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Interactions of - mesons with heavy quarks. Avakyan E. Z. , Avakyan S. L. GSTU, Gomel. MIXING SCHEMES (only u,d,s -quarks). 1. Mixing: Where The flavor structure of and :. MIXING SCHEMES only u,d,s -quarks.
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Interactions of - mesons with heavy quarks Avakyan E. Z., Avakyan S. L. GSTU, Gomel
MIXING SCHEMES (only u,d,s-quarks) 1. Mixing: Where The flavor structure of and :
MIXING SCHEMES only u,d,s-quarks 2. MIXING IN THE OCTET – SINGLET BASIS The pseudoscalar nonet can be displayed as: So
HEAVY QUARK ADMIXTURES TO LIGHT PSEUDOSCALAR MESONS Problem: ClEO mesuarment of branching fraction unexpetedly large.[CLEO coll ab. B.H.Behrens et.al. Phis.Rev.Lett.80,3710(1998)] Mixing :
WAYS TO DEFINE MIXING PARAMETERS • The radiative decays of η – mesons [T.Feldman, P.Kroll and B. Stech, Phys.Rew. D58,114006 (1998) • Radiative Ј/Ψ – decays • [K.Chao, Nucl.Phys B317,597(1989) • Rations of weak decays constants
QUARK MODEL • The hadronic interactions will be described in the Relativistic Constituent Quark Model (RCQM). [M.A.Ivanov,M.P.Locher and V.E.Lyubovitskij, Few-BodySyst. 21,131(1996), M.A.Ivanov, V.E.Lyubovitskij,Phys.Lett., B408,435(1997)] The coupling of the meson M into its constituents and is given by Lagrangian where are Dirac and Gell-Mann matrices.
QUARK MODEL The function characterizes the finite size of meson and is given by: The coupling constant is determined by compositeness condition: where - the derivative of the mass function of meson.
QUARK MODEL Example of evaluation of one – loop diagram: After calculating Tr and performing α-parameterization one finds: where Next we use Cauchy integral representation for
QUARK MODEL We use α-parameterization once more and find The contour integral can be done again by Cauchy’s theorem. On substitution of and shift , after rotation ,one receives:
MESON-QUARK INTERACTION CONSTANTS Pseudoscalar meson constant THE MIXING:
DECAY Decay amplitude: Decay width: Experimental values (PDG)
DECAY THE MIXING:
To define the experimental values were used. For mixing: For mixing: So we find the quark content of physical mesons
RADIATIVE TRANSITIONS BETWEEN LIGHT PSEUDOSCALAR AND VECTOR MESONS Decay amplitude: Decays width:
RADIATIVE TRANSITIONS BETWEEN LIGHT PSEUDOSCALAR AND VECTOR MESONS • NUMERICAL RESULTS FOR RADIATIVE DECAYS
RADIATIVE TRANSITIONS BETWEEN LIGHT PSEUDOSCALAR AND VECTOR MESONS • NUMERICAL RESULTS FOR RADIATIVE DECAYS