Technical University of Dortmund

About: Technical University of Dortmund is a education organization based out in Dortmund, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Context (language use) & Large Hadron Collider. The organization has 13028 authors who have published 27666 publications receiving 615557 citations. The organization is also known as: Dortmund University & University of Dortmund.

Measurements of e+e-→K+K-η, K+K-π0, and Ks0K±π cross sections using initial state radiation events

Abstract: This paper reports measurements of processes: e+e-→γKS0K±π∓, e+e-→γK+K-π0, e+e-→γϕη, and e+e-→γϕπ0. The initial-state radiated photon allows to cover the hadronic final state in the energy range from thresholds up to ≈4.6 GeV. The overall size of the data sample analyzed is 232 fb-1, collected by the BABAR detector running at the PEP-II e+e- storage ring. From the Dalitz plot analysis of the KS0K±π∓ final state, moduli, and relative phase of the isoscalar and the isovector components of the e+e-→KK*(892) cross section are determined. Parameters of ϕ and ρ recurrences are also measured, using a global fitting procedure which exploits the interconnection among amplitudes, moduli, and phases of the e+e-→KS0K±π∓, K+K-π0, ϕη final states. The cross section for the OZI-forbidden process e+e-→ϕπ0, and the J/ψ branching fractions to KK*(892) and K+K-η are also measured.

More benefits of semileptonic rare B decays at low recoil: CP violation

Abstract: We present a systematic analysis of the angular distribution of \( \overline B \to {\overline K^*}\left( { \to \overline K \pi } \right){l^{+} }{l^{-} } \) decays with l = e, μ in the low recoil region (i.e. at high dileptonin variant masses of the order of the mass of the b-quark) to account model-independently for CP violation beyond the Standard Model, working to next-to-leading order QCD. From the employed heavy quark effective theory framework we identify the key CP observables with reduced hadronic uncertainties. Since some of the CP asymmetries are CP-odd they can be measured without B -flavour tagging. This is particularly beneficial for \( {\overline B_s},{B_s} \to \phi \left( { \to {K^{+} }{K^{-} }} \right){l^{+} }{l^{-} } \) decays, which are not self-tagging, and we work out the corresponding time-integrated CP asymmetries. Presently available experimental constraints allow the proposed CP asymmetries to be sizeable, up to values of the order ~ 0.2, while the corresponding Standard Model values receive a strong parametric suppression at the level of \( \mathcal{O}\left( {{{10}^{ - 4}}} \right) \). Furthermore, we work out the allowed ranges of the short-distance (Wilson) coefficients \( {\mathcal{C}_{9,10}} \) in the presence of CP violation beyond the Standard Model but no further Dirac structures. We find the \( {\overline B_s} \to {\mu^{+} }{\mu^{-} } \) branching ratio to be below 10 × 10−9 (at 95% CL). Possibilities to check the performance of the theoretical low recoil framework are pointed out.

Introduction to Active Automata Learning from a Practical Perspective

Abstract: In this chapter we give an introduction to active learning of Mealy machines, an automata model particularly suited for modeling the behavior of realistic reactive systems. Active learning is characterized by its alternation of an exploration phase and a testing phase. During exploration phases so-called membership queries are used to construct hypothesis models of a system under learning. In testing phases so-called equivalence queries are used to compare respective hypothesis models to the actual system. These two phases are iterated until a valid model of the target system is produced.

Runtime Analysis of a Simple Ant Colony Optimization Algorithm

Abstract: Ant Colony Optimization (ACO) has become quite popular in recent years. In contrast to many successful applications, the theoretical foundation of this randomized search heuristic is rather weak. Building up such a theory is demanded to understand how these heuristics work as well as to come up with better algorithms for certain problems. Up to now, only convergence results have been achieved showing that optimal solutions can be obtained in finite time. We present the first runtime analysis of an ACO algorithm, which transfers many rigorous results with respect to the runtime of a simple evolutionary algorithm to our algorithm. Moreover, we examine the choice of the evaporation factor, a crucial parameter in ACO algorithms, in detail. By deriving new lower bounds on the tails of sums of independent Poisson trials, we determine the effect of the evaporation factor almost completely and prove a phase transition from exponential to polynomial runtime.