TARGET A hadronic interaction model for studying inclusive muon and neutrino fluxes

1. TARGETA hadronic interaction model for studying inclusive muon and neutrino fluxes Ralph Engel (Forschungszentrum Karlsruhe, Germany) Giles Barr, Thomas K. Gaisser, Simon Robbins and Todor Stanev

2. Motivation and outline TARGET 3D (old version: 2.1, current version: 2.4) very flexible and tunable hadronic interaction model simple and fast Monte Carlo code optimization for inclusive muon/neutrino fluxes event generation structure and recent improvements comparison to data application: L3+C muon flux Ralph Engel, ICRC 2003

3. Event generation in TARGET simulation of one proton-air interaction event type leading particle (projectile) nucleons from target nucleus fast pions and kaons (correlated with leading particle) slow pions and kaons (correlated with target nucleons) baryon-antibaryon pair production central pion and kaon production multiplicity determined by energy conservation cross sections: PDG data and Glauber approach Ralph Engel, ICRC 2003

4. Event generation in TARGET simulation of one proton-air interaction event type leading particle (projectile) nucleons from target nucleus fast pions and kaons (correlated with leading particle) slow pions and kaons (correlated with target nucleons) baryon-antibaryon pair production central pion and kaon production multiplicity determined by energy conservation cross sections: PDG data and Glauber approach Ralph Engel, ICRC 2003

5. Nucleons: projectile/target fragmentation old version: no target fragmentation nucleons tuned to Eichten et al. data data converted from double-differential cross sections Ralph Engel, ICRC 2003

6. Nucleons: projectile/target fragmentation new version: target fragmentation nucleons target and projectile nucleons symmetric Ralph Engel, ICRC 2003

7. Nucleons: comparison to other models large differences between models inconsistent data not very important for flux calculations (Gaisser & Honda, Ann. Rev. Nucl. Part. Sci. 52 (2002) 153) Ralph Engel, ICRC 2003

8. Low-energy pion production (1) full phase space measurement recoil nucleons change energy available for particle production Ralph Engel, ICRC 2003

9. Low-energy pion production (2) full phase space measurement slow pions from fragmentation of target nucleons Ralph Engel, ICRC 2003

10. Low-energy pion production (3) full phase space measurement pion multiplicity at small x too high? Ralph Engel, ICRC 2003

11. Baryon-antibaryon pair production no data for nuclear targets scaled p-p cross sections and distributions used production of anti- protons, neutrons and lambdas Ralph Engel, ICRC 2003

12. Comparison with p-Be at 24 GeV (1) almost no change of distributions at higher energy Ralph Engel, ICRC 2003

13. Comparison with p-Be at 24 GeV (2) almost no change of distributions at higher energy Ralph Engel, ICRC 2003

14. Comparison to L3+C muon measurement TARGET predictions: good description of L3+C data SIBYLL gives similarly good description QGSjet: too few fast pions (see talks by M. Unger, HE 2.1.10 and T. Stanev, HE 2.4.9) Ralph Engel, ICRC 2003

15. Comparison of high-energy models inclusive charged pion spectra p-air collisions, Elab = 500 GeV fast pions very important Ralph Engel, ICRC 2003

16. Summary and outlook TARGET: simple and very flexible event generator version 2.4: implementation of processes needed for comparison to forthcoming HARP/NA49 data improved description of low-energy data minor changes at high energy plans: additional fine-tuning and release of new version Ralph Engel, ICRC 2003

17. Pions: comparison to other models large differences between models at low and high x some data sets inconsistent very important for flux calculations (Gaisser & Honda, Ann. Rev. Nucl. Part. Sci. 52 (2002) 153) Ralph Engel, ICRC 2003

18. Muon flux charge ratio charge ratio very sensitive to leading particle production slightly too many fast neg. pions in new version of TARGET fine-tuning in progress Ralph Engel, ICRC 2003