MonteCarlo Simulation of MesonNucleon and MesonNucleus Interactions at High Energies

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Monte-Carlo Simulation of Meson-Nucleon and
Meson-Nucleus Interactions at High Energies
A. Galoyan, V. Uzhinsky
Joint Institute for Nuclear Research
Dubna, Russia, 2007
FRITIOF model (1987)

• 
  

Monte Carlo event generators ISAJET, ART,
RQMD, PYTHIA and UrQMD
Quark Gluon String Model QGSM
QGSM, VENUS, DPMJET, FLUKA, QGSM-G
implemented at GEANT4
package
At super high energies hydro-dynamical models
and HIJING, AMPT, HSD, UrQMD_2.1
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FRITIOF model
B. Andersson et al., Nucl. Phys. \bf B281
(1987) 289 B. Nilsson-Almquist and E. Stenlund,
Comp. Phys. Commun. \bf 43 (1987) 387.
It is assumed binary kinematics of hadron-hadron
interactions a b ?a b,
magt ma mbgt mb where a ? b are
excited states of 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 used variant of model Fritiof is
enlarged with elastic re-scatterings of hadrons.
The excited states are considered as
QCD-strings and LUND model are used for their
fragmentation. Modified model Fritiof is added
by reggeon cascade model. The probability of
involving of nucleon in reggeon cascade is
WCnde-r2/rnd2 , where r is distance between
involving and wounded nucleons. It was chosen
Cnd 1, rnd1.2 Fm.
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Interactions if rijlt vsij/p
rij1 - 3 fm!
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Quark Gluon String Model
A.B.Kaidalov and K.A.Ter-Martirosian, Phys.
Lett. B117 (1982) 247 A.B.Kaidalov, Phys. Lett.
B116 (1982) 459 A.B.Kaidalov and
K.A.Ter-Martirosian, Yad. Fiz. 39 (1984) 1545
(Sov. J. Nucl. Phys. 39 (1984) 979 A.B.Kaidalov
and K.A.Ter-Martirosyan, Yad. Fiz. 40 (1984) 211
(Sov. J. Nucl. Phys. \bf 40 (1984)
135) A.B.Kaidalov and O.I.Piskunova, Zeit. fur
Phys. C30 (1986) 145 A.Capella, J.Kwiecinski,
J.TranThanhVan, Phys. Lett. B108 (1982)
347 A.Capella, C.Pajares, A.V.Ramallo, Nucl.
Phys. B241 (1984) 75 A.Capella et al. Phys.
Rept. 236 (1994) 225.
In the model various cuts of reggeon diagrams are
connected with color exchanges. Due to the
exchanges strings formation takes place between
constituents of colliding hadrons. Quark momentum
distributions and fragmentation functions are
determined by behavior of reggeon planar
diagrams. So, we can say
QGSM Regge phenomenology
Parton ideas
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FRITIOF Model QGSM
M1
M2

• Questions
• What to do with binary
• channels?
• 2. M low for sampling?
• 3. M low of string masses?
• 4. How to treat diffraction?
• 5. Mass distribution?
• 6. For MN interactions
• most points are at the
• left lower corner!!!
• 7. Etc.

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Meson - Nucleon interactions
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Meson - Nucleon interactions
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In central region of XF the processes with
2-strings creation are dominated. UrQMD takes
into account a formation of s-channel resonances
(pp-gtR) It is desirable to include in FRITIOF
and QGSM s-channel resonances (pp-gtR, pp-gtR
p, pp-gtRp, pp-gtR1R2 ) and planar
diagrams. The total cross section of
meson-nucleon interaction is represented as sum
of positive defined terms
stotMNsel sdifM sdifN s2str sann For
pp-interactions sann ?ann, for
p-p-interactions sann 2?ann
stot pp sel sdifM sdifN s2str c?ann
stot p-p sel sdifM sdifN
s2str 2c?ann
and c?ann stot p-p - stot pp .
According to the optical theorem stot 2 Im
M(s,0). In reggeon approach
Mpp (s.t) Mp(s,t) Mf(s.t)
M?(s,t) In the case total cross section is not
the sum of positive defined terms. sann in pp
interaction 10, 9, 5 () at 8, 16, 100
(GeV/c)
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Yields of processes in p spectra
2 string processes are responsible for
disagreement of calculations and exp. data in
the region of xF 0.3-1
Hypothesis on string
disorientation
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Spectra of p and p- in p-A-interactions at 100
GeV/c