Related papers: Renormalisation scale setting for D-mixing
An effective theory to treat the dense nuclear medium by the perturbative expansion method is proposed as a natural extension of the Heavy Baryon Chiral Perturbation Theory (HBChPT). Treating the Fermi momentum scale as a separate scale of…
The partial widths of the decays $D^+_s \to \phi \pi^+$ and $D^+_s \to \pi^+ \pi^+ \pi^-$ - nonresonant are computed within the effective quark model with chiral symmetry involving Heavy quark effective theory (HQET) and Chiral perturbation…
We study the renormalization group evolution (RGE) of new physics contributions to (semi)leptonic charged-current meson decays, focusing on operators involving a chirality flip at the quark level. We calculate their evolution under…
The Standard Model decay rate of the $B_c$ meson is discussed together with a novel approach that uses experimental data in combination with an operator product expansion. In the new method differences of $B,\,D$ and $B_c$ meson decay rates…
Commensurate scale relations relate observables to observables and thus are independent of theoretical conventions, such as the choice of intermediate renormalization scheme. The physical quantities are related at commensurate scales which…
The decay constants of the charmed heavy pseudoscalar D and D_s mesons are revisited within a recently developed novel approach to dispersive QCD sum rules which relies on an unprejudiced implementation of quark-hadron duality. The proposed…
The main obstacle in describing inclusive decay spectra in QCD - which, in particular, limits the precision in extrapolating the measured \bar{B} \to X(s) gamma rate to the full phase space as well as in extracting |V_{ub}| from inclusive…
A phenomenological analysis of lifetimes of bottom and charmed hadrons within the framework of the heavy quark expansion is performed. The baryon matrix element is evaluated using the bag model and the nonrelativistic quark model. We find…
The two-Higgs doublet model (2HDM) provides an excellent benchmark to study physics beyond the Standard Model (SM). In this work we discuss how the behaviour of the model at high energy scales causes it to have a scalar with properties very…
We present a sum-rule extraction of the decay constants of the D, Ds, B, and Bs mesons from the two-point correlator of heavy-light pseudoscalar currents [1]. Our main emphasis is laid on the control over the uncertainties in the decay…
We improve a previous quenched result for heavy-light pseudoscalar meson decay constants with the light quark taken to be the strange quark. A finer lattice resolution (a ~ 0.05 fm) in the continuum limit extrapolation of the data computed…
We present a computation of B-meson decay constants from lattice QCD simulations within the framework of Heavy Quark Effective Theory for the b-quark. The next-to-leading order corrections in the HQET expansion are included…
The phenomenology of the pseudo scalar mesons D_s and B_s and of the vector mesons D_s* and B_s* was investigated in simulations of quenched lattice QCD. The work is particularly focused on the continuum limit and the minimisation of all…
We study lifetimes of heavy mesons in the 't Hooft model, a large-$N_c$ theory of strong interaction in two-dimensional spacetime. Since this model is solvable, one can evaluate the total decay widths through hadronic amplitudes that are…
Sum rules for exclusive production of heavy meson pairs in $e^+e^-$ annihilation are used to evaluate the $\Upsilon(4S) \to B \bar B$ and $\psi(3770) \to D \bar D$ decay widths. Infinitely heavy quark limit is discussed, so that scaling law…
A possibility is considered of explaining the low experimental value of the ratio of the lifetimes tau(Lambda_b)/tau(B_d) by a new `centiweak' four-quark interaction, i.e with a strength on the order of 10^{-2}G_F. It is noted that the…
The setting of the renormalization scale ($\mu_r$) in the perturbative QCD (pQCD) is one of the crucial problems for achieving precise fixed-order pQCD predictions. The conventional prescription is to take its value as the typical momentum…
We discuss direct $CP$ violation in the standard model by giving a new estimate of $\varepsilon'/\varepsilon$ in kaon decays. Our analysis is based on the evaluation of the hadronic matrix elements of the \mbox{$\Delta S =1$} effective…
Theoretical predictions for inclusive semileptonic B decay rates are rewritten in terms of the Upsilon(1S) meson mass instead of the b quark mass, using a modified perturbation expansion. This method gives theoretically consistent and…
After the recent high precision determinations of $V_{us}$ and $V_{ud}$, the first row of the CKM matrix shows more than $4\sigma$ deviation from unitarity. Two possible scenarios beyond the Standard Model can be investigated in order to…