3 <title>Diffraction</title>
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34 Diffraction is not well understood, and several alternative approaches
35 have been proposed. Here we follow a fairly conventional Pomeron-based
36 one, in the Ingelman-Schlein spirit [<a href="Bibliography.php" target="page">Ing85</a>],
37 but integrated to make full use of the standard PYTHIA machinery
38 for multiparton interactions, parton showers and hadronization
39 [<a href="Bibliography.php" target="page">Nav10,Cor10a</a>]. This is the approach pioneered in the PomPyt
40 program by Ingelman and collaborators [<a href="Bibliography.php" target="page">Ing97</a>].
43 For ease of use (and of modelling), the Pomeron-specific parts of the
44 generation are subdivided into three sets of parameters that are rather
45 independent of each other:
46 <br/>(i) the total, elastic and diffractive cross sections are
47 parametrized as functions of the CM energy, or can be set by the user
48 to the desired values, see the
49 <?php $filepath = $_GET["filepath"];
50 echo "<a href='TotalCrossSections.php?filepath=".$filepath."' target='page'>";?>Total Cross Sections</a> page;
51 <br/>(ii) once it has been decided to have a diffractive process,
52 a Pomeron flux parametrization is used to pick the mass of the
53 diffractive system(s) and the <i>t</i> of the exchanged Pomeron,
55 <br/>(iii) a diffractive system of a given mass is classified either
56 as low-mass unresolved, which gives a simple low-<i>pT</i> string
57 topology, or as high-mass resolved, for which the full machinery of
58 multiparton interactions and parton showers are applied, making use of
59 <?php $filepath = $_GET["filepath"];
60 echo "<a href='PDFSelection.php?filepath=".$filepath."' target='page'>";?>Pomeron PDFs</a>.
61 <br/>The parameters related to multiparton interactions, parton showers
62 and hadronization are kept the same as for normal nondiffractive events,
63 with only one exception. This may be questioned, especially for the
64 multiparton interactions, but we do not believe that there are currently
65 enough good diffractive data that would allow detailed separate tunes.
68 The above subdivision may not represent the way "physics comes about".
69 For instance, the total diffractive cross section can be viewed as a
70 convolution of a Pomeron flux with a Pomeron-proton total cross section.
71 Since neither of the two is known from first principles there will be
72 a significant amount of ambiguity in the flux factor. The picture is
73 further complicated by the fact that the possibility of simultaneous
74 further multiparton interactions ("cut Pomerons") will screen the rate of
75 diffractive systems. In the end, our set of parameters refers to the
76 effective description that emerges out of these effects, rather than
77 to the underlying "bare" parameters.
80 In the event record the diffractive system in the case of an excited
81 proton is denoted <code>p_diffr</code>, code 9902210, whereas
82 a central diffractive system is denoted <code>rho_diffr</code>,
83 code 9900110. Apart from representing the correct charge and baryon
84 numbers, no deeper meaning should be attributed to the names.
88 As already mentioned above, the total diffractive cross section is fixed
89 by a default energy-dependent parametrization or by the user, see the
90 <?php $filepath = $_GET["filepath"];
91 echo "<a href='TotalCrossSections.php?filepath=".$filepath."' target='page'>";?>Total Cross Sections</a> page.
92 Therefore we do not attribute any significance to the absolute
93 normalization of the Pomeron flux. The choice of Pomeron flux model
94 still will decide on the mass spectrum of diffractive states and the
95 <i>t</i> spectrum of the Pomeron exchange.
97 <br/><br/><table><tr><td><strong>Diffraction:PomFlux </td><td> (<code>default = <strong>1</strong></code>; <code>minimum = 1</code>; <code>maximum = 5</code>)</td></tr></table>
98 Parametrization of the Pomeron flux <ei>f_Pom/p( x_Pom, t)</ei>.
100 <input type="radio" name="1" value="1" checked="checked"><strong>1 </strong>: Schuler and Sjöstrand <ref>Sch94</ref>: based on a critical Pomeron, giving a mass spectrum roughly like <ei>dm^2/m^2</ei>; a mass-dependent exponential <ei>t</ei> slope that reduces the rate of low-mass states; partly compensated by a very-low-mass (resonance region) enhancement. Is currently the only one that contains a separate <ei>t</ei> spectrum for double diffraction (along with MBR) and separate parameters for pion beams.<br/>
101 <input type="radio" name="1" value="2"><strong>2 </strong>: Bruni and Ingelman <ref>Bru93</ref>: also a critical Pomeron giving close to <ei>dm^2/m^2</ei>, with a <ei>t</ei> distribution the sum of two exponentials. The original model only covers single diffraction, but is here expanded by analogy to double and central diffraction.<br/>
102 <input type="radio" name="1" value="3"><strong>3 </strong>: a conventional Pomeron description, in the RapGap manual <ref>Jun95</ref> attributed to Berger et al. and Streng <ref>Ber87a</ref>, but there (and here) with values updated to a supercritical Pomeron with <ei>epsilon > 0</ei> (see below), which gives a stronger peaking towards low-mass diffractive states, and with a mass-dependent (the <ei>alpha'</ei> below) exponential <ei>t</ei> slope. The original model only covers single diffraction, but is here expanded by analogy to double and central diffraction. <br/>
103 <input type="radio" name="1" value="4"><strong>4 </strong>: a conventional Pomeron description, attributed to Donnachie and Landshoff <ref>Don84</ref>, again with supercritical Pomeron, with the same two parameters as option 3 above, but this time with a power-law <ei>t</ei> distribution. The original model only covers single diffraction, but is here expanded by analogy to double and central diffraction.<br/>
104 <input type="radio" name="1" value="5"><strong>5 </strong>: the MBR (Minimum Bias Rockefeller) simulation of (anti)proton-proton interactions <ref>Cie12</ref>. The event generation follows a renormalized-Regge-theory model, sucessfully tested using CDF data. The simulation includes single and double diffraction, as well as the central diffractive (double-Pomeron exchange) process (106). Only <ei>p p</ei>, <ei>pbar p</ei> and <ei>p pbar</ei> beam combinations are allowed for this option. Several parameters of this model are listed below. <br/>
107 In options 3 and 4 above, the Pomeron Regge trajectory is
110 alpha(t) = 1 + epsilon + alpha' t
112 The <i>epsilon</i> and <i>alpha'</i> parameters can be set
115 <br/><br/><table><tr><td><strong>Diffraction:PomFluxEpsilon </td><td></td><td> <input type="text" name="2" value="0.085" size="20"/> (<code>default = <strong>0.085</strong></code>; <code>minimum = 0.02</code>; <code>maximum = 0.15</code>)</td></tr></table>
116 The Pomeron trajectory intercept <i>epsilon</i> above. For technical
117 reasons <i>epsilon > 0</i> is necessary in the current implementation.
119 <br/><br/><table><tr><td><strong>Diffraction:PomFluxAlphaPrime </td><td></td><td> <input type="text" name="3" value="0.25" size="20"/> (<code>default = <strong>0.25</strong></code>; <code>minimum = 0.1</code>; <code>maximum = 0.4</code>)</td></tr></table>
120 The Pomeron trajectory slope <i>alpha'</i> above.
123 When option 5 is selected, the following parameters of the MBR model
124 [<a href="Bibliography.php" target="page">Cie12</a>] are used:
126 <br/><br/><table><tr><td><strong>Diffraction:MBRepsilon </td><td></td><td> <input type="text" name="4" value="0.104" size="20"/> (<code>default = <strong>0.104</strong></code>; <code>minimum = 0.02</code>; <code>maximum = 0.15</code>)</td></tr></table>
127 <br/><br/><table><tr><td><strong>Diffraction:MBRalpha </td><td></td><td> <input type="text" name="5" value="0.25" size="20"/> (<code>default = <strong>0.25</strong></code>; <code>minimum = 0.1</code>; <code>maximum = 0.4</code>)</td></tr></table>
128 the parameters of the Pomeron trajectory.
130 <br/><br/><table><tr><td><strong>Diffraction:MBRbeta0 </td><td></td><td> <input type="text" name="6" value="6.566" size="20"/> (<code>default = <strong>6.566</strong></code>; <code>minimum = 0.0</code>; <code>maximum = 10.0</code>)</td></tr></table>
131 <br/><br/><table><tr><td><strong>Diffraction:MBRsigma0 </td><td></td><td> <input type="text" name="7" value="2.82" size="20"/> (<code>default = <strong>2.82</strong></code>; <code>minimum = 0.0</code>; <code>maximum = 5.0</code>)</td></tr></table>
132 the Pomeron-proton coupling, and the total Pomeron-proton cross section.
134 <br/><br/><table><tr><td><strong>Diffraction:MBRm2Min </td><td></td><td> <input type="text" name="8" value="1.5" size="20"/> (<code>default = <strong>1.5</strong></code>; <code>minimum = 0.0</code>; <code>maximum = 3.0</code>)</td></tr></table>
135 the lowest value of the mass squared of the dissociated system.
137 <br/><br/><table><tr><td><strong>Diffraction:MBRdyminSDflux </td><td></td><td> <input type="text" name="9" value="2.3" size="20"/> (<code>default = <strong>2.3</strong></code>; <code>minimum = 0.0</code>; <code>maximum = 5.0</code>)</td></tr></table>
138 <br/><br/><table><tr><td><strong>Diffraction:MBRdyminDDflux </td><td></td><td> <input type="text" name="10" value="2.3" size="20"/> (<code>default = <strong>2.3</strong></code>; <code>minimum = 0.0</code>; <code>maximum = 5.0</code>)</td></tr></table>
139 <br/><br/><table><tr><td><strong>Diffraction:MBRdyminCDflux </td><td></td><td> <input type="text" name="11" value="2.3" size="20"/> (<code>default = <strong>2.3</strong></code>; <code>minimum = 0.0</code>; <code>maximum = 5.0</code>)</td></tr></table>
140 the minimum width of the rapidity gap used in the calculation of
141 <i>Ngap(s)</i> (flux renormalization).
143 <br/><br/><table><tr><td><strong>Diffraction:MBRdyminSD </td><td></td><td> <input type="text" name="12" value="2.0" size="20"/> (<code>default = <strong>2.0</strong></code>; <code>minimum = 0.0</code>; <code>maximum = 5.0</code>)</td></tr></table>
144 <br/><br/><table><tr><td><strong>Diffraction:MBRdyminDD </td><td></td><td> <input type="text" name="13" value="2.0" size="20"/> (<code>default = <strong>2.0</strong></code>; <code>minimum = 0.0</code>; <code>maximum = 5.0</code>)</td></tr></table>
145 <br/><br/><table><tr><td><strong>Diffraction:MBRdyminCD </td><td></td><td> <input type="text" name="14" value="2.0" size="20"/> (<code>default = <strong>2.0</strong></code>; <code>minimum = 0.0</code>; <code>maximum = 5.0</code>)</td></tr></table>
146 the minimum width of the rapidity gap used in the calculation of cross
147 sections, i.e. the parameter <i>dy_S</i>, which suppresses the cross
148 section at low <i>dy</i> (non-diffractive region).
150 <br/><br/><table><tr><td><strong>Diffraction:MBRdyminSigSD </td><td></td><td> <input type="text" name="15" value="0.5" size="20"/> (<code>default = <strong>0.5</strong></code>; <code>minimum = 0.001</code>; <code>maximum = 5.0</code>)</td></tr></table>
151 <br/><br/><table><tr><td><strong>Diffraction:MBRdyminSigDD </td><td></td><td> <input type="text" name="16" value="0.5" size="20"/> (<code>default = <strong>0.5</strong></code>; <code>minimum = 0.001</code>; <code>maximum = 5.0</code>)</td></tr></table>
152 <br/><br/><table><tr><td><strong>Diffraction:MBRdyminSigCD </td><td></td><td> <input type="text" name="17" value="0.5" size="20"/> (<code>default = <strong>0.5</strong></code>; <code>minimum = 0.001</code>; <code>maximum = 5.0</code>)</td></tr></table>
153 the parameter <i>sigma_S</i>, used for the cross section suppression at
154 low <i>dy</i> (non-diffractive region).
156 <h3>Separation into low and high masses</h3>
158 Preferably one would want to have a perturbative picture of the
159 dynamics of Pomeron-proton collisions, like multiparton interactions
160 provide for proton-proton ones. However, while PYTHIA by default
161 will only allow collisions with a CM energy above 10 GeV, the
162 mass spectrum of diffractive systems will stretch to down to
163 the order of 1.2 GeV. It would not be feasible to attempt a
164 perturbative description there. Therefore we do offer a simpler
165 low-mass description, with only longitudinally stretched strings,
166 with a gradual switch-over to the perturbative picture for higher
167 masses. The probability for the latter picture is parametrized as
169 P_pert = P_max ( 1 - exp( (m_diffr - m_min) / m_width ) )
171 which vanishes for the diffractive system mass
172 <i>m_diffr < m_min</i>, and is <i>1 - 1/e = 0.632</i> for
173 <i>m_diffr = m_min + m_width</i>, assuming <i>P_max = 1</i>.
175 <br/><br/><table><tr><td><strong>Diffraction:mMinPert </td><td></td><td> <input type="text" name="18" value="10." size="20"/> (<code>default = <strong>10.</strong></code>; <code>minimum = 5.</code>)</td></tr></table>
176 The abovementioned threshold mass <i>m_min</i> for phasing in a
177 perturbative treatment. If you put this parameter to be bigger than
178 the CM energy then there will be no perturbative description at all,
179 but only the older low-<i>pt</i> description.
182 <br/><br/><table><tr><td><strong>Diffraction:mWidthPert </td><td></td><td> <input type="text" name="19" value="10." size="20"/> (<code>default = <strong>10.</strong></code>; <code>minimum = 0.</code>)</td></tr></table>
183 The abovementioned threshold width <i>m_width.</i>
186 <br/><br/><table><tr><td><strong>Diffraction:probMaxPert </td><td></td><td> <input type="text" name="20" value="1." size="20"/> (<code>default = <strong>1.</strong></code>; <code>minimum = 0.</code>; <code>maximum = 1.</code>)</td></tr></table>
187 The abovementioned maximum probability <i>P_max.</i>. Would
188 normally be assumed to be unity, but a somewhat lower value could
189 be used to represent a small nonperturbative component also at
190 high diffractive masses.
193 <h3>Low-mass diffraction</h3>
195 When an incoming hadron beam is diffractively excited, it is modeled
196 as if either a valence quark or a gluon is kicked out from the hadron.
197 In the former case this produces a simple string to the leftover
198 remnant, in the latter it gives a hairpin arrangement where a string
199 is stretched from one quark in the remnant, via the gluon, back to the
200 rest of the remnant. The latter ought to dominate at higher mass of
201 the diffractive system. Therefore an approximate behaviour like
207 <br/><br/><table><tr><td><strong>Diffraction:pickQuarkNorm </td><td></td><td> <input type="text" name="21" value="5.0" size="20"/> (<code>default = <strong>5.0</strong></code>; <code>minimum = 0.</code>)</td></tr></table>
208 The abovementioned normalization <i>N</i> for the relative quark
209 rate in diffractive systems.
212 <br/><br/><table><tr><td><strong>Diffraction:pickQuarkPower </td><td></td><td> <input type="text" name="22" value="1.0" size="20"/> (<code>default = <strong>1.0</strong></code>)</td></tr></table>
213 The abovementioned mass-dependence power <i>p</i> for the relative
214 quark rate in diffractive systems.
218 When a gluon is kicked out from the hadron, the longitudinal momentum
219 sharing between the the two remnant partons is determined by the
220 same parameters as above. It is plausible that the primordial
221 <i>kT</i> may be lower than in perturbative processes, however:
223 <br/><br/><table><tr><td><strong>Diffraction:primKTwidth </td><td></td><td> <input type="text" name="23" value="0.5" size="20"/> (<code>default = <strong>0.5</strong></code>; <code>minimum = 0.</code>)</td></tr></table>
224 The width of Gaussian distributions in <i>p_x</i> and <i>p_y</i>
225 separately that is assigned as a primordial <i>kT</i> to the two
226 beam remnants when a gluon is kicked out of a diffractive system.
229 <br/><br/><table><tr><td><strong>Diffraction:largeMassSuppress </td><td></td><td> <input type="text" name="24" value="2." size="20"/> (<code>default = <strong>2.</strong></code>; <code>minimum = 0.</code>)</td></tr></table>
230 The choice of longitudinal and transverse structure of a diffractive
231 beam remnant for a kicked-out gluon implies a remnant mass
232 <i>m_rem</i> distribution (i.e. quark plus diquark invariant mass
233 for a baryon beam) that knows no bounds. A suppression like
234 <i>(1 - m_rem^2 / m_diff^2)^p</i> is therefore introduced, where
235 <i>p</i> is the <code>diffLargeMassSuppress</code> parameter.
238 <h3>High-mass diffraction</h3>
240 The perturbative description need to use parton densities of the
241 Pomeron. The options are described in the page on
242 <?php $filepath = $_GET["filepath"];
243 echo "<a href='PDFSelection.php?filepath=".$filepath."' target='page'>";?>PDF Selection</a>. The standard
244 perturbative multiparton interactions framework then provides
245 cross sections for parton-parton interactions. In order to
246 turn these cross section into probabilities one also needs an
247 ansatz for the Pomeron-proton total cross section. In the literature
248 one often finds low numbers for this, of the order of 2 mb.
249 These, if taken at face value, would give way too much activity
250 per event. There are ways to tame this, e.g. by a larger <i>pT0</i>
251 than in the normal pp framework. Actually, there are many reasons
252 to use a completely different set of parameters for MPI in
253 diffraction than in pp collisions, especially with respect to the
254 impact-parameter picture, see below. A lower number in some frameworks
255 could alternatively be regarded as a consequence of screening, with
256 a larger "bare" number.
259 For now, however, an attempt at the most general solution would
260 carry too far, and instead we patch up the problem by using a
261 larger Pomeron-proton total cross section, such that average
262 activity makes more sense. This should be viewed as the main
263 tunable parameter in the description of high-mass diffraction.
264 It is to be fitted to diffractive event-shape data such as the average
265 charged multiplicity. It would be very closely tied to the choice of
266 Pomeron PDF; we remind that some of these add up to less than unit
267 momentum sum in the Pomeron, a choice that also affect the value
268 one ends up with. Furthermore, like with hadronic cross sections,
269 it is quite plausible that the Pomeron-proton cross section increases
270 with energy, so we have allowed for a powerlike dependence on the
273 <br/><br/><table><tr><td><strong>Diffraction:sigmaRefPomP </td><td></td><td> <input type="text" name="25" value="10." size="20"/> (<code>default = <strong>10.</strong></code>; <code>minimum = 2.</code>; <code>maximum = 40.</code>)</td></tr></table>
274 The assumed Pomeron-proton effective cross section, as used for
275 multiparton interactions in diffractive systems. If this cross section
276 is made to depend on the mass of the diffractive system then the above
277 value refers to the cross section at the reference scale, and
279 sigma_PomP(m) = sigma_PomP(m_ref) * (m / m_ref)^p
281 where <i>m</i> is the mass of the diffractive system, <i>m_ref</i>
282 is the reference mass scale <code>Diffraction:mRefPomP</code> below and
283 <i>p</i> is the mass-dependence power <code>Diffraction:mPowPomP</code>.
284 Note that a larger cross section value gives less MPI activity per event.
285 There is no point in making the cross section too big, however, since
286 then <i>pT0</i> will be adjusted downwards to ensure that the
287 integrated perturbative cross section stays above this assumed total
288 cross section. (The requirement of at least one perturbative interaction
292 <br/><br/><table><tr><td><strong>Diffraction:mRefPomP </td><td></td><td> <input type="text" name="26" value="100.0" size="20"/> (<code>default = <strong>100.0</strong></code>; <code>minimum = 1.</code>)</td></tr></table>
293 The <i>mRef</i> reference mass scale introduced above.
296 <br/><br/><table><tr><td><strong>Diffraction:mPowPomP </td><td></td><td> <input type="text" name="27" value="0.0" size="20"/> (<code>default = <strong>0.0</strong></code>; <code>minimum = 0.0</code>; <code>maximum = 0.5</code>)</td></tr></table>
297 The <i>p</i> mass rescaling pace introduced above.
301 Also note that, even for a fixed CM energy of events, the diffractive
302 subsystem will range from the abovementioned threshold mass
303 <i>m_min</i> to the full CM energy, with a variation of parameters
304 such as <i>pT0</i> along this mass range. Therefore multiparton
305 interactions are initialized for a few different diffractive masses,
306 currently five, and all relevant parameters are interpolated between
307 them to obtain the behaviour at a specific diffractive mass.
308 Furthermore, <i>A B ->X B</i> and <i>A B ->A X</i> are
309 initialized separately, to allow for different beams or PDF's on the
310 two sides. These two aspects mean that initialization of MPI is
311 appreciably slower when perturbative high-mass diffraction is allowed.
314 Diffraction tends to be peripheral, i.e. occur at intermediate impact
315 parameter for the two protons. That aspect is implicit in the selection
316 of diffractive cross section. For the simulation of the Pomeron-proton
317 subcollision it is the impact-parameter distribution of that particular
318 subsystem that should rather be modelled. That is, it also involves
319 the transverse coordinate space of a Pomeron wavefunction. The outcome
320 of the convolution therefore could be a different shape than for
321 nondiffractive events. For simplicity we allow the same kind of
322 options as for nondiffractive events, except that the
323 <code>bProfile = 4</code> option for now is not implemented.
325 <br/><br/><table><tr><td><strong>Diffraction:bProfile </td><td> (<code>default = <strong>1</strong></code>; <code>minimum = 0</code>; <code>maximum = 3</code>)</td></tr></table>
326 Choice of impact parameter profile for the incoming hadron beams.
328 <input type="radio" name="28" value="0"><strong>0 </strong>: no impact parameter dependence at all.<br/>
329 <input type="radio" name="28" value="1" checked="checked"><strong>1 </strong>: a simple Gaussian matter distribution; no free parameters.<br/>
330 <input type="radio" name="28" value="2"><strong>2 </strong>: a double Gaussian matter distribution, with the two free parameters <ei>coreRadius</ei> and <ei>coreFraction</ei>.<br/>
331 <input type="radio" name="28" value="3"><strong>3 </strong>: an overlap function, i.e. the convolution of the matter distributions of the two incoming hadrons, of the form <ei>exp(- b^expPow)</ei>, where <ei>expPow</ei> is a free parameter.<br/>
333 <br/><br/><table><tr><td><strong>Diffraction:coreRadius </td><td></td><td> <input type="text" name="29" value="0.4" size="20"/> (<code>default = <strong>0.4</strong></code>; <code>minimum = 0.1</code>; <code>maximum = 1.</code>)</td></tr></table>
334 When assuming a double Gaussian matter profile, <i>bProfile = 2</i>,
335 the inner core is assumed to have a radius that is a factor
336 <i>coreRadius</i> smaller than the rest.
339 <br/><br/><table><tr><td><strong>Diffraction:coreFraction </td><td></td><td> <input type="text" name="30" value="0.5" size="20"/> (<code>default = <strong>0.5</strong></code>; <code>minimum = 0.</code>; <code>maximum = 1.</code>)</td></tr></table>
340 When assuming a double Gaussian matter profile, <i>bProfile = 2</i>,
341 the inner core is assumed to have a fraction <i>coreFraction</i>
342 of the matter content of the hadron.
345 <br/><br/><table><tr><td><strong>Diffraction:expPow </td><td></td><td> <input type="text" name="31" value="1." size="20"/> (<code>default = <strong>1.</strong></code>; <code>minimum = 0.4</code>; <code>maximum = 10.</code>)</td></tr></table>
346 When <i>bProfile = 3</i> it gives the power of the assumed overlap
347 shape <i>exp(- b^expPow)</i>. Default corresponds to a simple
348 exponential drop, which is not too dissimilar from the overlap
349 obtained with the standard double Gaussian parameters. For
350 <i>expPow = 2</i> we reduce to the simple Gaussian, <i>bProfile = 1</i>,
351 and for <i>expPow -> infinity</i> to no impact parameter dependence
352 at all, <i>bProfile = 0</i>. For small <i>expPow</i> the program
353 becomes slow and unstable, so the min limit must be respected.
356 <input type="hidden" name="saved" value="1"/>
359 echo "<input type='hidden' name='filepath' value='".$_GET["filepath"]."'/>"?>
361 <table width="100%"><tr><td align="right"><input type="submit" value="Save Settings" /></td></tr></table>
366 if($_POST["saved"] == 1)
368 $filepath = $_POST["filepath"];
369 $handle = fopen($filepath, 'a');
371 if($_POST["1"] != "1")
373 $data = "Diffraction:PomFlux = ".$_POST["1"]."\n";
374 fwrite($handle,$data);
376 if($_POST["2"] != "0.085")
378 $data = "Diffraction:PomFluxEpsilon = ".$_POST["2"]."\n";
379 fwrite($handle,$data);
381 if($_POST["3"] != "0.25")
383 $data = "Diffraction:PomFluxAlphaPrime = ".$_POST["3"]."\n";
384 fwrite($handle,$data);
386 if($_POST["4"] != "0.104")
388 $data = "Diffraction:MBRepsilon = ".$_POST["4"]."\n";
389 fwrite($handle,$data);
391 if($_POST["5"] != "0.25")
393 $data = "Diffraction:MBRalpha = ".$_POST["5"]."\n";
394 fwrite($handle,$data);
396 if($_POST["6"] != "6.566")
398 $data = "Diffraction:MBRbeta0 = ".$_POST["6"]."\n";
399 fwrite($handle,$data);
401 if($_POST["7"] != "2.82")
403 $data = "Diffraction:MBRsigma0 = ".$_POST["7"]."\n";
404 fwrite($handle,$data);
406 if($_POST["8"] != "1.5")
408 $data = "Diffraction:MBRm2Min = ".$_POST["8"]."\n";
409 fwrite($handle,$data);
411 if($_POST["9"] != "2.3")
413 $data = "Diffraction:MBRdyminSDflux = ".$_POST["9"]."\n";
414 fwrite($handle,$data);
416 if($_POST["10"] != "2.3")
418 $data = "Diffraction:MBRdyminDDflux = ".$_POST["10"]."\n";
419 fwrite($handle,$data);
421 if($_POST["11"] != "2.3")
423 $data = "Diffraction:MBRdyminCDflux = ".$_POST["11"]."\n";
424 fwrite($handle,$data);
426 if($_POST["12"] != "2.0")
428 $data = "Diffraction:MBRdyminSD = ".$_POST["12"]."\n";
429 fwrite($handle,$data);
431 if($_POST["13"] != "2.0")
433 $data = "Diffraction:MBRdyminDD = ".$_POST["13"]."\n";
434 fwrite($handle,$data);
436 if($_POST["14"] != "2.0")
438 $data = "Diffraction:MBRdyminCD = ".$_POST["14"]."\n";
439 fwrite($handle,$data);
441 if($_POST["15"] != "0.5")
443 $data = "Diffraction:MBRdyminSigSD = ".$_POST["15"]."\n";
444 fwrite($handle,$data);
446 if($_POST["16"] != "0.5")
448 $data = "Diffraction:MBRdyminSigDD = ".$_POST["16"]."\n";
449 fwrite($handle,$data);
451 if($_POST["17"] != "0.5")
453 $data = "Diffraction:MBRdyminSigCD = ".$_POST["17"]."\n";
454 fwrite($handle,$data);
456 if($_POST["18"] != "10.")
458 $data = "Diffraction:mMinPert = ".$_POST["18"]."\n";
459 fwrite($handle,$data);
461 if($_POST["19"] != "10.")
463 $data = "Diffraction:mWidthPert = ".$_POST["19"]."\n";
464 fwrite($handle,$data);
466 if($_POST["20"] != "1.")
468 $data = "Diffraction:probMaxPert = ".$_POST["20"]."\n";
469 fwrite($handle,$data);
471 if($_POST["21"] != "5.0")
473 $data = "Diffraction:pickQuarkNorm = ".$_POST["21"]."\n";
474 fwrite($handle,$data);
476 if($_POST["22"] != "1.0")
478 $data = "Diffraction:pickQuarkPower = ".$_POST["22"]."\n";
479 fwrite($handle,$data);
481 if($_POST["23"] != "0.5")
483 $data = "Diffraction:primKTwidth = ".$_POST["23"]."\n";
484 fwrite($handle,$data);
486 if($_POST["24"] != "2.")
488 $data = "Diffraction:largeMassSuppress = ".$_POST["24"]."\n";
489 fwrite($handle,$data);
491 if($_POST["25"] != "10.")
493 $data = "Diffraction:sigmaRefPomP = ".$_POST["25"]."\n";
494 fwrite($handle,$data);
496 if($_POST["26"] != "100.0")
498 $data = "Diffraction:mRefPomP = ".$_POST["26"]."\n";
499 fwrite($handle,$data);
501 if($_POST["27"] != "0.0")
503 $data = "Diffraction:mPowPomP = ".$_POST["27"]."\n";
504 fwrite($handle,$data);
506 if($_POST["28"] != "1")
508 $data = "Diffraction:bProfile = ".$_POST["28"]."\n";
509 fwrite($handle,$data);
511 if($_POST["29"] != "0.4")
513 $data = "Diffraction:coreRadius = ".$_POST["29"]."\n";
514 fwrite($handle,$data);
516 if($_POST["30"] != "0.5")
518 $data = "Diffraction:coreFraction = ".$_POST["30"]."\n";
519 fwrite($handle,$data);
521 if($_POST["31"] != "1.")
523 $data = "Diffraction:expPow = ".$_POST["31"]."\n";
524 fwrite($handle,$data);
533 <!-- Copyright (C) 2012 Torbjorn Sjostrand -->