122322573
New states as observed by the Crystal Barrel experiment
Abstract The Crystal Barrel Detector has been in operation since October 1989. Results on the analysis of the annihilation of protonium at rest into three pseudoscalars is presented. The π 0 π 0 π 0 final state confirms the existence of ƒ 2 (1520)→π 0 π 0 . In the ηη system of the π 0 ηη final state an isoscalar J PC = 0 ++ resonance with a mass of 1560 MeV/c 2 and a width of 245 MeV/c 2 is observed. The identification with ƒ 0 (1590) is doubtful since the ηη' decay is not observed with the corresponding strength. Our analysis yields an upper limit for the relative branching ratio BR(ƒ 0 (1560)→ηη') BR(ƒ 0 (1560)→ηη) .
122284184
Parametric optimization with evolutionary strategies in particle physics
Abstract Evolutionary strategies provide a generic means to find optimum solutions for large-scale numerical problems. The EVA library, an implementation of parallel Evolutionary Algorithms, adds the possibility to run the optimization in parallel on devices ranging from multi-processor machines over clusters to the world wide grid. This paper discusses the application of the EVA library to two distinct computationally expensive physics problems—the optimization of particle signals in histograms and the minimization procedure involved in analysing Dalitz plots.
6557807
Global Existence for the Spherically Symmetric Einstein–Vlasov System with Outgoing Matter
We prove a new global existence result for the asymptotically flat, spherically symmetric Einstein–Vlasov system which describes in the framework of general relativity an ensemble of particles which interact by gravity. The data are such that initially all the particles are moving radially outward and that this property can be bootstrapped. The resulting non-vacuum spacetime is future geodesically complete.
16238417
Gravitational collapse and the formation of black holes for the spherically symmetric Einstein-Vlasov system
We review results on the spherically symmetric, asymptotically flat Einstein-Vlasov system. We focus on a recent result where we found explicit conditions on the initial data which guarantee the formation of a black hole in the evolution. Among these data there are data such that the corresponding solutions exist globally in Schwarzschild coordinates. We put these results into a more general context, and we include arguments which show that the spacetimes we obtain satisfy the weak cosmic censorship conjecture and contain a black hole in the sense of suitable mathematical definitions of these concepts which are available in the literature.
7205471
Multipole Radiation in a Collisionless Gas Coupled to Electromagnetism or Scalar Gravitation
We consider the relativistic Vlasov-Maxwell and Vlasov-Nordström systems which describe large particle ensembles interacting by either electromagnetic fields or a relativistic scalar gravity model. For both systems we derive a radiation formula analogous to the Einstein quadrupole formula in general relativity.