The HARP collaboration has presented measurements of the double-differential pi+/pi- production cross-section in the range of momentum 100 MeV/c <= p 800 MeV/c and angle 0.35 rad <= theta <= 2.15 rad with proton beams hitting thin nuclear targets. In many applications the extrapolation to long targets is necessary. In this paper the analysis of data taken with long (one interaction length) solid cylindrical targets made of carbon, tantalum and lead is presented. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN PS. The secondary pions were produced by beams of protons with momenta 5 GeV/c, 8 GeV/c and 12 GeV/c. The tracking and identification of the produced particles were performed using a small-radius cylindrical time projection chamber (TPC) placed inside a solenoidal magnet. Incident protons were identified by an elaborate system of beam detectors. Results are obtained for the double-differential yields per target nucleon d2 sigma / dp dtheta. The measurements are compared with predictions of the MARS and GEANT4 Monte Carlo simulations.
Differential cross section for PI+ production with a C target in the angular range 0.35 to 0.55 radians.. The errors are the square root of the diagonal elements of the covariant matrix.
Differential cross section for PI+ production with a C target in the angular range 0.55 to 0.75 radians.. The errors are the square root of the diagonal elements of the covariant matrix.
Differential cross section for PI+ production with a C target in the angular range 0.75 to 0.95 radians.. The errors are the square root of the diagonal elements of the covariant matrix.
Measurements of the double-differential $\pi^{\pm}$ production cross-section in the range of momentum $100 \MeVc \leq p < 800 \MeVc$ and angle $0.35 \rad \leq \theta < 2.15 \rad$ in proton--beryllium, proton--aluminium and proton--lead collisions are presented. The data were taken with the HARP detector in the T9 beam line of the CERN PS. The pions were produced by proton beams in a momentum range from 3 \GeVc to 12.9 \GeVc hitting a target with a thickness of 5% of a nuclear interaction length. The tracking and identification of the produced particles was performed using a small-radius cylindrical time projection chamber (TPC) placed inside a solenoidal magnet. Incident particles were identified by an elaborate system of beam detectors. Results are obtained for the double-differential cross-sections at six incident proton beam momenta (3 \GeVc, 5 \GeVc, 8 \GeVc, 8.9 \GeVc (Be only), 12 \GeVc and 12.9 \GeVc (Al only)) and compared to previously available data.
Double-differential cross section for PI+ production from BE in the LAB system for PI+ polar angle from 0.35 to 0.55 radians.
Double-differential cross section for PI+ production from BE in the LAB system for PI+ polar angle from 0.55 to 0.75 radians.
Double-differential cross section for PI+ production from BE in the LAB system for PI+ polar angle from 0.75 to 0.95 radians.
Forum