2,275 research outputs found

    Production and Flow of Neutral Strange Particles in Ni+Ni Collisions at 1.93 AGeV

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    This thesis presents results on the production and the flow of K0K^0 and Λ0\Lambda^0 in Ni+Ni collisions at an energy of 1.93 AGeV. The analyzed data sample of 108^8 central events has been recorded during 12 days using an upgraded data acquisition with a fast online data reduction algorithm. Part of this work was the implementation of this algorithm on a digital signal processor. The slope parameter and yield distributions of the K0K^0 are found to agree with those of previously measured K+K^+. Comparisons to transport model calculations (UrQMD, IQMD) show that none of the models is able to consistently describe those distributions for both, K0K^0 and Λ0\Lambda^0. The integral and the differential directed flow of the K0K^0 are found to agree with that of the K+K^+, supporting the evidence for a repulsive K+K^+N potential. Comparing the directed flow of Λ0\Lambda^0 and protons, no significant difference is found between both for the integral as well as the differential flow. This brings up the issue of the strength of the in-medium Λ\LambdaN potential and its relation to the magnitude of the observed flow. A method to reconstruct Ξ\Xi^- and Σ(1385)\Sigma^-(1385) baryons has been developed and candidates of both particles have been identified. The very small reconstruction efficiency requires confirmation through an experiment with a significantly larger statistics, though

    Search for supersymmetry in events with b-quark jets and missing transverse energy in pp collisions at 7 TeV

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    Results are presented from a search for physics beyond the standard model based on events with large missing transverse energy, at least three jets, and at least one, two, or three b-quark jets. The study is performed using a sample of proton-proton collision data collected at sqrt(s) = 7 TeV with the CMS detector at the LHC in 2011. The integrated luminosity of the sample is 4.98 inverse femtobarns. The observed number of events is found to be consistent with the standard model expectation, which is evaluated using control samples in the data. The results are used to constrain cross sections for the production of supersymmetric particles decaying to b-quark-enriched final states in the context of simplified model spectra.Comment: Submitted to Physical Review

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an