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Improvement of FTF model V. Uzhinsky, 22.09.10

Improvement of FTF model V. Uzhinsky, 22.09.10. Short description of the Fritiof (FTF) model Problem formulation Phase space restrictions at low mass string fragmentation Correction of intra-nuclear interaction number Tuning of reggeon cascading parameters The best partner of FTF Conclusion.

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Improvement of FTF model V. Uzhinsky, 22.09.10

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  1. Improvement of FTF modelV. Uzhinsky, 22.09.10 • Short description of the Fritiof (FTF) model • Problem formulation • Phase space restrictions at low mass string fragmentation • Correction of intra-nuclear interaction number • Tuning of reggeon cascading parameters • The best partner of FTF • Conclusion 1

  2. 1. Short description of the models 2 FRITIOF model B. Andersson et al., Nucl. Phys. B281 (1987) 289; B. Nilsson-Almquist and E. Stenlund, Comp. Phys. Commun. 43 (1987)387. Hadron-hadron interactions are modeled as binary kinematics a+b →a’ + b’, ma’> ma mb’> mb where a’ and b’ are excited states of the initial hadrons a and b. In hadron-nucleus interactions the excited hadrons can interact with other nucleons of nucleus and increases mass. The probability of multiple collisions is calculated in Glauber approach. The variant used in the Fritiof model is enlarged with elastic re-scatterings of hadrons. The excited states are considered as QCD-strings, and the LUND model is used for their fragmentation. Key parameters

  3. 1. Short description of the models 3 FRITIOF model Limits are different for various implementations (UrQMD, Hijing). Fragmentation models are different too. These lead to various predictions

  4. 2. Problem formulation Quark exchange was introduced. It improved the results. 4

  5. 2. Problem formulation Separate simulation of the single diffraction and non diffraction interactions 5

  6. 3. Phase space restrictions at low mass string fragmentation pp→ppπ+π- Final state: single diffraction P(Δ++π-) XXX P(Δ0π+) X P(Pπ+π-) 3 P(Pρ0) 5 SplitLast Too many delta’s! P(B3/2)=P(B1/2)? PS~q2 part. decay G4bool G4LundStringFragmentation::SplitLast(G4FragmentingString * string, G4KineticTrackVector * LeftVector, G4KineticTrackVector * RightVector) { //... perform last cluster decay NumberOf_FS=0; for(G4int ProdQ=1; ProdQ < 4; ProdQ++) { LeftHadron=G4ParticleTable::GetParticleTable()->FindParticle(SignQ* Meson[AbsIDquark-1][ProdQ-1][StateQ]); RightHadron=G4ParticleTable::GetParticleTable()->FindParticle(SignDiQ* Baryon[Di_q1-1][Di_q2-1][ProdQ-1][StateDiQ]); 6

  7. 3. Phase space restrictions at low mass string fragmentation G4double FS_Psqr=lambda(StringMassSqr,sqr(LeftHadronMass), sqr(RightHadronMass)); FS_Weight[NumberOf_FS]=std::sqrt(FS_Psqr)* MesonWeight[AbsIDquark-1][ProdQ-1][StateQ]* BaryonWeight[Di_q1-1][Di_q2-1][ProdQ-1][StateDiQ]* Prob_QQbar[ProdQ-1]; ------------------------------------------------------------------------------------------------------------------- G4LundStringFragmentation::G4LundStringFragmentation() //-------------------------- Meson[0][0][0]=111; // dbar-d Pi0 MesonWeight[0][0][0]=pspin_meson*(1.-scalarMesonMix[0]); Meson[0][0][1]=221; // dbar-d Eta MesonWeight[0][0][1]=pspin_meson*(scalarMesonMix[0]-scalarMesonMix[1]); Meson[0][0][2]=331; // dbar-d EtaPrime MesonWeight[0][0][2]=pspin_meson*(scalarMesonMix[1]); Meson[0][0][3]=113; // dbar-d Rho0 MesonWeight[0][0][3]=(1.-pspin_meson)*(1.-vectorMesonMix[0]); Meson[0][0][4]=223; // dbar-d Omega MesonWeight[0][0][4]=(1.-pspin_meson)*(vectorMesonMix[0]); //-------------------------- 7

  8. 3. Phase space restrictions at low mass string fragmentation 8 PP interaction, channel cross sections

  9. 3. Phase space restrictions at low mass string fragmentation 9 PP interaction, topological cross sections

  10. 3. Phase space restrictions at low mass string fragmentation 10 PP interaction, inclusive cross sections

  11. 3. Phase space restrictions at low mass string fragmentation 11 PP interaction, inclusive cross sections

  12. 3. Phase space restrictions at low mass string fragmentation 12 PP interaction, inclusive cross sections

  13. 3. Phase space restrictions at low mass string fragmentation Before After Check of inclusive cross sections for PN interactions, HARP-CDP data 13

  14. 3. Phase space restrictions at low mass string fragmentation Before After Check of inclusive cross sections for PN interactions, HARP-CDP data 14

  15. 4. Correction of intra-nuclear interaction number PROBLEM! 15

  16. Suggestion: Correction of intra-nuclear interaction number Low energy, Std. cascade. Cascade+ QGS High energy, Std. QGS. Competition of planar and non-planar diagrams. There was only 1 paper on the subject by K. Boreskov and A. Kaidalov S.Yu. Shmakov, V.V. Uzhinsky, Zeit. fur Phys. C36:77,1987. Transverse energy spectrum in the central region of interactions: calculations using various models, AQM is equivalent to the MCEP in which the leading/projecting hadrons can interact not more than three times.// Max. cross section method: W.A. Coleman: Nucl. Sci. Eng. 32 (1968) 76 Nmax=Plab/4 (GeV/c) 16

  17. 4. Correction of intra-nuclear interaction number Nmax=1, Plab=3, 5 GeV/c: Nmax=2, Plab=8 GeV/c: Nmax=3, Plab=12 17

  18. 4. Correction of intra-nuclear interaction number Problem with Pi+, maybe the binary cascade will help. 18

  19. 4. Correction of intra-nuclear interaction number All O.K. with Pi- ! Nmax=Plab/4 (GeV/c) 19

  20. 4. Correction of intra-nuclear interaction number Problem with Pi+ at low energies, maybe the binary cascade will help. 20

  21. 5.Tuning of reggeon cascading parameters Model of nuclear disintegration in high-energy nucleus nucleus interactions. K. Abdel-Waged, V.V. Uzhinsky Phys.Atom.Nucl.60:828-840,1997, Yad.Fiz.60:925-937,1997. Si+A, 14.7 GeV/N T – energy in ZDC 21

  22. 5.Tuning of reggeon cascading parameters Complex analysis of gold interactions with photoemulsion nuclei at 10.7-GeV/nucleon within the framework of cascade and FRITIOF models.By EMU-01 Collaboration (M.I. Adamovich et al.). 1997. Zeit. fur Phys.A358:337-351,1997. Main parameters: Cnd, dx, pT2 22

  23. 5.Tuning of reggeon cascading parameters Unexpected results of the tuning Clear signal of a transition regime! The transition takes place at Plab= 4-5 GeV/c 23

  24. 5.Tuning of reggeon cascading parameters All is beautiful! 24

  25. 6. The best partner, Bertini? pTa->p+X Transition region 3 – 8 GeV/c 25

  26. 6. The best partner, Bertini? pTa->Pip+X 26

  27. 6. The best partner, Binary? pCu->p+X 27

  28. 6. The best partner, Binary? pTa->p+X 28

  29. 6. The best partner, Chips? pTa->p+X 29

  30. 6. The best partner, Chips? pTa->Pip+X 30

  31. Conclusion 1. 3 new things are introduced in FTF for pp- and pA-interactions: a) Phase space restrictions at low mass string fragmentation b) Correction of multiplicity of intra-nuclear collisions c) Tuning of RTIM parameters 2.Good results are obtained for pp- and pA-interactions, especially for description of HARP-CDP data. The description of HARP-CDP data on pA-interactions (Be, C, Cu, Ta, Pb) is the best among other models! 3. The best low energy partner of FTF is the Bertini model. The corresponding transition region is 3 – 8 GeV/c. 4. It would be well to improve the Bertini model. Improving of the Binary model is heavily desirable! 5. A strong indication on transition regime realization is obtained! Nmax=Plab/4 (GeV/c) 31

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