We report on measurements of the total cross section for ee → γγ for center-ofmass energies between 57.4 and 59.5 GeV, using the AMY detector at the TRISTAN collider. We set new limits on the production of a possible new s-channel resonance decaying into photon pairs.

Data show that τB± ∼ τB0 , but τD± ∼ 2τD0 . The naive interpretation which attributes τD± ∼ 2τD0 to a destructive interference between two quark diagrams for D decays, definitely fails in the B-case. We investigate Close and Lipkin’s suggestion that the phases for producing radially excited states ψ2s in the decay products of B-mesons can possess an opposite sign to the integrals for ψ1s decay ...

The first fermi in a high energy nuclear collision. At very high energies, weak coupling, non–perturbative methods can be used to study classical gluon production in nuclear collisions. One observes in numerical simulations that after an initial " formation " time, the produced partons are on shell, and their subsequent evolution can be studied using transport theory. At the initial formation t...

In this paper we propose some new solutions to the full information mixed H 2 =H 1 state feedback problem: the H 2 norm of the closed-loop system is minimized over a class of linearly combined state feedback laws that satisfy the speciied H 1 bound. Such mixed linearly combined controllers yield smaller closed-loop H 2 norms than those obtained by using the central solutions of the H 1 problem....

By using the Szemerédi Regularity Lemma [10], Alon and Sudakov [1] recently extended the classical Andrásfai-Erdős-Sós theorem [2] to cover general graphs. We prove, without using the Regularity Lemma, that the following stronger statement is true. Given any (r+1)-partite graph H whose smallest part has t vertices, there exists a constant C such that for any given ε > 0 and sufficiently large n...

Due to its distributed nature, a cyber-physical system is vulnerable to various faults, including sensory integrity attacks. Such faults need to be accounted for in the design of a state estimator. In this paper, we consider sparse sensor faults, in which a small unknown group of sensors can be compromised. We first show a necessary condition that allows the state to be estimated in the presenc...

We review some existing results on H2 and H1 estimation and explore possible connections between the optimal algorithms. For instance, in order to relate the H2 optimal Kalman lter to the H1 lters we show that, with special choices of the covariance matrices, the Kalman lter is H1 optimal. Moreover, by studying the matrix operator relating the estimation errors and the disturbances, we obtain s...