Related papers: Simultaneous decoupling of bottom and charm quarks
derivation of the effective lagrangian for non-relativistic quantum chromodynamics and the heavy quarks effective field theory is given. Our calculation provides of a simple and systematic method of calculation of the full off shell…
We investigate the influence of dynamical charm quarks on observables that depend explicitly on the charm quark fields, like the pseudo-scalar and vector masses $m_{\eta_c}$ and $m_{J/\psi}$, the hyperfine splitting…
We present a comparison of the strong couplings of light ($u$,~$d$,~and~$s$), $c$, and $b$ quarks determined from multijet rates in flavor-tagged samples of hadronic $Z^0$ decays recorded with the SLC Large Detector at the SLAC Linear…
The impact of rare lepton decays ($\mu \to e \gamma$, $\tau \to \mu \gamma$, >...) and rare $B$ and $K$ decays ($B\to \ell^+\ell^-$, $B\to \ell\nu$, $K\to \pi \nu\nu$, $K\to\ell\nu$, ...) in probing the existence of an underlying flavour…
The integrated branching fraction of the process $B\to X_s l^+l^-$ is dominated by resonance background from narrow charmonium states, such as $B\to X_s\psi\to X_s l^+l^-$, which exceeds the non-resonant charm-loop contribution by two…
The effect of non-zero c quark mass on b quark HQET Lagrangian, up to 1/m_b level, is calculated at two loops. The results are expressed in terms of dilogarithmic functions of m_c/m_b. This calculation involves on-shell two-loop…
After sketching heavy quark expansions as applied to heavy flavour decays I emphasize the relevance of nonperturbative dynamics at the charm scale for exclusive $b\to c$ modes. I address the issue of quark-hadron duality for charm and…
The perturbative three-loop result for the thermodynamic potential of QCD at finite temperature and chemical potential as obtained in the framework of dimensional reduction is compared with the exact result in the limit of large flavor…
We use recent experimental data on charmed mesons to constrain three coupling constants in the effective lagrangian describing the interactions of excited heavy-light mesons with light pseudoscalar mesons at order $m_Q^{-1}$. Predictions in…
We study the system of light mesons, charmonium and glueballs in the flavor singlet scalar channel where they can mix. We use lattice QCD simulations with an almost physical charm quark and three degenerate light quarks for two values of…
We have investigated the spectra of light-heavy quarkonia with the use of a quantum-chromodynamic potential model which is similar to that used earlier for the heavy quarkonia. An essential feature of our treatment is the inclusion of the…
We present the details and first results of a new strategy for the determination of $\alpha_s(m_Z)$. By simultaneously decoupling 3 fictitious heavy quarks we establish a relation between the $\Lambda$-parameters of three-flavor QCD and…
For a long time, investigation into the weak interactions of quarks has guided us toward understanding the Standard Model we know today. Now in the era of high precision, these studies are still one of the most promising avenues for peering…
Chiral effective field theory is utilized for extrapolating results on the $\Lambda_c N$ interaction, obtained in lattice QCD at unphysical (large) quark masses, to the physical point. The pion-mass dependence of the components that…
We compute and compare the continuum limits of several quantities in QCD with and without a dynamical charm quark. We consider both low energy quantities, like the hadronic scales $r_0$ and $t_0$, and high energy quantities, like the…
The role of charm in testing the Standard Model description of quark mixing and CP violation through measurements of lifetimes, decay constants and semileptonic form factors is reviewed. Together with Lattice QCD, charm has the potential…
Considered as a function of the quark mases, two-flavor QCD depends on three parameters, including one that is CP violating. As the masses vary to unphysical values, regions of both first- and second-order phase transitions are expected.…
Chiral perturbation theory in the two--flavour sector allows one to analyse Green functions in QCD in the limit where the strange quark mass is considered to be large in comparison to the external momenta and to the light quark masses m_u…
New results at four-loop order in perturbative QCD for the first two Taylor coefficients of the heavy quark vacuum polarization function are presented. They can be used to perform a precise determination of the charm- and bottom-quark mass.…
Possible non-standard tqZ couplings, where q=c or u, originated from general flavor-changing-neutral-current interactions are studied model-independently using the effective Lagrangian consisting of several SU(3)xSU(2)xU(1) invariant…