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Experimental data: Z. Strugalski et al. JINR preprints, E1-81-578 (1981),

Validation of G4 Hadronic Models for π Xe Experimental Data in the Region Plab=2 – 8 GeV/c V. Uzhinsky (CERN and LIT JINR). Experimental data: Z. Strugalski et al. JINR preprints, E1-81-578 (1981), E1-81-803 (1981).

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Experimental data: Z. Strugalski et al. JINR preprints, E1-81-578 (1981),

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  1. Validation of G4 Hadronic Models for πXe Experimental Data in the Region Plab=2 – 8 GeV/cV. Uzhinsky (CERN and LIT JINR) Experimental data: Z. Strugalski et al. JINR preprints, E1-81-578 (1981), E1-81-803 (1981). Reaction Chamber Beam #Photos #Selected Instit. Pi++Xe, 26 liters, 2.34, 20000, 6110, JINR Pi-+Xe, 180 liters, 3.5, 40000, 5487, ITEP Pi-+Xe, 26 liters, 5.0, 6000, 1468, ITEP Pi-+Xe, 26 Liters, 8.0, 9000, 1994, ITEP Protons: E= 20/30 – 250/300/400 MeV; Neutrons ? Pi+ : E> 0. – 100 MeV; Pi- : E>10/15 -60 MeV: Pi0->2γ: E>0. MeV. Measured: Multiplicity distributions of P, π+-0, π0; Multiplicity correlations. 1

  2. Low energy G4 models: Bertini, Binary, LEPAR, QGS+Binary Multiplicity distributions of protons: Bertini model works well below 5 GeV, QGS+Bic above 5 GeV. 2

  3. Low energy G4 models: Bertini, Binary, LEPAR, QGS+Binary Multiplicity distributions of Pi+-0: 3 Bertini and Binary models works well below 5 GeV, QGS+Bic above 5 GeV.

  4. Low energy G4 models: Bertini, Binary, LEPAR, QGS+Binary Multiplicity distributions of Pi0: 4

  5. Low energy G4 models: Bertini, Binary, LEPAR, QGS+Binary Multiplicity correlations: Pi+-0 - Protons 5 Bertini model works well, but there is too strong absorption.

  6. Low energy G4 models: Bertini, Binary, LEPAR, QGS+Binary Multiplicity correlations: Pi0 - Protons 6 Bertini model works reasonable well.

  7. Low energy G4 models: Bertini, Binary, LEPAR, QGS+Binary Multiplicity correlations: Protons –Pi+-0 7 Bertini model works reasonable well below 5 GeV.

  8. Low energy G4 models: Comparison of G4 models and Dubna Cascade Model Multiplicity distribution: Protons 8 Bertini model works as DCM.

  9. Low energy G4 models: Comparison of G4 models and Dubna Cascade Model Multiplicity distribution: Pi+-0 9 DCM is not perfect!

  10. Low energy G4 models: Improvement of the Bertini model The most important parameters – absorption cross section of meson by di-nucleons (π+(NN)->NN) geant4-09-01-ref-02/source/processes/hadronic/models/cascade/cascade/src grep -i absorptionCros * ------------------------- G4BertiniNucleiModel.cc: abs_sec = absorptionCrosSection(ekin, ptype); // PP G4BertiniNucleiModel.cc: abs_sec = absorptionCrosSection(ekin, ptype); // PN G4BertiniNucleiModel.cc: abs_sec = absorptionCrosSection(ekin, ptype); // NN G4CascadSpecialFunctions.cc:G4double G4CascadSpecialFunctions::absorptionCrosSection(G4double G4NucleiModel.cc: abs_sec = absorptionCrosSection(ekin, ptype); // PP G4NucleiModel.cc: abs_sec = absorptionCrosSection(ekin, ptype); // PN G4NucleiModel.cc: abs_sec = absorptionCrosSection(ekin, ptype); // NN 10

  11. Low energy G4 models: Improvement of the Bertini model The most important parameters – absorption cross section of meson by di-nucleons (π+(NN)->NN) G4CascadSpecialFunctions.cc --------------------------------------------- G4double G4CascadSpecialFunctions::absorptionCrosSection(G4double e,int type) { G4int verboseLevel = 2; if (verboseLevel > 3) { G4cout << " >>> G4CascadSpecialFunctions::absorptionCrosSection type:" << type <<G4endl; } const G4double corr_fac = 0.1; // 0.2; // Uzhi 7.11.08 G4double csec = 0.0; if (e < 0.3) { csec = 0.1106 / std::sqrt(e) - 0.8 + 0.08 / ((e - 0.123) * (e - 0.123) + 0.0056); } else if (e < 1.0) { csec = 3.6735 * (1.0 - e) * (1.0 - e); }; if (csec < 0.0) csec = 0.0; if (verboseLevel > 2) { G4cout << " ekin " << e << " abs. csec " << corr_fac * csec << G4endl; } return corr_fac * csec; } 11

  12. Low energy G4 models: Improvement of the Bertini model Multiplicity distribution: Protons 12 There is enough space!

  13. Low energy G4 models: Improvement of the Bertini model Multiplicity distribution: Pi+-0 13 There is enough space!

  14. Low energy G4 models: Improvement of the Bertini model Multiplicity correlation: Pi+-0 - Protons 14 The Bertini model is improved below 5 GeV!

  15. Low energy G4 models: Improvement of the Bertini model Multiplicity correlation: Protons – Pi+-0 15

  16. High energy G4 models: HEPAR, QGSP, QGS_Bic, QGSC, FTFP Multiplicity distributions: Protons 16 QGS_Bic is well above 5 GeV. QGSC works well!

  17. High energy G4 models: HEPAR, QGSP, QGS_Bic, QGSC, FTFP Multiplicity distributions: Pi+-0 17 QGS_Bic is well above 5 GeV. QGSC does not work!

  18. High energy G4 models: HEPAR, QGSP, QGS_Bic, QGSC, FTFP Multiplicity correlations: Pi+-0 - Protons 18 Only QGS_Bic works well above 5 GeV.

  19. High energy G4 models: FTFP+Binary Multiplicity distributions: Protons 19 The combination works well above 3 GeV.

  20. High energy G4 models: FTFP+Binary Multiplicity distributions: Pi+-0 20 There is not enough absorption in the combination.

  21. High energy G4 models: FTFP+Binary Multiplicity correlations: Pi+-0 - Protons 20 There is not enough absorption in the combination.

  22. Conclusion 1. The Bertini model works well below 5 GeV. It can be improved. It works as well as Dubna cascade model. 2. There is not enough pion absorption in the Binary model. 3. QGS+Binary works well above 5 GeV. 4. FTF+Binary is well above 3 GeV. If the Binary model will be improved, the combination will work better. 5. LEPAR and HEPAR can not be applied for such data. Questions: Who was busy with a tuning of the absorption? Are there any restrictions on the tuning? How to improve the Binary cascade model? 21

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