Speaker
Dmitri Melikhov
(SINP, Moscow State University and HEPHY)
Description
We discuss strong couplings $g_{VPP}$ and $g_{VVP}$ ($V$ and $P$ being
vector and pseudoscalar mesons, respectively) containing one charm and one light quark ($u$, $d$,or $s$) or two charm quarks. We demonstrate that many existing results from QCD sum rules exhibit an unrealistic picture of $SU(3)$-violating effects. We present new calculations of these couplings from the relativistic dispersion approach based on constituent quark picture and show that our results provide a very reasonable picture of the $SU(3)$-violating effects for a broad set of strong couplings. In many cases our results are substantially larger than those reported by QCD sum rules. We reveal the origin of the discrepancies between the results from the two methods and point the shortcomings of the existing QCD sum-rule calculations.
Author
Dmitri Melikhov
(SINP, Moscow State University and HEPHY)
