Resonances in (pp)over-bar -> eta pi(+)pi(-)pi(+)pi(-) at rest

Data on (p) over barp --> eta pi (+) pi (-) pi (+) pi (-)at rest show two r esonant processes: (a) f(0)(1370)eta, f(0)(1370) --> sigma sigma and pp, (b ) eta (1440)sigma, eta (1440) --> eta pi (+) pi (-). The branching ratio BR [f(0)(1370) --> pp]/BR[f(0)(1370) --> sigma sigma] = 0.98 +/- 0.25 in the m ass range available here. Using data on (p) over barp --> eta pi (0) pi (0) , the ratio Gamma (4 pi) / Gamma (2 pi) greater than or equal to 5 for f(0) (1370). The effects of the strongly s-depmdent width of f(0)(1370) are disc ussed in some derail. The eta (1440) is observed decaying to eta sigma and a(0)(980)pi, with stro ng destructive interference between them. In its decay to a(0)(980)pi, a na rrow peak appears in the eta pi mass spectrum, but 30- 50 MeV above that us ually attributed to a(0)(980) and significantly above the KK threshold. Thi s effect. is explained naturally by a two-step process: eta (1440) --> K*(8 90)K followed by rescattering of the two kaons through a(0)(980) to eta pi above the K K threshold. (C) 2001 Elsevier Science B.V. All rights reserved .