Analysis of New Results For ScalarIsoscalar pipi Phase Shifts.pdfVIP

Analysis of New Results For Scalar-Isoscalar ππ Phase Shifts ∗ ∗ † R. Kami´nski , L. Le´sniak and B. Loiseau 7 ∗ 9 Department of Theoretical Physics, H. Niewodnicza´nski Institute of Nuclear Physics, 9 PL 31-342 Krak´ow, Poland 1 † Division de Physique Th´eorique, c Institut de Physique Nucl´eaire, F-91406, Orsay Cedex e and LPTPE Universit´e P. M. Curie, 4 Place Jussieu, F-75252, Paris Cedex 05, France D 1 Abstract. The scalar – isoscalar ππ phase shifts are analysed using a separable 1 potential model of three coupled channels (ππ , KK and an effective 2π2π system). Model parameters are fitted to two sets of solutions obtained in a recent analysis of the 2 CERN-Cracow-Munich measurements of the π−p ↑ → π+π−n reaction on a polarized v target. A relatively narrow (90 – 180 MeV) scalar resonance f (1400 − 1460) is found, 7 0 together with a wide f (500) (Γ ≈ 500 MeV) and the narrow f (980) state. 3 0 0 3 2 Recently the CERN-Cracow-Munich data [1] for the π−p↑ → π+π−n reaction 1 7 on a polarized target were analysed in Ref. [2]. Four solutions for the isoscalar 9 S-wave phase shifts from the ππ threshold up to 1600 MeV were found and two / h of them, called ”down-flat” and