Two-particle correlations in azimuthal angle and pseudorapidity in inelastic p + p interactions at the CERN Super Proton Synchrotron

Results on two-particle ΔηΔϕ correlations in inelastic p + p interactions at 20, 31, 40, 80, and 158 GeV/c are presented. The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The data show structures which can be attributed mainly to effects of resonance decays, momentum conservation, and quantum statistics. The results are compared with the Epos and UrQMD models.ISSN:1434-6044ISSN:1434-605

Reactive sintering of highly-doped YAG/Nd3+ :YAG/YAG composite ceramics

Multilayer YAG/Nd3+:YAG/YAG composite laser ceramics were obtained by the reactive sintering in vacuum. The effect of the neodymium ion concentration (1–4 at.%) on the formation of defects and optical quality of composite ceramics was studied. It was found that neodymium ions modify densification kinetics during solid-state reactive sintering of the highly-doped Nd3+:YAG ceramics by decreasing shrinkage rate in the temperature range 1320–1350 °C. Differences in phase transformation kinetics during reactive sintering lead to generation of pores at the interface of adjacent layers which decrease the optical homogeneity of fabricated YAG/Nd3+:YAG/YAG composite ceramics. The influence of layered structure on the laser performance of optical ceramics was investigated. It was shown that the ceramics with multilayer composite architecture have slope efficiency almost twice as the single-layer ceramics with the same composition (22% and 12.5%, respectively)

Measurement of the production cross section of 31 GeV/c protons on carbon via beam attenuation in a 90-cm-long target

The production cross section of 30.92 GeV=c protons on carbon is measured by the NA61/SHINE spectrometer at the CERN Super Proton Synchrotron by means of beam attenuation in a copy (replica) of the 90-cm-long target of the T2K neutrino oscillation experiment. The employed method for direct production cross-section estimation minimizes model corrections for elastic and quasielastic interactions. The obtained production cross section is σprod = 227.6 ± 0.8 (stat)+1.9−3.2(sys) − 0.8(mod) mb. It is in agreement with previous NA61/SHINE results obtained with a thin carbon target, while providing improved precision with a total fractional uncertainty of less than 2%. This direct measurement will reduce the uncertainty of the T2K neutrino flux prediction