Measurement of the Atmospheric Muon Spectrum from 20 to 3000 GeV

The absolute muon flux between 20 GeV and 3000 GeV is measured with the L3 magnetic muon spectrometer for zenith angles ranging from 0 degree to 58 degree. Due to the large exposure of about 150 m2 sr 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 GeV and 500 GeV, and the average vertical muon charge ratio is found to be 1.285 +- 0.003 (stat.) +- 0.019 (syst.).Comment: Total 32 pages, 9Figure

Search for composite and exotic fermions at LEP 2

A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio

Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP

Promptly decaying lightest neutralinos and long-lived staus are searched for in the context of light gravitino scenarios. It is assumed that the stau is the next to lightest supersymmetric particle (NLSP) and that the lightest neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of the production of these particles is found. Hence, lower mass limits for both kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is found to be greater than 71.5 GeV/c^2. In the search for long-lived stau, masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10 to 150 \eVcc . Combining this search with the searches for stable heavy leptons and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc may be set for the stau mas

Long-range Angular Correlations On The Near And Away Side In P-pb Collisions At √snn=5.02 Tev

7191/Mar294

Diffusion de la lumière par les monocristaux de tellurure de zinc

We report studies of the phonon spectrum of zinc telluride crystals deduced from measurements of the first-order and second-order light scattering (under laser irradiation). The contribution of the Γ, X and L-point phonons to the two-phonon scattering mechanisms has been evaluated by a group theoretical analysis. Using this analysis we have interpreted all lines of the first- and second-order scattering spectra. The values found for the phonon frequencies at the zone center and zone edges agree well with those given by theory. The theoretical and experimental phonon densities are in good agreement only in the range of small energies.Par des mesures de diffusion de la lumière au premier et au second ordre (sous irradiation laser), nous avons étudié le spectre de phonons de cristaux de tellurure de zinc. Une analyse fondée sur la théorie des groupes a permis d'évaluer la contribution des phonons aux points Γ, X et L aux mécanismes de diffusion à deux phonons. Sur la base de cette analyse ont été interprétées toutes les raies des spectres de diffusion de premier et de second ordre. Les valeurs trouvées pour les fréquences des phonons au centre et en bord de zone de Brillouin correspondent bien à celles données par la théorie. Les densités de phonons théoriques et expérimentales sont en bon accord seulement dans le domaine des petites énergies

A search for flaring very-high-energy cosmic gamma-ray sources with the L3+C muon spectrometer

The L3+C muon detector at the CERN electron-positron collider, LEP, is used for the detection of very-high-energy cosmic gamma-ray sources through the observation of muons of energies above 20, 30, 50 and 100 GeV. Daily or monthly excesses in the rate of single-muon events pointing to some particular direction in the sky are searched for. The periods from mid July to November 1999, and April to November 2000 are considered. Special attention is also given to a selection of known gamma-ray sources. No statistically significant excess is observed for any direction or any particular source. (c) 2006 Elsevier B.V. All rights reserved

The solar flare of the 14th of July 2000 (L3+C detector results).

Contains fulltext : 35185.pdf (publisher's version ) (Open Access

SEARCH FOR THE t AND b-prime QUARKS IN HADRONIC DECAYS OF THE Z0 BOSON

We present a search for the third generation up type quark t and a possible fourth down type quark b' in hadronic Z0 decays observed in DELPHI at the LEP collider. For any scenario with a decay through the charged current or into a charged Higgs with a mass at least 6 GeV/c2 below the t and 3 GeVc2 below the b' mass, we set a lower limit for the t quark mass at 44.0 GeV/c2 and for the b' mass at 44.5 GeV/c2. For specific scenarios the mass limits are slightly higher, e.g. for charged current decays the limits are 44.5 and 45.0 GeV/c2 respectively, where all limits are given at a 95% confidence level. © 1990.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe