tralino production via t-channel exchange, which is of OCR Output a forward-backward tracking chamber, a high resolu assumed to be heavier than 45 so that the decays X' -+ Xh, XAand X' -» Xfff°°r esults are interpreted in the MSSM context as well as h° or A0, and charginos, gi are sufficiently large [5] hadronic Z decays collected in 1991 ---1993. TheseWe assume that the masses of the lightest higgs, search for neutralinos, which are based on 1.8 X 10 involving ·r leptons.We present the event selection and results of our small branching fraction, we did not investigate decays mass to charged leptons and quarks of charge -%e. with mx less than 18 GeV, if either tanB > 2 or the gluino mass mz-> 100 GeV.In the framework ofthe Minimal Supersymmetric Standard Model, we exclude a lightest X used to set upper limits of a few times 10'° on the branching ratios Z -• XX' and Z -» X'X'.hadronic Z decays collected with the L3 detector at LEP. Absence of any signal has been neutralino, X, and either a photon or a fcrmion pair. This analysis is based on 1.8 x 106XX' and e+e" -> X' X' , where the next-to lightest neutralino, X', decays into the lightest A search for neutralinos produced in Z decays has been performed via the reactions e+e" --> ABSTRACT L3 Collaboration

Deviations from expectations have been claimed for solar, atmospheric and high energy prompt neutrinos from charm decay. This information, supplemented only by the existing very good upper limits for oscillations of the $\nu_{\mu}$ at accelerator energies, is used as input to a phenomenological three-flavour analysis of neutrino mixing. The solution found is unique and completely determines the mass eigenstates as well as the mixing matrix relating mass and flavour eigenstates. Assuming the mass eigenstates to follow the hierarchy $m_{1} \ll m_{2} \ll m_{3}$, their values are found to be $m_{1} \ll 10^{-2}$ eV, $m_{2} = (0.18 \pm 0.06)$ eV, $m_{3} = (19.4 \pm 0.7)$ eV. These masses are in agreement with the leptonic quadratic hierarchy of the see-saw model and large enough to render energy-independent any oscillation-induced phenomenon in solar neutrino physics observable on Earth. This possibility is not excluded by the present knowledge of solar neutrino physics. The mixing angles are determined to be $\theta_{12} = 0.55 \pm 0.08$, $\theta_{13} = 0.38 \pm 0.06$, $\theta_{23} < 0.03$. Small values of $\theta_{23}$ are typical of any solution in which $m_{3}$ lies in the cosmological interesting region. The solution found is not in serious contradiction with any of the present limits to the existence of neutrino oscillations. The most relevant implications in particle physics, astrophysics and cosmology are discussed.Comment: 17 pages, 3 figures, to be published in Astroparticle Physic

Diode lasers offer a lightweight, rugged, and economic alternative to other types of laser source, but they often do not provide long-term stability and spectral purity of emission. We have developed a stabilized, near-infrared diode laser source that is capable of as much as 20 mW of single-mode output power for the effective replacement of a He-Ne laser in the path difference measuring system of a high-resolution (1.25-m maximum path difference) Fourier transform spectrometer. Laser characterization has been performed both in laboratory measurements and in flight tests, resulting in a relative frequency stability of better than 10(-6) on a 6-h flight.

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