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c6b60c38 | 1 | // main14.cc is a part of the PYTHIA event generator. |
2 | // Copyright (C) 2013 Torbjorn Sjostrand. | |
3 | // PYTHIA is licenced under the GNU GPL version 2, see COPYING for details. | |
4 | // Please respect the MCnet Guidelines, see GUIDELINES for details. | |
5 | ||
6 | // Comparison with some PYTHIA 6.413 cross sections process by process. | |
7 | // Several processes have been left out to keep reasonable execution time. | |
8 | // Some processes are not handled absolutely identically, so minor | |
9 | // systematic differences may occur in addition to the statistical ones. | |
10 | // (For some MSSM Higgs processes 6.413 has been modified to use | |
11 | // running quark masses in loops, like 8.1, to allow proper comparison.) | |
12 | // Subruns 0 - 5 : QCD jets | |
13 | // 6 - 10 : prompt photons. | |
14 | // 11 - 12 : t-channel gamma/Z/W exchange. | |
15 | // 13 - 23 : gamma*/Z^0/W^+-, singly, in pairs or with parton | |
16 | // 24 - 25 : onia. | |
17 | // 26 - 30 : top. | |
18 | // 31 - 40 : Standard Model Higgs. | |
19 | // 41 - 45 : MSSM Higgses (trivial couplings). | |
20 | // 46 - 47 : Z' and W' | |
21 | // 48 - 51 : Left-right-symmetric scenario. | |
22 | // 52 - 52 : Leptoquark. | |
23 | // 53 - 55 : Excited fermions (compositeness). | |
24 | // 56 - 56 : excited Graviton (RS extra dimensions). | |
25 | ||
26 | #include "Pythia.h" | |
27 | ||
28 | using namespace Pythia8; | |
29 | ||
30 | int main() { | |
31 | ||
32 | // First and last process to test: can run from 0 through 40. | |
33 | int iFirst = 0; | |
34 | int iLast = 56; | |
35 | ||
36 | // Statistics. Pythia6 run was with 10000, so no point to use more. | |
37 | int nEvent = 10000; | |
38 | ||
39 | // Normally one subprocess word per subrun, but exceptions exist. | |
40 | int nSub[100]; | |
41 | for (int i = 0; i < 100; ++i) nSub[i] = 1; | |
42 | nSub[1] = 3; | |
43 | nSub[5] = 3; | |
44 | // Starting positions in subprocess words list, recursively defined. | |
45 | int iBeg[101] = { 0 }; | |
46 | for (int i = 0; i < 100; ++i) iBeg[i + 1] = iBeg[i] + nSub[i]; | |
47 | // List of subprocess words. | |
48 | string processes[61] = { "HardQCD:gg2gg", "HardQCD:gg2qqbar", | |
49 | "HardQCD:gg2ccbar", "HardQCD:gg2bbbar","HardQCD:qg2qg" , | |
50 | "HardQCD:qq2qq", "HardQCD:qqbar2gg", "HardQCD:qqbar2qqbarNew", | |
51 | "HardQCD:qqbar2ccbar", "HardQCD:qqbar2bbbar", "PromptPhoton:qg2qgamma", | |
52 | "PromptPhoton:qqbar2ggamma", "PromptPhoton:gg2ggamma", | |
53 | "PromptPhoton:ffbar2gammagamma", "PromptPhoton:gg2gammagamma", | |
54 | "WeakBosonExchange:ff2ff(t:gmZ)", "WeakBosonExchange:ff2ff(t:W)", | |
55 | "WeakSingleBoson:ffbar2gmZ", "WeakSingleBoson:ffbar2W", | |
56 | "WeakDoubleBoson:ffbar2gmZgmZ", "WeakDoubleBoson:ffbar2ZW", | |
57 | "WeakDoubleBoson:ffbar2WW", "WeakBosonAndParton:qqbar2gmZg", | |
58 | "WeakBosonAndParton:qg2gmZq", "WeakBosonAndParton:ffbar2gmZgm", | |
59 | "WeakBosonAndParton:qqbar2Wg", "WeakBosonAndParton:qg2Wq", | |
60 | "WeakBosonAndParton:ffbar2Wgm", "Charmonium:all", "Bottomonium:all", | |
61 | "Top:gg2ttbar", "Top:qqbar2ttbar", "Top:qq2tq(t:W)", | |
62 | "Top:ffbar2ttbar(s:gmZ)", "Top:ffbar2tqbar(s:W)", | |
63 | "HiggsSM:ffbar2H", "HiggsSM:gg2H", "HiggsSM:ffbar2HZ", | |
64 | "HiggsSM:ffbar2HW", "HiggsSM:ff2Hff(t:ZZ)", "HiggsSM:ff2Hff(t:WW)", | |
65 | "HiggsSM:qg2Hq", "HiggsSM:gg2Hg(l:t)", "HiggsSM:qg2Hq(l:t)", | |
66 | "HiggsSM:qqbar2Hg(l:t)", "HiggsBSM:allH1", "HiggsBSM:allH2", | |
67 | "HiggsBSM:allA3", "HiggsBSM:allH+-", "HiggsBSM:allHpair", | |
68 | "NewGaugeBoson:ffbar2gmZZprime", "NewGaugeBoson:ffbar2Wprime", | |
69 | "LeftRightSymmmetry:ffbar2ZR", "LeftRightSymmmetry:ffbar2WR", | |
70 | "LeftRightSymmmetry:ffbar2HLHL", "LeftRightSymmmetry:ffbar2HRHR", | |
71 | "LeptoQuark:all", "ExcitedFermion:dg2dStar", | |
72 | "ExcitedFermion:qq2dStarq", "ExcitedFermion:qqbar2eStare", | |
73 | "ExtraDimensionsG*:all" }; | |
74 | ||
75 | // List of cross sections from Pythia6. | |
76 | double sigma6[57] = { 4.960e-01, 1.627e-02, 2.790e-01, 2.800e-02, | |
77 | 3.310e-04, 3.653e-04, 1.697e-04, 1.163e-05, 1.065e-07, 8.259e-08, | |
78 | 8.237e-08, 2.544e-05, 5.321e-06, 5.571e-05, 1.621e-04, 9.039e-09, | |
79 | 2.247e-08, 5.893e-08, 3.781e-06, 1.078e-05, 4.551e-08, 1.025e-05, | |
80 | 3.208e-05, 5.435e-08, 1.038e-04, 3.929e-05, 4.155e-07, 6.685e-08, | |
81 | 1.898e-07, 4.240e-10, 7.142e-09, 1.547e-10, 7.064e-09, 1.316e-10, | |
82 | 2.332e-10, 5.105e-10, 1.316e-09, 4.462e-11, 5.557e-09, 1.966e-09, | |
83 | 8.725e-12, 2.450e-08, 5.839e-09, 1.687e-08, 8.950e-11, 4.188e-11, | |
84 | 1.980e-07, 4.551e-07, 6.005e-09, 1.102e-07, 7.784e-11, 3.488e-11, | |
85 | 6.006e-08, 3.235e-06, 1.689e-05, 5.986e-07, 3.241e-10 }; | |
86 | ||
87 | // Generator. | |
88 | Pythia pythia; | |
89 | ||
90 | // Standard set of masses for comparison with Fortran code. | |
91 | pythia.readString("5:m0 = 4.2"); | |
92 | pythia.readString("6:m0 = 175."); | |
93 | pythia.readString("23:m0 = 91.2"); | |
94 | pythia.readString("24:m0 = 80."); | |
95 | ||
96 | // Same kinematics cuts as Fortran code. | |
97 | pythia.readString("PhaseSpace:pTHatMin = 20."); | |
98 | pythia.readString("6:mMin = 20."); | |
99 | pythia.readString("23:mMin = 20."); | |
100 | pythia.readString("24:mMin = 20."); | |
101 | pythia.readString("25:mMin = 20."); | |
102 | pythia.readString("32:mMin = 400."); | |
103 | pythia.readString("34:mMin = 400."); | |
104 | pythia.readString("42:mMin = 50."); | |
105 | pythia.readString("5000039:mMin = 50."); | |
106 | ||
107 | // Also same renormalization and factorization scale. | |
108 | pythia.readString("SigmaProcess:renormScale2 = 3"); | |
109 | pythia.readString("SigmaProcess:factorScale2 = 3"); | |
110 | ||
111 | // Switch off unnecessary parts. | |
112 | pythia.readString("PartonLevel:all = off"); | |
113 | pythia.readString("ProcessLevel:resonanceDecays = off"); | |
114 | ||
115 | // No printing of settings, particle data or events. | |
116 | pythia.readString("Init:showProcesses = off"); | |
117 | pythia.readString("Init:showChangedSettings = off"); | |
118 | pythia.readString("Init:showChangedParticleData = off"); | |
119 | pythia.readString("Next:numberCount = 0"); | |
120 | pythia.readString("Next:numberShowInfo = 0"); | |
121 | pythia.readString("Next:numberShowProcess = 0"); | |
122 | pythia.readString("Next:numberShowEvent = 0"); | |
123 | ||
124 | // Debug: show information on cross section maximum and violation. | |
125 | //pythia.readString("PhaseSpace:showSearch = on"); | |
126 | //pythia.readString("PhaseSpace:showViolation = on"); | |
127 | ||
128 | // Loop over processes. | |
129 | for (int iProc = iFirst; iProc <= iLast; ++iProc) { | |
130 | cout << "\n Begin subrun number " << iProc << " : "; | |
131 | ||
132 | // Switch off previous process(es) and switch on new one(s). | |
133 | if (iProc > iFirst) for (int i = iBeg[iProc - 1]; i < iBeg[iProc]; ++i) | |
134 | pythia.readString( processes[i] + " = off" ); | |
135 | for (int i = iBeg[iProc]; i < iBeg[iProc + 1]; ++i) { | |
136 | pythia.readString( processes[i] + " = on" ); | |
137 | if (i > iBeg[iProc]) cout << " + "; | |
138 | cout << processes[i]; | |
139 | } | |
140 | cout << endl; | |
141 | ||
142 | // Switch between SM and MSSM Higgs scenario. | |
143 | if (iProc <= 40) { | |
144 | pythia.readString("Higgs:useBSM = off"); | |
145 | pythia.readString("25:m0 = 200."); | |
146 | } else { | |
147 | pythia.readString("Higgs:useBSM = on"); | |
148 | pythia.readString("25:m0 = 115."); | |
149 | pythia.readString("35:m0 = 300."); | |
150 | pythia.readString("36:m0 = 300."); | |
151 | pythia.readString("37:m0 = 320."); | |
152 | } | |
153 | ||
154 | // Initialize for LHC. | |
155 | pythia.readString("Beams:eCM = 14000."); | |
156 | pythia.init(); | |
157 | ||
158 | // Debug: show initialized resonance data first time around. | |
159 | //if (iProc == iFirst) pythia.particleData.listChanged(true); | |
160 | ||
161 | // Generate events to get cross section statistics. | |
162 | for (int iEvent = 0; iEvent < nEvent; ++iEvent) pythia.next(); | |
163 | ||
164 | // Show statistics. | |
165 | //pythia.stat(); | |
166 | double sigma = pythia.info.sigmaGen(); | |
167 | cout << " Cross section is " << scientific << setprecision(3) | |
168 | << sigma << " and in Pythia6 was " << sigma6[iProc] | |
169 | << ",\n i.e. now is factor >>> " << fixed | |
170 | << sigma / sigma6[iProc] << " <<< different" <<endl; | |
171 | ||
172 | // End of loop over processes. | |
173 | } | |
174 | ||
175 | // Done. | |
176 | return 0; | |
177 | } |