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Received ; revised manuscript received We have studied pp annihilations at rest in liquid hydrogen into the nal state ! 0 where ! decays to 0. This reaction is dominated by the production of a 0 (980) and contributions from a 2 (1320) and b 0 1 (1235). Upper limits for the production of an axial vector h 0 1 (1380) meson and vector mesons !(1390), !(1600),… (More)
The annihilation channels pp!! 0 , !, ! 0 were studied with the Crystal Barrel detector at LEAR at p-momenta of 600, 1200, and 1940 MeV=c. In most cases angular distributions were measured which allowed a complete J P-analysis using the helicity formalism. The contribution of all relevant initial states could be determined. The maximal contributing angular… (More)
The annihilation pp ! 0 0 was measured for antiprotons stopped in liquid hydrogen (LH 2). This reaction is only allowed from odd angular momentum states of the pp-atom. The resulting branching ratio BR(pp! 0 0) LH2 = (6:93 0:21stat 0:39syst) 10 ?4 , combined with a previous measurement of the branching ratio BR(pp! + ?) 2P in gas from the 2P-state of pp… (More)
For the acceptance of future network-based media services the technical advancement of the man-machine interface is of great importance. The Fraunhofer Institute for Systems and Innovation Research (ISI) in Karlsruhe has conducted an expert survey on different acceptance factors, on the future development of media usage behavior, on network infrastructure… (More)
The 0 momentum dependence of the decay ! + ? 0 has been measured with the Crystal Barrel detector. The analysis is based on 3230 events. The results of this independent measurement are compared to new chiral perturbation theory calculations and previous measurements. The calculation of the amplitude of the decay into three pions has been a longstanding… (More)
The rich variety of nal states in pp annihilation at rest provides a promising environment for meson spec-troscopy with particular emphasis on the search for exotic mesons like glue-balls, hybrids, and multi-quark states. Large statistics on pure neutral nal states and on nal states with charged and neutral particles have been accumulated with the Crystal… (More)
Received ; revised manuscript received We report the observation of nucleon resonances in the reaction pd ! 0 0 n for antiprotons stopping in liquid deuterium. The process pd ! (1232) 0 is identiied and its rate determined to be (2.21 0.24)10 ?5 .