The Role of a 1 (1260) in π − p → a 1 − (1260) p and π − p → π − ρ 0 p Reactions Near Threshold

RELEVANCE OF NUCLEON SPIN IN AMPLITUDE ANALYSIS OF REACTIONS π−p → ππn AND π−p → ηηn

The measurements of reactions πp → ππn and πn → ππp on polarized targets at CERN found a strong dependence of pion production amplitudes on nucleon spin. Analyses of recent measurements of πp → ππn reaction on unpolarized targets by GAMS Collaboration at 38 GeV/c and BNL E852 Collaboration at 18 GeV/c use the assumption that pion production amplitudes do not depend on nucleon spin, in conflict ...

Se p 19 99 Production of the π − , π 0 in the reaction d ( e , pp ) e ′ π − π 0

Recently, the differential yield and target asymmetry of the reaction d(e, pp)eπ on the tensor polarized deuterium target have been presented in [1, 2], where the experimental procedure and basic assumption were described. A precise treatment of this reaction needs to investigate the reaction channels with an additional neutral pion production as a background to the leading reaction of a single...

Se p 20 07 Physics of η ′ → π + π − η and η ′ → π + π − π 0 decays

The article describes experimental status of the η ′ → π+π−η and η ′ → π+π−π0 decays. A theoretical framework used for description of the decays mechanism is also reviewed. The possibilities for the measurements with WASA-at-COSY are mentioned.

Se p 19 97 Soft Binary Processes , NJL Model and Absolute Values of the Amplitudes of Reactions π − p → π 0 n and π −

AMPLITUDE ANALYSIS OF REACTIONS π−p → ηπ−p AND π−p → ηπn MEASURED ON POLARIZED TARGET AND THE EXOTIC 1−+ MESON

Recently several experimental groups analysed data on πp → ηπp and πp → ηπn reactions with exotic 1 P -wave and found a conflicting evidence for an exotic meson I = 11(1405). High statistics data on these reactions are presently analysed by BNL E852 Collaboration. All these analyses are based on the crucial assumption that the production amplitudes do not depend on nucleon spin. This assumption...