Study of the pp ---> np pi_s16 reaction at 1.25-GeV with HADES
Keywords
p p: inelastic scattering, pi_s16: hadroproduction, angular distribution, Dalitz plot, differential cross section: mass dependence, Delta(1232), nucleon resonance, magnetic spectrometer, Darmstadt SIS, p p --> n p pi_s16, p p --> 2p pi0, 1.25 GeV-cms
Abstract
In pp collisions at 1.25 GeV kinetic energy, the HADES collaboration aimed at investigating the di-electron production related to $Delta$ (1232) Dalitz decay ($Delta^_s16 to pe^_s16e^-$). In order to constrain the models predicting the cross section and the production mechanisms of $Delta$ resonance, the hadronic channels have been measured and studied in parallel to the leptonic channels. The analyses of $ppto nppi^_s16$ and $ppto pppi^0$ channels and the comparison to simulations are presented in this contribution, in particular the angular distributions being sensitive to $Delta$ production and decay. The accurate acceptance corrections have been performed as well, which could be tested in all the phase space region thanks to the high statistic data. These analyses result in an overall agreement with the one-$pi$ exchange model and previous data.
