p-p and p-air interaction data in uv3.00 or later

There is some difference in the ad hoc model before and after v3.0. In this page, you can see some essential points of the changes in Version 3 including those of the new Lund code. The new Lund code consists of 4 programs: Fritiof v7.02, Jetset 7.3, Pythia 5.5, ariadone 4.02.

As in the figures in the previous page, x is defined simply by the ratio of the energy of a secondary particle to the incident proton energy in the laboratory system.
  1. Nucleon x-distribution at 100 GeV xdN/dx is plotted for old Lund, ad-hoc and new Lund models.
  2. Nucleon x-distribution at higher energies We see disappearing diffractive peak for the new Lund model as energy goes higher.
  3. Multiplicity distribution by the new Lund code with kfr(7)=2 for 10^18 eV pp collisions We see strange double peaks so its not recommended to use kfr(7)=2.
  4. Energy dependence of multiplicity by ad hoc model and new Lund model. It is interesting to note that the new Lund result for pp collisions is well fitted by the QCD predicted energy dependence. (exp(sqrt(log(s))). There is a small reduction of multiplicity in the ad hoc model (10 %) as compared to the older versions. However, this effect in observation might be seen only in low energy muons as a few percent reduction of the number. The lines for the ad hoc model are by approximate formulas shown in the fig. and must be used at E > > 10 GeV.
  5. Comparison of pseudo rapidity The ad hoc model results are compared with the UA5 minimum bias (inelastic) data.
  6. The same comparison as above by new Lund code. At lower energies, the agreement with the experimental data is not so bad, but at higher energies,... If some one knows how to tune Fritiof v7.02, let me know.
  7. The epseudo rapidity for pp collisions at 10^12, 10^15, 10^18, and 10^21 eV. The multiplicity reduction from the fig. given in the previous page is seen only in the central region
  8. The pseudo rapidity for p-air( Nitrogen) collisionsWe see some skew (wider distribution in the negative side) due to the nucleus effect.
  9. Transverse momentum distributions of pions + kaons at various energies. This large Pt tail is one of the improved points in V.3
  10. The X distribution of pions + kaons This is unchanged from the older versions.
  11. log10(x) distribution of pions + kaons for pp collisions. As in the case of the pseudo rapidity, reduction of multiplicity from the older versions is only in the central part.
  12. The same for p-air collisions