S. O. Holmgren

Inclusive particle production in 400 GeV/c pp-interactions

AbstractWe report on a study of inclusive particle production in pp-interactions at 400 GeV/c. The data are based on 472 K reconstructed events recorded in the NA 27 experiment using the LEBC-EHS facility at CERN. The production cross sections are determined of pseudo scalar (π±,0, η andK±), scalar (f0(975)), vector (ρ±,0(770), ω(783), ϕ(1020),K*0(892), and

The European Hybrid Spectrometer - a facility to study multihadron events produced in high energy interactions

\bar K^{ * 0}

W\to\ell\nu

(892)), and tensorf0 mesons, of protons and antiprotons, and theΔ++,+,0(1232), and Λ(1520) baryon resonances in the forward hemisphere of the center of mass system, as well as longitudinal and transverse momentum distributions. The results are compared with predictions of the FRITIOF model and with other experimental data.

and

Abstract Various general features of inelastic proton-proton collisions at 19 GeV/ c , as they appear in a 2 m hydrogen bubble chamber, have been studied, and results concerning particle multiplicities in the final states and single-particle momentum spectra are presented. It is found that the average numbers of produced pions are 〈 n π − 〉 = 1.0, 〈 n π O 〉 = 1.4 ± 0.1, 〈 n π + 〉 = 1.6. The variation of the average c.m. momentum of π − with the number of produced pions is studied, and the fraction of the c.m. energy available for particle production, which is carried away by the pions, is estimated to be 52%.

Z/gamma^\ast\to\ell\ell

Abstract The European Hybrid Spectrometer is described in its preliminary version for the NA16 charm experiment. The performance of the small hydrogen bubble chamber LEBC and the detectors of the spectrometer is discussed. In particular the combination of the bubble chamber information with the spectrometer data is described in detail. The track reconstruction efficiency is 90%. The precision with which vertices seen in the bubble chamber are reconstructed is around 10 μm and the two track resolution is 40 μm. Therefore very complex event configurations, in particular charm particle decays, can be reconstructed correctly.

Production Cross Sections in Proton-Proton Collisions at

First measurements of the W → ℓν and Z/γ*→ ℓℓ (ℓ = e, μ) production cross sections in proton-proton collisions at

\sqrt{s}=7

\sqrt {s} = 7\;{\text{TeV}}

TeV with the ATLAS Detector

are presented using data recorded by the ATLAS experiment at the LHC. The results are based on 2250 W → ℓν and 179 Z/γ* → ℓℓ candidate events selected from a data set corresponding to an integrated luminosity of approximately 320 nb. The measured total W and Z/γ∗-boson production cross sections times the respective leptonic branching ratios for the combined electron and muon channels are