Measurement of the branching ratios of multi-pion final states in annihilation at 1.6 GeV/c

Antiproton-proton partial-wave analysis below 925 MeV/c

“…Since f 2 p is de-termined by the data on elastic scattering pp → pp, and f 2 c by the data on charge-exchange scattering pp → nn, one expects that the correlation between the two is small. Adding f 2 c as the 31st free parameter, we now find f 2 c = 0.0732 (11) , at the pion pole. This result supersedes our previous value from Ref.…”

“…Annihilation is, in principle, a very complicated spin-, isospin-, and energy-dependent multiparticle process. At rest, where kinematically the production of 13 neutral pions is allowed, 5 pions are produced on the average [11], and of the order of 100 two-meson channels contribute significantly [12,13]. In recent years some progress has been made in understanding specific annihilation processes in terms of quark-gluon degrees of freedom.…”