Showing papers by "S. O. Holmgren published in 2007"
TL;DR: In this paper, the DELPHI detector at LEP has been used to measure multi-muon bundles originating from cosmic ray interactions with air and the cosmic events were recorded in ''parasitic mode'' between individual e+e- interactions and the total live time of this data taking is equivalent to 1.6x10^6 seconds.
50 citations
TL;DR: In this paper, the results of the investigation of colour reconnection e.g. in fully hadronic decays of W pairs in DELPHI at LEP are presented and two complementary analyses are performed, studying the particle.
Abstract: In the reaction e(+)e(-) -> WW -> (q(1) (q) over bar (2))(q(3)(q) over bar (4)) the usual hadronization models treat the colour singlets q(1)(q) over bar (2) and q(3)(q) over bar (4) coming from two W bosons independently. However, since the. nal state partons may coexist in space and time, cross-talk between the two evolving hadronic systems may be possible during fragmentation through soft gluon exchange. This e. ect is known as colour reconnection. In this article the results of the investigation of colour reconnection e. ects in fully hadronic decays of W pairs in DELPHI at LEP are presented. Two complementary analyses were performed, studying the particle. ow between jets and W mass estimators, with negligible correlation between them, and the results were combined and compared to models. In the framework of the SK-I model, the value for its. parameter most compatible with the data was found to be: (SK)-S-kappa-I = 2.2(-1.3) (+2.5) corresponding to the probability of reconnection P-reco to be in the range 0.31 < P-reco < 0.68 at 68% confidence level with its best value at 0.52.
20 citations
TL;DR: In this paper, the DELPHI detector was used to study neutral triple-gauge-boson couplings ZZZ, ZZγ and Zγγ with data at energies between 183 and 208 GeV.
Abstract: Neutral triple-gauge-boson couplings ZZZ, ZZγ and Zγγ have been studied with the DELPHI detector using data at energies between 183 and 208 GeV. Limits are derived on these couplings from an analysis of the reactions e+e-→Zγ, using data from the final states γff, with f=q or ν, from e+e-→ZZ, using data from the four-fermion final states qqqq, qqμ+μ-, qqe+e-, qqνν, μ+μ-νν and e+e-νν, and from e+e-→Zγ*, in which the final state γ is off mass-shell, using data from the four-fermion final states qqe+e- and qqμ+μ-. No evidence for the presence of such couplings is observed, in agreement with the predictions of the Standard Model.
19 citations
12 Dec 2007
TL;DR: The production of scintillator tiles for the ATLAS Tile Calorimeter is described in this article, including properties of the tiles including light yield, uniformity and stability.
Abstract: The production of the scintillator tiles for the ATLAS Tile Calorimeter is presented. In addition to the manufacture and production, the properties of the tiles will be presented including light yield, uniformity and stability.
12 citations
TL;DR: In this paper, a search for pentaquarks is described using the DELPHI detector at LEP, characterized by powerful particle identification sub-systems crucial in the separation of the signal from the background for these states.
6 citations