IEAP - Institute of Experimental and Applied Physics CTU - Czech Technical University in Prague
Česky English
IEAP - Institute of Experimental and Applied Physics CTU - Czech Technical University in Prague
CTU - Czech Technical University in Prague
Seminars  > eta-mesic nuclei: the pd -> 3He eta and related reactions
eta-mesic nuclei: the pd -> 3He eta and related reactions

Date
29.1.2008 14:00
Speaker
Colin Wilkin Emeritus Professor of Physics, Physics & Astronomy Dept., University College London, UK


Abstract

The interaction of the eta-meson with both protons and neutrons is strongly attractive due to the presence of the N*(1535) resonance and this might lead to the eta forming a bound state with some nuclei. Experimental searches for signals from medium nuclei in production reactions below the eta threshold, including a new one from COSY-Jülich, have largely proved negative. However a bound state can also influence data just above the threshold and the comparison of the pd -> 3He eta and dd -> 4He eta low energy cross sections suggests that is “bound” and that is just on the limit of being bound. Recent high-precision measurements of the total cross section for dp -> 3He eta at both COSY-11 and COSY-ANKE show that is bound or unbound by less than 1 MeV. Moreover, the change of the angular dependence with energy can only be understood as being due to the phase variation associated with such a pole. The prospects for the study of this new form of matter in other ways are discussed.
Search
10th Anniversary of IEAP