Large-angle production of charged pions with 3–12.9 GeV/cincident protons on nuclear targets

Abstract

Measurements of the double-differential π ± production cross section in the momentum range 100 p 800 MeV/c and angle range 0.35 θ 2.15 rad in proton-beryllium, proton-carbon, proton-aluminium, protoncopper, proton-tin, proton-tantalum, and proton-lead collisions are presented. The data were taken with the large-acceptance HARP detector in the T9 beam line of the CERN PS. The pions were produced by proton beams in a momentum range from 3 to 12.9 GeV/c hitting a target with a thickness of 5% of a nuclear interaction length. Tracking and identification of the produced particles was performed by 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 d 2 σ /(dpdθ ) at six incident proton beam momenta [3, 5, 8, and 8.9 GeV/c (Be only) and 12 and 12.9 GeV/c (Al only)]. They are based on a complete correction of static and dynamic distortions of tracks in the HARP TPC, which allows the complete statistics of the collected data set to be used. The results include and supersede our previously

Optimization of a mercury jet target for a neutrino factory or a muon collider

“…In addition, for constant beam power, the yield is maximum for a beam energy around 7 GeV, but it is within 10% of this maximum for 5 < KE < 12 GeV. This result is consistent with the analysis of a tantalum target by Strait et al [14] in which the cross-section data from the HARP experiment [15] was considered.…”

The Mu2e Muon Beamline

“…The second model was the fit used by MECO to pion data available to them at the time of their analysis. Finally we have also used the more recent pion data from the HARP group [8]. The results are shown in Table 1 and vary from 20 to 30% loss depending on the model.…”

MARS15 code developments driven by the intensity frontier needs

“…It is seen that the proposed parameterization could be applied in broad angular and momentum ranges. It is known that intra-nuclear cascade models have problems with description of the HARP data [3]. The two-source model can be used as an inclusive event generator until LAQGSM [4] will improve description of the low-energy pion production.…”

“…Experimental data of the HARP collaboration [3] covers angles from 20° to 123°. This data could be also successfully fitted by the two-source model with χ 2 /n ~ 1 for any HARP momentum (3,5,8,12 GeV/c). If other measurements at large angles are included into fitting procedure, quality of the fit becomes slightly worse (χ 2 /n ~ 2), but still is acceptable.…”