Forward pions production from HARP experiment (3-12 GeV/c) geant ref-03 Part I: Be, C, Al

HARP experiment PS214 (CERN) – Thin targets – HARP and HARP-CDP groups – Energies 3-15 GeV/c – Protons and pions interactions – Protons and pions production (FW+LA) Data on forward particles from forward protons – CDP group has no analyses on this data – Large uncertainty for pi+ on hard targets Results with test35 for 9.5ref03 Full run of test35 produces about 2000 plots 2

FORWARD PROTONS PRODUCTION HARP collaboration. Phys.Rev. C82, (2010) 3

BERT provides reasonable profiles FTFP a bit overestimates protons 4

BERT provides reasonable profiles FTFP overestimates protons more 5

Conclusions on protons BERT reproduces better data on Be, C, and Al FTFP overestimates in most cases (Al 8 and 12 GeV are very problematic) QGSB cannot reproduce data 6

FORWARD PIONS PRODUCTION HARP collaboration. Phys.Rev. C80, (2009) HARP collaboration. CERN-PH-EP/

BERT and FTFP - reasonable results Pi+ 5 GeV/c 8

Pi- 5 GeV/c FTFP reproduces C data better LHEP reproduces C data better 9

FTFP provides good results BERT is good for Al BERT underestimates at C LHEP reproduces C data better 10 Pi- 8 GeV/c

QGSB is the most precise model here BERT and FTFP overestimate pi+ 11 Pi+ 8 GeV/c

BERT and FTFP overestimates pi- 12 Pi- 12 GeV/c Be-data FTFP reproduces better LHEP reproduces better

Data are not good QGSB reproduces better 13 Pi+ 12 GeV/c C-Data FTFP reproduces better

Conclusions on pions BERT reproduces data – overestimates pi+ and underestimates pi- FTFP reproduces data – Overestimates pi+ and underestimates pi- QGSB is better for the pion production than for the proton production LHEP reasonably reproduces experimental data 14