pair production of gluinos by quark-antiquark annihilation and
148	<i>t</i>-channel squark exchange. So far, these cross sections assume the
149	squark CKM is aligned with the quark CKM and that all quantities are
150	real, so effects of non-minimal flavour violation and/or CP violation
151	are not yet included.
152
153
154	<h4>Associated Squark-Gluino Production</h4>
155
156	<br/><br/><strong>SUSY:qg2squarkgluino</strong> <input type="radio" name="7" value="on"><strong>On</strong>
157	<input type="radio" name="7" value="off" checked="checked"><strong>Off</strong>
158	(<code>default = <strong>off</strong></code>)<br/>
159	Associated production of a squark with a gluino. Only implemented for the
160	flavor-diagonal case. So far, these cross sections assume the
161	squark CKM is aligned with the quark CKM and that all quantities are
162	real, so effects of non-minimal flavour violation and/or CP violation
163	are not yet included.
164
165
166	<h4>Squark Pair Production</h4>
167
168	<br/><br/><strong>SUSY:gg2squarkantisquark</strong> <input type="radio" name="8" value="on"><strong>On</strong>
169	<input type="radio" name="8" value="off" checked="checked"><strong>Off</strong>
170	(<code>default = <strong>off</strong></code>)<br/>
171	Pair production of a scalar quark together with a scalar antiquark by
172	gluon annhilation via <i>s</i>-channel gluon exhange, <i>t</i>- and
173	<i>u</i>-channel squark exchange, and the direct 4-point coupling.
174	The cross section expression follows [<a href="Bibliography.php" target="page">Boz07</a>].
175	Validation of the FLV and CPV cases has not yet been completed.
176
177
178	<br/><br/><strong>SUSY:qqbar2squarkantisquark</strong> <input type="radio" name="9" value="on"><strong>On</strong>
179	<input type="radio" name="9" value="off" checked="checked"><strong>Off</strong>
180	(<code>default = <strong>off</strong></code>)<br/>
181	Pair production of a scalar quark together with a scalar antiquark
182	by quark-antiquark annihilation.
183	For same-isospin <i>~q~q</i> production (i.e., <i>~u~u</i>,
184	<i>~u~c*</i>, ...), the <i>s</i>-channel gluon, photon, and
185	<i>Z</i> and <i>t</i>-channel gluino contributions have so far
186	been implemented (i.e., the <i>t</i>-channel neutralino contributions
187	are neglected). For opposite-isospin <i>~q~q*</i> production
188	(<i>~u~d</i>, <i>~u~s</i>, ...), the <i>s</i>-channel <i>W</i>
189	and <i>t</i>-channel gluino contributions have been implemented
190	(i.e., the <i>t</i>-channel neutralino contributions are neglected).
191	The cross section expressions follow [<a href="Bibliography.php" target="page">Boz07</a>].
192	Validation of the FLV and CPV cases has not yet been completed.
193	(Note to PYTHIA 6 users:
194	in older PYTHIA 6 versions, a bug caused the <i>~t1~t2*</i> cross to be
195	overcounted by a factor of 2. Starting from version 6.4.24, that
196	generator now agrees with the implementation here.)
197
198
199	<br/><br/><strong>SUSY:qqbar2squarkantisquark:onlyQCD</strong> <input type="radio" name="10" value="on"><strong>On</strong>
200	<input type="radio" name="10" value="off" checked="checked"><strong>Off</strong>
201	(<code>default = <strong>off</strong></code>)<br/>
202	When switched <code>on</code> this flag switches off all but the
203	<i>s</i>-channel gluon contribution in the
204	calculation of same-isospin squark-antisquark production cross
205	sections. Intended for reference only. For the most
206	accurate physics simulation, leave this flag in the <code>off</code>
207	position.
208
209
210	<br/><br/><strong>SUSY:qq2squarksquark</strong> <input type="radio" name="11" value="on"><strong>On</strong>
211	<input type="radio" name="11" value="off" checked="checked"><strong>Off</strong>
212	(<code>default = <strong>off</strong></code>)<br/>
213	Pair production of scalar quarks (squark-squark and its charge
214	conjugate process; for squark-antisquark production see above)
215	by <i>t</i>- and <i>u</i>-channel gluino, neutralino, and
216	chargino exchange. The cross section expressions follow [<a href="Bibliography.php" target="page">Boz07</a>].
217	Validation of the FLV and CPV cases has not yet been completed.
218	(Note to PYTHIA 6 users: PYTHIA 6 only included the gluino exchange
219	contribution, which typically dominates due to the size of the strong
220	coupling; for counterchecks,
221	the flag <code>SUSY:qq2squarksquark:onlyQCD</code>
222	below can be switched on to eliminate the chargino and neutralino
223	contributions.)
224
225
226	<br/><br/><strong>SUSY:qq2squarksquark:onlyQCD</strong> <input type="radio" name="12" value="on"><strong>On</strong>
227	<input type="radio" name="12" value="off" checked="checked"><strong>Off</strong>
228	(<code>default = <strong>off</strong></code>)<br/>
229	When switched <code>on</code> this flag causes the <i>t</i>- or
230	<i>u</i>-channel neutralino and chargino contributions to be
231	ignored in the calculation of squark pair production cross sections.
232	Intended for reference only. For the most accurate physics simulation,
233	leave this flag in the <code>off</code> position.
234
235
236	<h4>Neutralino and Chargino Pair Production</h4>
237
238	<br/><br/><strong>SUSY:qqbar2chi0chi0</strong> <input type="radio" name="13" value="on"><strong>On</strong>
239	<input type="radio" name="13" value="off" checked="checked"><strong>Off</strong>
240	(<code>default = <strong>off</strong></code>)<br/>
241	Pair production of neutralinos by quark-antiquark annihilation. With
242	four neutralino species this gives ten separate processes, codes
243	1201 - 1210. The cross section expressions follow [<a href="Bibliography.php" target="page">Boz07</a>].
244	Validation of the FLV and CPV cases has not yet been completed.
245
246
247	<br/><br/><strong>SUSY:qqbar2chi+-chi0</strong> <input type="radio" name="14" value="on"><strong>On</strong>
248	<input type="radio" name="14" value="off" checked="checked"><strong>Off</strong>
249	(<code>default = <strong>off</strong></code>)<br/>
250	Associated chargino-neutralino production by quark-antiquark
251	annihilation. With four neutralino species, two chargino ones, and
252	maintaining charge conjugate proceeses separate, this gives 16
253	separate processes, codes 1221 - 1236. The cross section expressions
254	follow [<a href="Bibliography.php" target="page">Boz07</a>].
255	Validation of the FLV and CPV cases has not yet been completed.
256
257
258	<br/><br/><strong>SUSY:qqbar2chi+chi-</strong> <input type="radio" name="15" value="on"><strong>On</strong>
259	<input type="radio" name="15" value="off" checked="checked"><strong>Off</strong>
260	(<code>default = <strong>off</strong></code>)<br/>
261	Pair production of charginos by quark-antiquark annihilation. With
262	two chargino species and maintaining mutually charge conjugate
263	processes separate, this gives four separate processes, codes
264	1241 - 1244. The cross section expressions follow [<a href="Bibliography.php" target="page">Boz07</a>].
265	Validation of the FLV and CPV cases has not yet been completed.
266
267
268	<h4>Associated Neutralino/Chargino + Squark/Gluino Production</h4>
269
270	<br/><br/><strong>SUSY:qg2chi0squark</strong> <input type="radio" name="16" value="on"><strong>On</strong>
271	<input type="radio" name="16" value="off" checked="checked"><strong>Off</strong>
272	(<code>default = <strong>off</strong></code>)<br/>
273	Pair production of neutralinos from quark-gluon initial states.
274	The cross section expressions follow [<a href="Bibliography.php" target="page">Boz07</a>].
275	Validation of the FLV and CPV cases has not yet been completed.
276
277
278	<br/><br/><strong>SUSY:qg2chi+-squark</strong> <input type="radio" name="17" value="on"><strong>On</strong>
279	<input type="radio" name="17" value="off" checked="checked"><strong>Off</strong>
280	(<code>default = <strong>off</strong></code>)<br/>
281	Associated chargino-squark production from quark-gluon initial states.
282	annihilation. The cross section expressions
283	follow [<a href="Bibliography.php" target="page">Boz07</a>].
284	Validation of the FLV and CPV cases has not yet been completed.
285
286
287	<br/><br/><strong>SUSY:qqbar2chi0gluino</strong> <input type="radio" name="18" value="on"><strong>On</strong>
288	<input type="radio" name="18" value="off" checked="checked"><strong>Off</strong>
289	(<code>default = <strong>off</strong></code>)<br/>
290	Associated neutralino-gluino production by quark-antiquark
291	annihilation. Status: not implemented yet.
292
293
294	<br/><br/><strong>SUSY:qqbar2chi+-gluino</strong> <input type="radio" name="19" value="on"><strong>On</strong>
295	<input type="radio" name="19" value="off" checked="checked"><strong>Off</strong>
296	(<code>default = <strong>off</strong></code>)<br/>
297	Associated chargino-gluino production by quark-antiquark
298	annihilation. Status: not implemented yet.
299
300
301	<h4>Slepton Production</h4>
302
303	No 2->2 slepton pair production or associated slepton production
304	cross sections have been implemented yet.
305
306	<h4>R-parity violating squark production</h4>
307
308	<br/><br/><strong>SUSY:qq2antisquark</strong> <input type="radio" name="20" value="on"><strong>On</strong>
309	<input type="radio" name="20" value="off" checked="checked"><strong>Off</strong>
310	(<code>default = <strong>off</strong></code>)<br/>
311	Resonant squark production via R-parity violating UDD couplings. The
312	couplings must be input using the SLHA2 structure.
313
314
315	<a name="decays"></a>
316	<h3>Decays of SUSY Particles</h3>
317
318	Based on the parameters read in from the SLHA, PYTHIA 8 will normally
319	compute the decay modes of SUSY particles automatically, using the
320	<code>SusyResonanceDecays</code> class(es). Essentially all tree-level
321	2-body decays in the MSSM
322	have been implemented this way, excepting so far only those involving
323	Higgs bosons (either in the in- or out-state) or gravitinos.
324	Available channels so far include:
325	<ul>
326	<li>~q → q + ~chi</li>
327	<li>~q → ~q + W/Z</li>
328	<li>~q → q + q (RPV UDD)</li>
329	<li>~q → l + q (RPV LQD)</li>
330	<li>~g → ~q + q</li>
331	<li>~chi → ~chi + Z/W</li>
332	<li>~chi → ~q + q</li>
333	<li>~chi → ~l/~nu + l/nu</li>
334	<li>~chi0 → q + q + q (RPV UDD)</li>
335	<li>~l/~nu → l/nu + ~chi</li>
336	<li>~l/~nu → ~l/~nu + W/Z</li>
337	</ul>
338	All channels are still undergoing validation, so this
339	implementation should be considered preliminary.
340	Still missing but to be included in a forthcoming update
341	are: 3-body decays of charginos (via RPV), and 2-body decays of squarks and
342	gauginos with Higgs as one of the decay products.
343
344	<input type="hidden" name="saved" value="1"/>
345
346	<?php
347	echo "<input type='hidden' name='filepath' value='".$_GET["filepath"]."'/>"?>
348
349	<table width="100%"><tr><td align="right"><input type="submit" value="Save Settings" /></td></tr></table>
350	</form>
351
352	<?php
353
354	if($_POST["saved"] == 1)
355	{
356	$filepath = $_POST["filepath"];
357	$handle = fopen($filepath, 'a');
358
359	if($_POST["1"] != "off")
360	{
361	$data = "SUSY:all = ".$_POST["1"]."\n";
362	fwrite($handle,$data);
363	}
364	if($_POST["2"] != "0")
365	{
366	$data = "SUSY:idA = ".$_POST["2"]."\n";
367	fwrite($handle,$data);
368	}
369	if($_POST["3"] != "0")
370	{
371	$data = "SUSY:idB = ".$_POST["3"]."\n";
372	fwrite($handle,$data);
373	}
374	if($_POST["4"] != "2")
375	{
376	$data = "SUSY:sin2thetaWMode = ".$_POST["4"]."\n";
377	fwrite($handle,$data);
378	}
379	if($_POST["5"] != "off")
380	{
381	$data = "SUSY:gg2gluinogluino = ".$_POST["5"]."\n";
382	fwrite($handle,$data);
383	}
384	if($_POST["6"] != "off")
385	{
386	$data = "SUSY:qqbar2gluinogluino = ".$_POST["6"]."\n";
387	fwrite($handle,$data);
388	}
389	if($_POST["7"] != "off")
390	{
391	$data = "SUSY:qg2squarkgluino = ".$_POST["7"]."\n";
392	fwrite($handle,$data);
393	}
394	if($_POST["8"] != "off")
395	{
396	$data = "SUSY:gg2squarkantisquark = ".$_POST["8"]."\n";
397	fwrite($handle,$data);
398	}
399	if($_POST["9"] != "off")
400	{
401	$data = "SUSY:qqbar2squarkantisquark = ".$_POST["9"]."\n";
402	fwrite($handle,$data);
403	}
404	if($_POST["10"] != "off")
405	{
406	$data = "SUSY:qqbar2squarkantisquark:onlyQCD = ".$_POST["10"]."\n";
407	fwrite($handle,$data);
408	}
409	if($_POST["11"] != "off")
410	{
411	$data = "SUSY:qq2squarksquark = ".$_POST["11"]."\n";
412	fwrite($handle,$data);
413	}
414	if($_POST["12"] != "off")
415	{
416	$data = "SUSY:qq2squarksquark:onlyQCD = ".$_POST["12"]."\n";
417	fwrite($handle,$data);
418	}
419	if($_POST["13"] != "off")
420	{
421	$data = "SUSY:qqbar2chi0chi0 = ".$_POST["13"]."\n";
422	fwrite($handle,$data);
423	}
424	if($_POST["14"] != "off")
425	{
426	$data = "SUSY:qqbar2chi+-chi0 = ".$_POST["14"]."\n";
427	fwrite($handle,$data);
428	}
429	if($_POST["15"] != "off")
430	{
431	$data = "SUSY:qqbar2chi+chi- = ".$_POST["15"]."\n";
432	fwrite($handle,$data);
433	}
434	if($_POST["16"] != "off")
435	{
436	$data = "SUSY:qg2chi0squark = ".$_POST["16"]."\n";
437	fwrite($handle,$data);
438	}
439	if($_POST["17"] != "off")
440	{
441	$data = "SUSY:qg2chi+-squark = ".$_POST["17"]."\n";
442	fwrite($handle,$data);
443	}
444	if($_POST["18"] != "off")
445	{
446	$data = "SUSY:qqbar2chi0gluino = ".$_POST["18"]."\n";
447	fwrite($handle,$data);
448	}
449	if($_POST["19"] != "off")
450	{
451	$data = "SUSY:qqbar2chi+-gluino = ".$_POST["19"]."\n";
452	fwrite($handle,$data);
453	}
454	if($_POST["20"] != "off")
455	{
456	$data = "SUSY:qq2antisquark = ".$_POST["20"]."\n";
457	fwrite($handle,$data);
458	}
459	fclose($handle);
460	}
461
462	?>
463	</body>
464	</html>
465
466	<!-- Copyright (C) 2012 Torbjorn Sjostrand -->
467

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