Data accumulated recently for the exclusive measurement of the pp $ \rightarrow$ pp $ \pi^{+}_{}$ $ \pi^{-}_{}$ reaction at a beam energy of 0.793GeV using the COSY-TOF spectrometer have been analyzed with respect to possible events from the pp $ \rightarrow$ nn $ \pi^{+}_{}$ $ \pi^{+}_{}$ reaction channel. The latter is expected to be the only $ \pi$ $ \pi$ production channel, which contains no major contributions from resonance excitation close to threshold and hence should be a good testing ground for chiral dynamics in the $ \pi$ $ \pi$ production process. No single event has been found, which meets all conditions for being a candidate for the pp $ \rightarrow$ nn $ \pi^{+}_{}$ $ \pi^{+}_{}$ reaction. This gives an upper limit for the cross-section of 0.16μb (90% C.L.), which is more than an order of magnitude smaller than the cross-sections of the other two-pion production channels at the same incident energy.

On the Production of pi+ pi+ Pairs in pp Collisions at 0.8- GeV

MARCELLO, Simonetta;
2009-01-01

Abstract

Data accumulated recently for the exclusive measurement of the pp $ \rightarrow$ pp $ \pi^{+}_{}$ $ \pi^{-}_{}$ reaction at a beam energy of 0.793GeV using the COSY-TOF spectrometer have been analyzed with respect to possible events from the pp $ \rightarrow$ nn $ \pi^{+}_{}$ $ \pi^{+}_{}$ reaction channel. The latter is expected to be the only $ \pi$ $ \pi$ production channel, which contains no major contributions from resonance excitation close to threshold and hence should be a good testing ground for chiral dynamics in the $ \pi$ $ \pi$ production process. No single event has been found, which meets all conditions for being a candidate for the pp $ \rightarrow$ nn $ \pi^{+}_{}$ $ \pi^{+}_{}$ reaction. This gives an upper limit for the cross-section of 0.16μb (90% C.L.), which is more than an order of magnitude smaller than the cross-sections of the other two-pion production channels at the same incident energy.
2009
42(2)
159
161
http://arxiv.org/abs/arXiv:0906.3095
nucleon-nucleon interactions; pion production; hadrons; baryon resonances; chiral dynamics; inelastic proton scattering
S. Abd El-Samad; R. Bilger; K. -Th. Brinkmann; H. Clement; M. Dietrich; E. Doroshkevich; S. Dshemuchadse; K. Ehrhardt; A. Erhardt; W. Eyrich; A. Filip...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/77123
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