problem formulation 2. diffraction in fritiof 1.6, fritiof 7.0, urqmd
DESCRIPTION
Simulation of Diffraction Dissociation in Various Models V. Uzhinsky, 27.11.13. Problem formulation 2. Diffraction in Fritiof 1.6, Fritiof 7.0, UrQMD Diquark fragmentation functions Conclusion Consideration. 1. FTF results. Problem formulation. - PowerPoint PPT PresentationTRANSCRIPT
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1. Problem formulation2. Diffraction in Fritiof 1.6, Fritiof 7.0, UrQMD 3.Diquark fragmentation functions
Conclusion Consideration
Simulation of Diffraction Dissociation in Various ModelsV. Uzhinsky, 27.11.13
FTF results
Problem formulation
UrQMD 3.3, pp-interactions
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V. Uzhinsky, arXiv: 1308.0736 [hep-ph]
FTF 9.6, pp-interactions
NA61/SHINE exp. data
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Problem formulation
Fritiof 1.6, Fritiof 7.0, Hijing, UrQMD 3.3, pp-interactions
NA61/SHINE exp. data
UrQMD takes into account the following processes
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Problem formulation
Questions:What is wrong?Diffraction?Production?Fragmentation?Other processes?
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Diffraction in Fritiof 1.6, Fritiof 7.0, UrQMD 3.3
Fritiof 1.6:Md=1.2 GeV, Pt=0.283 GeV/c
Fritiof 7.0:Md=1.2 GeV, Pt=0.1 GeV/c
UrQMD:Md=1.46 GeV, Pt=1.6 GeV/c
Fritiof 7.0, diffraction:
p+p -> p+g+q+qq -> p+Δ+(1232)
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Diffraction in Fritiof 1.6, Fritiof 7.0, UrQMD 3.3
No “resonance” at M=1440 MeV. It is not Roper resonance.
p+p -> p+(n+Pi+)
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Diffraction in Fritiof 1.6, Fritiof 7.0, UrQMD 3.3
UrQMD: No Δ(1232) at high energies! FTF – background.
p+p -> n+(p+Pi+)
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Diffraction in Fritiof 1.6, Fritiof 7.0, UrQMD 3.3
High energies. Ecms=23.77 GeV Step-like UrQMD distributions!
UrQMD O.K. for high masses. FTF underestimates Xs.
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Diffraction in Fritiof 1.6, Fritiof 7.0, UrQMD 3.3
Fritiof 1.6Fritiof and UrQMD
Exp. Data: K. Goulianos and J. Montanha, Phys. Rev. D59 (1999) 114017
Conclusion: Low mass diffraction is wrong in Fritiof-based models. No “resonance” at M=1440 MeV. FTF model: High mass – O.K., Low mass – No!
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Diquark fragmentation functions, Fritiof 1.6
MST(10)=0 ! leading diquark always treated like a unit.
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Diquark fragmentation functions, FTF-Geant4
G4LundStringFragmentation.cc, GetLightConeZ
G4double alund; if(std::abs(PDGEncodingOfDecayParton) < 1000) { // ---------------- Quark fragmentation ---------------------- alund=0.35/GeV/GeV; // Instead of 0.7 because kinks are not considered
G4double zOfMaxyf=alund*Mt2/(alund*Mt2 + 1.); G4double maxYf=(1-zOfMaxyf)/zOfMaxyf * std::exp(-alund*Mt2/zOfMaxyf); G4double z, yf; do { z = zmin + G4UniformRand()*(zmax-zmin); // yf = std::pow(1. - z, blund)/z*std::exp(-alund*Mt2/z); yf = (1-z)/z * std::exp(-alund*Mt2/z); } while (G4UniformRand()*maxYf > yf);
return z; } else { // ---------------- Di-quark fragmentation ---------------------- alund=0.7/GeV/GeV; // 0.7 2.0 G4double z, yf; do { z = zmin + G4UniformRand()*(zmax-zmin); yf = sqr(z-zmin)*(z-zmin)/sqr(zmax-zmin)/(zmax-zmin); } while (G4UniformRand() > yf);
return z; }
Conclusion
1. I am happy that I have found needed line to change in FTF.
2. A new fine tuning of FTF parameters is needed.
3. Low mass diffraction is not simulated correctly in all Fritiof-based models.
4. “Resonance” at M=1440 MeV has to be included in FTF. There are analogous “resonances” in Pi+P and K+P interactions.
5. Diffraction on nuclei can be re-considered now.
ConsiderationOne Pion Exchange Model
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ConsiderationOne Pion Exchange Model
p+p -> p+(n+Pi+)S.D. Drell and K. Hiida, Phys. Rev. Lett. 7 (1961)199.R. Deck, Phys. Rev. Lett. 13 (1964) 1969.
How will be changed the diagrams andresults in the case of hA interactions?
C. Alvear, A.C.B. Antunes, Nuclear Physics A 615 (1997) 537A. Bujak et al., Phys. Rev. D23 (1981) 1911.
For FTF
ConsiderationDiffraction at LHC
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Totem experiment:
P+P -> P+P* -> P+N+ Pi+ ???
Pi+ can be registered instead of P!? It can be in low mass diffraction.
Conclusion
1. I am happy that I have found needed line to change in FTF.
2. A new fine tuning of FTF parameters is needed.
3. Low mass diffraction is not simulated correctly in all Fritiof-based models.
4. “Resonance” at M=1440 MeV has to be included in FTF. There are analogous “resonances” in Pi+P and K+P interactions.
5. Diffraction on nuclei can be re-considered now.
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