相关论文: QCD in beauty decays: successes and puzzles
The status of the QCD-based heavy quark expansion is briefly reviewed. A good agreement between properly applied theory and new precision data is observed. Critical remarks on certain recent claims from HQET are presented. Recent…
I give an introduction to the QCD-based theory of the heavy flavor hadrons and their weak decays. Trying to remain at the next-to-elementary level and skip technicalities, I concentrate on the qualitative description of the most important…
Inclusive heavy-flavour decays can be described through $1/m_Q$ expansions derived from QCD with the help of an operator product expansion. I sketch their methodology and apply them first to semileptonic B decays; $|V(cb)|$ can be extracted…
I review the status of the modern theoretical approach to weak decays of heavy flavor hadrons based on the 1/m_Q expansion in QCD. The qualitative features are explained and the subtleties in simultaneously incorporating perturbative and…
We review some selected topics in the decays of heavy flavours, beauty and charm, which are of principal interest at HERA-B and HERA. The topics in $B$ physics include: an update on the quark mixing matrix and CP violating phases, issues…
`Anyone who keeps the ability to see beauty never grows old' Franz Kafka. In the last few years considerable progress has been achieved in our understanding of the decays of heavy flavour hadrons. One can now calculate inclusive transition…
Recent developments in the theory of weak decays of heavy flavours are reviewed. Applications to exclusive semileptonic B decays, the semileptonic branching ratio and charm counting, beauty lifetimes, and hadronic B decays are discussed.
The Heavy Quark Expansion (HQE) has become an extremely powerful tool in flavor physics. For charm decays, where the expansion parameters $\alpha_s(m_c)$ and $\Lambda_{\rm QCD}/m_c$ are bigger than for bottom decays, it remains to be seen…
Phenomenological models of heavy flavour decays differ significantly in their predictions of global features of $B_c$ decays, like the $B_c$ lifetime or the relative weight of $c\ra s$ and $b\ra c$ transitions. The $1/m_Q$ expansion which…
The charm quark has unique properties that make it a very important probe of many facets of the Standard Model. New experimental information on charm decays is becoming available from dedicated experiments at charm factories, and through…
Exclusive B decays can be factorized as convolutions of hard scattering amplitudes involving the weak interaction with universal hadron distribution amplitudes, thus providing a new QCD-based phenomenology. In addition, semi-leptonic decay…
The heavy quark expansion implemented through an operator product expansion provides us with a treatment of inclusive decays of beauty and charm hadrons that is genuinely derived from QCD,though it requires one additional assumption, namely…
We show that one can re-arrange the Heavy Quark Expansion for inclusive weak decays of charmed hadrons in such a way that the resulting expansion is an expansion in $\Lambda_{\rm QCD} / m_c$ and $\alpha_s (m_c)$ with order-one coefficients.…
Inclusive and exclusive decays of heavy flavours look quite different from a theoretical viewpoint. We argue that inclusive decays can be treated quantitatively and report on the calculation of the perturbative corrections to the Final…
I give a brief outline of the theoretical framework for the modern treatment of the strong interaction effects in heavy quark decays, based on first principles of QCD. This model-independent approach is required to meet the precision of…
Exclusive decays of B and D mesons are discussed with the focus on the theoretical problem how to calculate the relevant hadronic matrix elements of weak operators in the framework of QCD sum rules. The three lectures are devoted to 1.…
The inclusive decay rate b to ccs is enhanced considerably due to perturbative QCD corrections. We recalculate the dominant part of the NLO-QCD corrections, because they cannot be reconstructed from the literature and we give the full…
The importance of charm decays in the context of flavor is motivated. A theory overview on recent developments in leptonic and semileptonic decays, hadronic two-body decays, and rare decays is presented. Standard Model (SM) predictions as…
Our community has to apply {\em non}-perturbative QCD on different levels of flavor dynamics in strange, charm \& beauty hadrons and even for top quarks. We need {\em consistent} parameterization of the CKM matrix and describe weak decays…
The dressed heavy quark mass \hat{m}_Q=m_Q+\bar{{\Lambda}} with \bar{{\Lambda}} being the binding energy is introduced to characterize the heavy hadrons containing a single heavy quark. A heavy quark expansion in terms of the inverse of the…