Search

A new procedure is devised to evaluate the proton form-factor at the ¯pp threshold from experimental data on ¯pp→e+e− annihilation at rest. Comparison of the ¯pp→e+e− and¯pp→π+π− processes reveals that annihilation ranges for various channels are ranked in line with quark dynamics.

We fit the scattering lengths in the triplets-,p- andd- waves for the two channels and near theΛ production threshold to the differential cross section and to the polarization P.

A model of the low energyN¯N interaction based on an idea of a quark channel acting as a doorway state is proposed. The salient features of the experimental data are well reproduced.

We predict that production of theK+K- atom inpd ?3He X and similar reactions exhibits a drastic missing mass spectrum due to the interplay withf0(975) resonance. We point out that high precision studies of theK+K- atom may shed a new light on the nature off0(975).

Low energyN¯N scattering is reanalyzed using the new data on annihilation cross-sections from CERN [1], the¯np-absorption measurement from BNL [2] and the annihilation width of the 2p state in antiprotonic hydrogen [3]. Imposing the condition that the imaginary part of the effective range is negative we find low energy scattering parameters which interpolate between the existing ITEP [4] and CERN/Heidelberg [5] values.