%0 Journal Article
%T The sigma and f_0(980) from Ke4 + pi-pi scatterings data
%+ Laboratoire de Physique Théorique et Astroparticules (LPTA)
%A Mennessier, Gerard
%A Narison, Stephan
%A Wang, X. -G.
%< avec comité de lecture
%Z LPTA:10-007
%@ 0370-2693
%J Physics Letters B
%I Elsevier
%V 688
%N 1
%P 59-66
%8 2010-04-25
%D 2010
%Z 1002.1402
%R 10.1016/j.physletb.2010.03.031
%K Meson properties
%K Meson–meson interactions
%K S-matrix
%K Non-perturbative calculations
%Z Physics [physics]/High Energy Physics - Phenomenology [hep-ph]
%Z Physics [physics]/High Energy Physics - Experiment [hep-ex]
%Z Physics [physics]/High Energy Physics - Lattice [hep-lat]
%Z Physics [physics]/Nuclear Theory [nucl-th]Journal articles
%X We systematically reconsider, within an improved "analytic K-matrix model", the extraction of the sigma = f_0(600) and f_0(980) masses, widths and hadronic couplings using new Ke4 = K-->pi-pi e nu_e data on pi-pi phase shift below 390 MeV and different sets of pi-pi--> pi-pi / K-K scatterings data from 400 MeV to 1.4 GeV. Our results are summarized in Tables 1, 2 and 5. In units of MeV, the complex poles are: M_sigma=452(12) - i 260(15) and M_f=981(34) -i 18(11), which are comparable with some recent high-precision determinations and with PDG values. Besides some other results, we find: |g_{sigma K+K-}|/|g_{sigma pi+pi-}|=0.37(6) which confirms a sizeable g_{sigma K+K-} coupling found earlier, and which disfavours a large pi-pi molecule or four-quark component of the sigma, while its broad pi-pi width (relative to the one of the rho-meson) cannot be explained within a \bar qq scenario. The narrow pi-pi width of the f_0(980) and the large value: |g_{f K+K-}|/|g_{f pi+pi-}|=2.59(1.34), excludes its pure (\bar uu+\bar dd) content. A significant gluonium component eventually mixed with \bar qq appears to be necessary for evading the previous difficulties.
%G English
%L hal-00457346
%U https://hal.science/hal-00457346
%~ IN2P3
%~ LPTA
%~ CNRS
%~ UNIV-MONTP2
%~ UNIV-MONTPELLIER
%~ UM1-UM2