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تسجيل مستخدم جديدDetermination of the strangeness content of light-flavour isoscalars from their production rates in hadronic Z decays at LEP
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V.A. Uvarov
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A new phenomenological approach is suggested for determining the strangeness content of light-flavour isoscalars. This approach is based on phenomenological laws of hadron production related to the spin, isospin, strangeness content and mass of the particles. From the total production rates per hadronic Z decay of all light-flavour hadrons, measured so far at LEP, the values of the nonstrange-strange mixing angles are found to be |phi_P| = 42.3^{circ} pm 3.5^{circ}, |phi_V| = 10^{circ} pm 8^{circ}, |phi_T| = 16^{circ} pm 11^{circ} and |phi_S| = 13^{circ} pm 9^{circ}. Our results on the eta-eta^{prime}, omega-phi and f_2-f_2^{prime} isoscalar mixing are consistent with the present experimental evidence. The strangeness content obtained for the f_0(980) scalar/isoscalar is not consistent with the values supported by recent model studies and is discussed further in the framework of our approach and the K-matrix analysis.
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A new phenomenological approach is suggested to determine the strangeness contents of light-flavour isoscalars. This approach is based on phenomenological laws of hadron production related to the spin, isospin, strangeness content and mass of the par
ticles. The ``effective numbers of s and bar{s} quarks in the isoscalar partners i_1 and i_2 are given by the nonstrange-strange mixing angle phi: k(i_1)=2sin^2phi and k(i_2)=2cos^2phi. From the total production rates per hadronic Z decay of all light-flavour hadrons measured so far at LEP the values for k are found to be: k(eta) equiv 2-k(eta^{prime}) = 0.91 pm 0.12, k(phi) equiv 2-k(omega) = 1.94 pm 0.09, k(f_2^{prime}) equiv 2-k(f_2) = 1.84 pm 0.21 and k(f_0) = 0.09 pm 0.13. Our results on the eta--eta^{prime}, omega--phi and f_2--f_2^{prime} isoscalar mixing are consistent with the present experimental evidence. Quite remarkably, our value for k(eta) corresponds to the singlet-octet mixing angle theta_P = -12.4^{circ} pm 3.5^{circ}. The obtained strangeness content of the f_0(980) scalar/isoscalar is not consistent with the values supported by different model studies. However, taking the f_0(980) in our analysis with the mass of the bare state (K-matrix pole) f_0^{bare}(720 pm 100), the mixing angle is found to be: |phi_S^{bare}| = 73^{circ} pm 7^{circ} pm 24^{circ}, in good agreement with the prediction of the K-matrix analysis.
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