相关论文: Heavy quarkonium hyperfine structure and leptonic …
The radiative spin-flip transition rates of heavy quarkonium states depend sensitively on the matrix elements of the effective confining interaction through the associated two-quark exchange current operator. The Hamiltonian model based on…
As double heavy quarkonia, charmonium and bottomonium are generally considered to have small relativistic corrections and can be treated using nonrelativistic models. However, this is not always the case. In this paper, we employ the…
We discuss various topics in the theory of heavy baryon decays. Among these are recent applications of the Relativistic Three Quark Model to semileptonic, nonleptonic, one-pion and one-photon transitions among heavy baryons, new higher…
We qualitatively corroborate the results of W. Roberts and M. Pervin in Int. J. Mod. Phys. A 24, 2401 (2009) according to which hyperfine mixing greatly affects the decay widths of $b\to c$ semileptonic decays involving doubly heavy $bc$…
Details of a recent calculation of O(alpha_s^2) corrections to the decay b -> c,l,nu_l, taking into account the c-quark mass, are described. Construction of the expansion in the mass ratio m_c/m_b as well as the evaluation of new four-loop…
Semileptonic decays of Lambda_b and Lambda_c baryons are studied within the Relativistic Three-Quark Model using finite heavy quark mass values. Employing the same parameters as have been used previously for the description of exclusive…
The rate for the final state radiation of hadrons in leptonic $Z$ decays is evaluated, using as input experimental data for $\sigma (e^+e^-\to hadrons)$ in the low energy region. Configurations with a lepton pair of large and a hadronic…
Although the spectra of heavy quarkonium systems have been successfully explained by certain QCD motivated potential models, their strong decays are still an open problem. We perform a microscopic calculation of vector charmonium strong…
The hyperfine splittings in heavy quarkonia are studied in a model-independent way using the experimental data on di-electron widths. Relativistic correlations are taken into account together with the smearing of the spin-spin interaction.…
Finite-temperature spectra of heavy quarkonia are calculated by combining potential model and thermofield dynamics formalisms. The mass spectra of the heavy quarkonia with various quark contents are calculated. It is found that binding mass…
In this review I cover recent developments concerning the construction of non-relativistic effective theories for perturbative heavy quark-antiquark systems and heavy quark mass definitions. I then discuss next-to-next-to-leading order…
In this article, we perform an systematic study of the radiative transitions among the bottomonium states based on the heavy quarkonium effective theory, and make predictions for the ratios among the radiative decay widths of a special…
Quark-gluon decays of heavy paraquarkonia $^1 S_0(\bar Q Q) \to \bar q q g$ are investigated with account of the masses of final quarks. The decay widths and the energy distributions of the final quarks and gluons are calculated in…
Novel relativistic expressions are used to calculate the weak decay constants of pseudoscalar and vector mesons within the constituent quark model. Meson wave functions satisfy the quasipotential equation with the complete relativistic…
The phenomenology of leptonic decays of quarkonia holds many interesting features: for instance, it can establish constraints on scenarios beyond the Standard Model with the Higgs sector enriched by a light CP-odd state. In the following…
The mass spectra and electromagnetic decay rates of charmonium, bottomonium and B_c mesons are comprehensively investigated in the relativistic quark model. The presence of only heavy quarks allows the expansion in powers of their…
Using a specific scheme of the QCD sum rules, one derives the relation for leptonic constants of $nS$-wave heavy qiarkonia, so $f^2_{n_1}/f^2_{n_2}= n_2/n_1$, that does not depend on the quarkonium content, and it is in a good agreement…
In the heavy quark limit a heavy baryon which contains two heavy quarks is believed to be composed of a heavy diquark and a light quark. Based on this picture, we evaluate the weak semileptonic decay rates of such baryons. The transition…
The decay rates of $c\bar{c}$ and $b\bar{b}$ through two-photon or two-gluon annihilations are obtained by using totally relativistic decay amplitudes and a sophisticated quantum-chromodynamic potential model for heavy quarkonia. Our…
We give a short and basic introduction to our covariant Dyson-Schwinger-Bethe-Salpeter-equation approach using a rainbow-ladder truncated model of QCD, in which we investigate the leptonic decay properties of heavy quarkonium states in the…