Results from HARP-CDP or The irresistible Power of Truth

by Friedrich Dydak (CERN)

Tuesday 24 Jun 2008, 16:30 → 17:30 Europe/Zurich

Main Auditorium** (CERN)

Surprisingly, cross-sections of hadron production off nuclei are uncertain by factors of up to three. A systematic measurement programme was undertaken with the HARP spectrometer at CERN, motivated by the need to have precise cross-sections for the understanding of the 'LSND puzzle', for the design of a neutrino factory, for the Monte Carlo simulation of LHC data, and for other issues. We present measurements of the ratio of negative to positive pions produced by protons with kinetic energy of 800 MeV, and discuss them in the context of our simulation of signals and backgrounds in the LSND experiment. We present double-differential cross-sections measured in the large-angle HARP spectrometer. Our cross-sections disagree grossly with those being published by the 'HARP Collaboration'. The origin of the disagreement is understood and we shall explain what went wrong in the data analysis of the HARP Collaboration. Our measurements were used to test hadron production models in the GEANT4 simulation tool kit. We observe that all currently implemented models disagree strongly with our data.

Joint PP/EP seminar - 2008 http://smaria.home.cern.ch/smaria/ppep/ppep.htm

Slides PowerOfTruth.pdf PowerOfTruth.ppt