Measurements of the double-differential
π
±
production cross-section in the range of momentum
0.5
GeV
/
c
⩽
p
⩽
8.0
GeV
/
c
and angle
0.025
rad
⩽
θ
⩽
0.25
rad
in interactions of charged pions on ...beryllium, carbon, aluminium, copper, tin, tantalum and lead are presented. These data represent the first experimental campaign to systematically measure forward pion hadroproduction.
The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN PS. Incident particles, impinging on a 5% nuclear interaction length target, were identified by an elaborate system of beam detectors. The tracking and identification of the produced particles was performed using the forward spectrometer of the HARP detector. Results are obtained for the double-differential cross-sections
d
2
σ
/
d
p
d
Ω
mainly at four incident pion beam momenta (3 GeV/
c, 5 GeV/
c, 8 GeV/
c and 12 GeV/
c). The measurements are compared with the GEANT4 and MARS Monte Carlo simulation.
We report on a search for a phase transition from ordinary nuclear matter to a state of deconfined quarks and gluons as predicted by lattice QCD calculations. A new measurement of charmonium ...production in Pb-Pb interactions at 158 GeV/
c per nucleon agrees with our previous results and confirms the anomalous J/
ψ suppression we had already observed on a significantly smaller data sample. New event selection and analysis techniques show that, for peripheral collisions, the J/
ψ cross-section per nucleon-nucleon collision agrees with the precise suppression pattern inferred from a wide range of measurements extending from p-p up to S-U collisions. As the collisions become more central, the Pb-Pb cross-section exhibits a clear departure from this normal behaviour. The onset of the anomalous J/
ψ suppression reported here is the first clear observation of a threshold effect in heavy ion collisions and can be considered as a strong indication of the production of a deconfined quark-gluon phase in central Pb-Pb collisions.
Aims. We investigate the extension of the very high-energy spectral tail of the Crab Pulsar at energies above 400 GeV. Methods. We analyzed ~320 h of good-quality Crab data obtained with the MAGIC ...telescope from February 2007 to April 2014. Results. We report the most energetic pulsed emission ever detected from the Crab Pulsar reaching up to 1.5 TeV. The pulse profile shows two narrow peaks synchronized with those measured in the GeV energy range. The spectra of the two peaks follow two different power-law functions from 70 GeV up to 1.5 TeV and connect smoothly with the spectra measured above 10 GeV by the Large Area Telescope (LAT) on board the Fermi satellite. When making a joint fit of the LAT and MAGIC data above 10 GeV the photon indices of the spectra differ by 0.5 ± 0.1. Conclusions. Using data from the MAGIC telescopes we measured the most energetic pulsed photons from a pulsar to date. Such TeV pulsed photons require a parent population of electrons with a Lorentz factor of at least 5 × 106. These results strongly suggest IC scattering off low-energy photons as the emission mechanism and a gamma-ray production region in the vicinity of the light cylinder.
Measurements of the double-differential π
±
production cross-section in the range of momentum 100 MeV/c≤p< 800 MeV/c and angle 0.35 rad ≤θ< 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 GeV/c to 12.9 GeV/c 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 d
2
σ/dpdθ at six incident proton beam momenta (3 GeV/c, 5 GeV/c, 8 GeV/c, 8.9 GeV/c (Be only), 12 GeV/c and 12.9 GeV/c (Al only)) and compared to previously available data.
The problem of computer aided design and fabrication of means of measurement for effective technological preparation of machine-building manufacture under rapidly varying production conditions is ...examined. The operating principles, algorithm content, choice of structural elements of designed pieces, and data storage and output structure for computer aided design and fabrication of measuring instruments are presented. Results from a practical application of this system to the production of machinery are given.
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