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Brany Liouville inflation
(2004)New Journal of PhysicsWe present a specific model for cosmological inflation driven by the Liouville field in a non-critical supersymmetric string framework, in which the departure from criticality is due to open strings stretched between two moving Type-II 5-branes. We use WMAP and other data on fluctuations in the cosmic microwave background to fix the parameters of the model, such as the relative separation and velocity of the 5-branes, respecting also the ...Journal Article -
Measurement of the cross section of W-boson pair production at LEP
(2004)Physics Letters BThe cross section of W-boson pair-production is measured with the L3 detector at LEP. In a data sample corresponding to a total luminosity of 629.4 pb−1, collected at centre-of-mass energies ranging from 189 to 209 GeV, 9834 four-fermion events with W bosons decaying into hadrons or leptons are selected. The total cross section is measured with a precision of 1.4% and agrees with the Standard Model expectation. Assuming charged-lepton ...Journal Article -
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Measurement of the atmospheric muon spectrum from 20 to 3000 GeV
(2004)Physics Letters BThe absolute muon flux between 20 and 3000 GeV is measured with the L3 magnetic muon spectrometer for zenith angles ranging from 0°to 58°. Due to the large exposure of about 150 m2sr d, and the excellent momentum resolution of the L3 muon chambers, a precision of 2.3% at 150 GeV in the vertical direction is achieved.The ratio of positive to negative muons is studied between 20 and 500 GeV, and the average vertical muon charge ratio is ...Journal Article -
Measurement of exclusive ρ+ρ- production in high-Q2 two-photon collisions at LEP
(2004)Physics Letters BJournal Article -
Quantum optics with single quantum dot devices
(2004)New Journal of PhysicsA single radiative transition in a single-quantum emitter results in the emission of a single photon. Single quantum dots are single-quantum emitters with all the requirements to generate single photons at visible and near-infrared wavelengths. It is also possible to generate more than single photons with single quantum dots. In this paper we show that single quantum dots can be used to generate non-classical states of light, from single ...Journal Article -
Search for anomalous couplings in the Higgs sector at LEP
(2004)Physics Letters BAnomalous couplings of the Higgs boson are searched for through the processes e+e-→Hγ, e+e -→e+e-H and e+e -→HZ. The mass range 70 GeV<mH<190 GeV is explored using 602 pb-1 of integrated luminosity collected with the L3 detector at LEP at centre-of-mass energies s=189-209 GeV. The Higgs decay channels H→ff̄, H→γγ, H→Zγ and H→WW(*) are considered and no evidence is found for anomalous Higgs production or decay. Limits on the anomalous ...Journal Article -
Single- and multi-photon events with missing energy in e+e- collisions at LEP
(2004)Physics Letters BSingle- and multi-photon events with missing energy are selected in 619 pb−1 of data collected by the L3 detector at LEP at centre-of-mass energies between 189 and 209 GeV. The cross sections of the process e+e−→ν ̄νγ (γ ) are found to be in agreement with the Standard Model expectations, and the number of light neutrino species is determined, including lower energy data, to be Nν=2.98±0.05±0.04. Selection results are given in the form ...Journal Article -
Z ' studies at the LHC
(2004)Physics Letters BWe reanalyse the potential of the LHC to discover new Z′ gauge bosons and to discriminate between various theoretical models. Using a fast LHC detector simulation, we have investigated how well the characteristics of Z′ bosons from different models can be measured. For this analysis we have combined the information coming from the cross section measurement, which provides also the Z′ mass and total width, the forward-backward charge ...Journal Article -
Muon pair production in ep collisions at HERA
(2004)Physics Letters BCross sections for the production of two isolated muons up to high di-muon masses are measured in ep collisions at HERA with the H1 detector in a data sample corresponding to an integrated luminosity of 71 pb-1 at a centre of mass energy of √s=319 GeV. The results are in good agreement with Standard Model predictions, the dominant process being photon-photon interactions. Additional muons or electrons are searched for in events with two ...Journal Article