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Articles 1 - 4 of 4
Full-Text Articles in Databases and Information Systems
Mass Limit For The Standard Model Higgs Boson With The Full Lep I Aleph Data Sample, Buskulic, D.; Et Al., M. Thulasidas
Mass Limit For The Standard Model Higgs Boson With The Full Lep I Aleph Data Sample, Buskulic, D.; Et Al., M. Thulasidas
Research Collection School Of Computing and Information Systems
The reaction e+e− → HZ∗ is used to search for the standard model Higgs boson in the Hνν and the Hℓ+ℓ− channels. The data sample corresponds to about 4.5 million hadronic Z decays collected by the ALEPH experiment at LEP from 1989 to 1995 at centre-of-mass energies at and around the Z peak. Three candidate events are found in the Hμ+μ− channel, in agreement with the expected background from the electroweak process e+e− ℓ+ℓ−qq. This search results in a 95% C.L. lower limit on the Higgs boson mass of 63.9 GeV/c2.
Search For Cp Violation In The Decay Z → B B̄ G, Buskulic, D.; Et Al., M. Thulasidas
Search For Cp Violation In The Decay Z → B B̄ G, Buskulic, D.; Et Al., M. Thulasidas
Research Collection School Of Computing and Information Systems
About three million hadronic decays of the Z collected by ALEPH in the years 1991 to 1994 are used to search for anomalous CP violation beyond the Standard Model in the decay Z → bb̄g. The study is performed by analyzing angular correlations between the two quarks and the gluon in three-jet events and by measuring the differential two-jet rate. No signal of CP violation is found. For the combinations of anomalous CP violating couplings, ĥb = ĥAbgVh - ĥVbgAb and hb* = √ĥVb2 + ĥAb2, limits of | ĥb | b*
Search For Charginos And Neutralinos With R-Parity Violation At √S = 130 And 136 Gev, Buskulic, D.; Et Al., M. Thulasidas
Search For Charginos And Neutralinos With R-Parity Violation At √S = 130 And 136 Gev, Buskulic, D.; Et Al., M. Thulasidas
Research Collection School Of Computing and Information Systems
Searches for charginos and neutralinos produced in e +e - collisions at centre-of-mass energies of 130 and 136 GeV have been performed under the assumptions that R-parity is not conserved, that the dominant R-parity violating coupling involves only leptonic fields, and that the lifetime of the lightest supersymmetric particle can be neglected. In the 5.7 pb -1 data sample collected by ALEPH, no candidate events were found. As a result, chargino and neutralino masses and couplings are constrained and the domains previously excluded at LEP1 are extended.
Concept Hierarchy Memory Model: A Neural Architecture For Conceptual Knowledge Representation, Learning, And Commonsense Reasoning, Ah-Hwee Tan, Hui-Shin Vivien Soon
Concept Hierarchy Memory Model: A Neural Architecture For Conceptual Knowledge Representation, Learning, And Commonsense Reasoning, Ah-Hwee Tan, Hui-Shin Vivien Soon
Research Collection School Of Computing and Information Systems
This article introduces a neural network based cognitive architecture termed Concept Hierarchy Memory Model (CHMM) for conceptual knowledge representation and commonsense reasoning. CHMM is composed of two subnetworks: a Concept Formation Network (CFN), that acquires concepts based on their sensory representations; and a Concept Hierarchy Network (CHN), that encodes hierarchical relationships between concepts. Based on Adaptive Resonance Associative Map (ARAM), a supervised Adaptive Resonance Theory (ART) model, CHMM provides a systematic treatment for concept formation and organization of a concept hierarchy. Specifically, a concept can be learned by sampling activities across multiple sensory fields. By chunking relations between concepts as …