Couplings between pion and charmed mesons

We compute the couplings , and using QCD sum rules. These couplings are important inputs in the meson-exchange model calculations used to estimate the amount of absorption due to pions and rho mesons in heavy-ion collisions. Our sum rules are constructed at the first order in the pion momentum , which give the couplings that are not trivially related to the soft-pion theorem. Our calculated couplings, which somewhat depend upon the values of the heavy meson decay constants, are , , and . Received: 10 October 2001 / Revised version: 25 October 2001 / Published online: 7 December 2001     

Electromagnetic mass differences of the old and the charmed mesons

We predict for M_?⁺?M_?⁰ the values -3.4 ± 0.8 MeV using the ?-ω mixing and the quark model, respectively. The extracted parameters indicate the necessity of a relativistic treatment of the old mesons. The problem of extrapolating these parameters to the charmed mesons is discussed. Under conservative assumptions, we predict 1.7 ? M_D⁰ ? 2.2 MeV and .     

Asymptotic symmetry for the charmed and upsilon vector mesons

New duality is used to predict the leptonic width of the upsilon meson and derive a generalization of Yennie's relation assuming that is a Q$\text{Q}$ state of a new quark. Large symmetry breakings are found for processes D¹ → Dπ, D¹ → Dγ, F¹ → Fγ. The leptonic widths of some excited vector states are also calculated.     

Ds1(2536)+ decays and the structure of P-wave charmed strange mesons

We calculate the D s 1 (2536) + decays into D*K channels,including the decay D s 1 (2536) + → D + π-K + through a virtual D*0 in a constituent quark model.Widths and S/D amplitudes ratio are in agreement with the recent Belle and BABAR data,being the results sensitive to 1 P 1 and 3 P 1 mixture.     

Estimating the production rates of D-wave charmed mesons via the semileptonic decays of bottom mesons

Using the covariant light-front approach with conventional vertex functions, we estimate the production rates of D-wave charmed/charmed-strange mesons via the B_((s)) semileptonic decays. As the calculated production rates are significant, it seems possible to experimentally search for D-wave charmed/charmed-strange mesons via semileptonic decays, which may provide an additional approach for exploring D-wave charmed/charmed-strange mesons.     

Inclusive photoproduction cross sections of charmed mesons and baryons

The various mechanisms which may be responsible for charm photoproduction are reviewed and compared to experimental data. The photongluon fusion process provides the dominant contribution to the total cross-section at present energies. Emphasis is given to the final state structure. Assuming that hadronization takes place through string fragmentation, we calculate rapidity distributions and correlations for charmed mesons and baryons.     

Soft-gluon effects in nonleptonic decays of charmed mesons

Soft-gluon effects in nonleptonic decays of D and F mesons are studied nonperturbatively by use of a QCD multipole expansion. For reasonable values of D-meson bound-state parameters, the soft-gluon effects lead to a significant difference in the lifetimes of the D⁰ and D⁺ mesons.     

Comment of PCAC and the electromagnetic mass splittings of charmed mesons

Strong PCAC and a generalization of Dashen's relation for the K⁺?K⁰ mass difference as well as non-relativistic considerations are used in order to obtain insight into the mechanism which causes the mass splitting among the charmed pseudoscalar mesons D⁺ and D⁰. We find a value of 7–8 MeV for M_D⁺?M_D⁰.     

Decays of charmed mesons via color-octet decays of the c-quark

We unify the color-octet weak transitions first studied in cq? annihilation models with the coherence structure of c-quark decay models. We find then, with a dominant c-quark decay contribution, $\text{2.3,?}{}_{\mathrm{\tau }}\text{(}\text{D}{}^{\mathrm{+}}\text{)}\text{τ(}\text{D}{}^0\text{)?3.0}$ and τ(D⁺)≈7.5×10^?13 s, not inconsistent with the trends in the experimental results.     

Properties of L=1 B(1) and B(2)* mesons

This Letter presents the first strong evidence for the resolution of the excited B mesons B(1) and B(2)* as two separate states in fully reconstructed decays to B(+)(*)pi(-). The mass of B(1) is measured to be 5720.6+/-2.4+/-1.4 MeV/c(2) and the mass difference DeltaM between B(2)* and B(1) is 26.2+/-3.1+/-0.9 MeV/c;{2}, giving the mass of the B(2)* as 5746.8+/-2.4+/-1.7 MeV/c(2). The production rate for B(1) and B(2)* mesons is determined to be a fraction (13.9+/-1.9+/-3.2)% of the production rate of the B+ meson.