Production of the 1S0 diproton in the pp -> pp pi0 reaction at 0.8 GeV

Abstract

The pp -> pp pi0 differential cross section has been measured with the ANKE spectrometer at COSY-Juelich for pion cms angles between 0 and 15.4 degrees at a proton beam energy of 0.8 GeV. The selection of diproton pairs with an excitation energy E_{pp} < 3 MeV ensures that the final pp system is dominantly in the spin-singlet 1S0 state. The kinematics are therefore very similar to those of pp -> d pi+ but with different spin and isospin transitions. The results will thus provide a crucial extra test of pion production models in nucleon-nucleon collisions. The cross sections, which are over two orders of magnitude smaller than those of pp -> d pi+, show a forward dip, even stronger than that seen at lower energies. This behaviour is well reproduced in a theoretical model that includes P-wave Delta-N states.

arXiv comment10 pages, 5 eps figures, prepared using elsart.cls

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• Spin Physics from COSY to FAIR
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Cited by in corpus (14)

• Single-Pion Production in pp Collisions at =.95 GeV/c (I)
• Observation of an ABC effect in proton-proton collisions
• Energy dependence of forward 1S0 diproton production in the pp -> pp pi0 reaction
• Observation of inverse diproton photodisintegration at intermediate energies
• Differential cross section and analysing power of the quasi-free pn -> {pp}_s pi- reaction at 353 MeV
• Differential cross section and analysing power of the pp -> {pp\}_s pi0 reaction at 353 MeV
• Predictions of striking energy and angular dependence in pp --> (pp)_S-wave pi^0 production
• Energy dependence of hard bremsstrahlung production in proton-proton collisions in the Delta(1232) region
• Scalar-isovector K K-bar production close to threshold
• Single-Pion Production in pp Collisions at 0.95 GeV/c (II)
• Dynamics of ${}^1{S}_0$ diproton formation in the $pd\to \{pp{\}}_{s}n$ and $pN\to \{pp{\}}_s\pi$ reactions in the GeV region
• Anisotropy in the pion angular distribution of the reaction pp -> pp pi0 at 400 MeV
• Resonant behavior of the $pp\to \{pp{\}}_s{\pi }^0$ reaction at the energy $\sqrt{s}$ = 2.65 GeV
• A possible evidence of observation of two mixed phases in nuclear collisions