σ and ρ coupling constants for the charmed and beauty mesons

초록

We investigate the sigma and rho coupling constants for the DD and D* D* interactions, based on correlated 2 pi exchange in the DD and D* D* interactions. Starting from the D (D) over bar -> pi pi and D*(D) over bar* -> pi pi amplitudes derived in the pseudophysical region (4m(pi)(2) <= t <= 52m(pi)(2)) with the S- and P-wave 2 pi correlations considered, we obtain the spectral functions for the DD -> DD and D*D* -> D* D* amplitude with correlated S- and P-wave 2 pi exchanges. Using the pole approximation, we estimate the DD sigma, DD rho, D*D*sigma, and D*D*rho coupling constants. We extended phenomenologically the present results to the region in t <= 0 and compare them with those from lattice QCD. The results are also compared with those of other models. We also present the results of the BB sigma, BB rho, B* B* sigma, and B*B*rho coupling constants. We observe that it is unlikely that the sigma and rho coupling constants for the B and B* mesons are the same as those for the D and D* mesons. On the contrary, they are quite larger than those for the charmed mesons.

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