The HARP experiment at CERN is performing extensive measurements ofhadron production cross sections and secondary particle yieldsin the energy range 2-15 GeV over the full solid angle, usinga large set of cryogenic and solid targets.Hadron production in this kinematic region is a relevant ingredient inseveral branches of neutrino physics, such as characterisation of neutrinobeams, precise prediction of atmospheric neutrino fluxes, andquantification of pion production and capture for neutrino factory design.An overall precision of few percent is required from the experimentto reach the final aim.The HARP experimental layout comprises two spectrometers to perform momentummeasurement of the secondaries produced in the target.The so called large-angle spectrometer is housing the target and a timeprojection chamber, while the forward spectrometer is equipped with a setof drift chambers and a large-aperture dipole magnet.The time projection chamber allows for track momentum measurementbelow 1 GeV/c at large-angle (including backward-going) tracks.High-momentum small-angle particles passing through the dipolemagnet are measured by the drift chambers.The track momentum reconstruction in the spectrometers is complementedby a set of particle identification detectors (threshold Cerenkov counter,time-of-flight, electromagnetic calorimeter etc.) that allow forparticle type discrimination with some redundancy.About 30 TB of data corresponding to 400 millions of events have beensuccessfully collected during the two years of experiment.First measurements of hadron production cross sections in the forward region(up to about 300 mrad), using the MiniBooNE and K2K replica targetsand a proton beam of respectively 8.9 and 12.9 GeV/c, will be reported.This is an appealing physics case, given the immediate interest for thoseexperiments and for the neutrino community. A preliminary analysis in thelarge angle region on elastic scattering events produced with the cryogenichydrogen target at 3 GeV/c beam momentum will also be presented.
Tonazzo, A. (2004). Measurements of hadron production cross sections and secondary particle yields in the energy range 2-15 GeV using neutrino beam targets.