Download ppt - Problem formulation 2. Diffraction in Fritiof 1.6, Fritiof 7.0, UrQMD

$Page 1: Problem formulation 2. Diffraction in Fritiof 1.6, Fritiof 7.0, UrQMD$
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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

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Problem formulation

Fritiof 1.6, Fritiof 7.0, Hijing, UrQMD 3.3, pp-interactions

NA49 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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No “resonance” at M=1440 MeV. It is not Roper resonance.

p+p -> p+(n+Pi+)

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UrQMD: No Δ(1232) at high energies! FTF – background.

p+p -> n+(p+Pi+)

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High energies. Ecms=23.77 GeV Step-like UrQMD distributions!

UrQMD O.K. for high masses. FTF underestimates Xs.

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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, UrQMD 3.3

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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; }

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Diquark fragmentation functions, FTF-Geant4

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

Diffraction on nuclei

NA49 exp. data 17

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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