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No abstract available

[en] The neutrino interactions with production of three or even four leptons raised the question of the 'purity' of the neutrino beam. Other species of neutrino that the electron-neutrino or muon-neutrino were searched. An experiment performed at CERN with using the 400 GeV proton accelerator seems to have evidenced a nonconventional source of neutrinos that means of original parent particles. The experiment consisted in suppressing the parents K and π mesons, of usual neutrinos by beam dump

[en] We present in this paper the current status of searches for leptoquarks at D0. These results include the use of next leading order theoretical predictions for the cross section for pair production of leptoquarks at hadron colliders. We also present a new optimized analysis for first generation leptoquarks with significant increase in sensitivity relative to earlier searches using DO data. The mass limits derived from this first generation leptoquark search are relevant to the recently reported high mass events at HERA

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[en] Using the idea about neutrino condensation in the gravitational field of collapsing matter, the authors consider the annihilation of heavy relic neutrinos in the galaxy, which results in the generation of cosmic rays. Comparison of the predicted cosmic ray flux with the experimental data rules out a possibility of existence of heavy neutrinos in the mass range from 60 to 115 GeV. 10 refs., 4 figs

[en] New constraints on the cosmological gravitino abundance are discussed. These constraints lead to some rather stringent constraints on the structure of the theories in which the primordial gravitino problem can be solved. (orig.)

[en] In a compelling and entertaining manner, the author suggests that the discovery theory in the world of elementary particles is not useful because experimental facts can be controverted and deconstructed and because nature does not reverse itself through data or through a choice between competing theories. What the author does suggest is that physicists understand the world particle physics as a process of construction rather than discovering that physicists look upon themselves as active creators of their world, searching, experimenting, reviewing and interpreting their findings within the contexts they have constructed

[en] We study gaugino mass generation in the context of semi-direct gauge mediation models, where the messengers are charged under both the hidden sector and the standard model gauge groups while they do not play important roles in dynamical supersymmetry breaking. We clarify the cancellation of the leading contributions of the supersymmetry breaking effects to the gaugino mass in this class of models in terms of the macroscopic effective theory of the hidden sector dynamics. We also consider how to retrofit the model so that we obtain the non-vanishing leading contribution to the gaugino mass.

[en] Currently, there is no evidence that dark matter is actually composed of WIMPs so it is important to consider viable alternatives to this scenario. In this talk, I examine two alternative frameworks that have been recently proposed. They both allow to account for the dark matter but give rise to a very different phenomenology. The viable parameter space and the detection signatures of dark matter, in particular, are strongly modified. Some implications of these alternative frameworks are discussed.