相关论文: Topics in the Heavy Quark Expansion
I report on recent developments in the heavy-quark effective theory and its application to $B$ meson decays. The parameters of the effective theory, the spin-flavor symmetry limit, and the leading symmetry-breaking corrections to it are…
Recent achievements in the heavy quark theory are critically reviewed. The emphasis is put on those aspects which either did not attract enough attention or cause heated debates in the current literature. Among other topics we discuss (i)…
We review the current status of heavy quark symmetry and its applications to weak decays of hadrons containing a single heavy quark. After an introduction to the underlying physical ideas, we discuss in detail the formalism of the heavy…
Recent developments in the theory of heavy quarks are reviewed. In the area of heavy quark fragmentation, there has been progress in the study of both pertubative and nonperturbative processes, including the identification of new observable…
Considering nonforward scattering amplitude off the heavy quark in the Small Velocity limit two exact superconvergent sum rules are derived. The first sum rule leads to the lower bound \rho^2 > 3/4 for the slope of the Isgur-Wise function.…
Two topics in heavy quark expansion are discussed. The heavy quark potential in perturbation theory is reviewed in connection to the problem of the heavy quark mass. The nontrivial reason behind the failure of the "potential subtracted"…
We consider the dominant $c\bar{c}$ contribution to $\Delta \Gamma$ for the $B_s^0$-$\bar{B}_s^0$ system in the heavy quark limit for both $b$ and $c$ quarks. In analogy with the Bjorken-Isgur-Wise sum rule in semileptonic heavy hadron…
We investigate the nonperturbative parameters entering the heavy quark expansion for the inclusive decay rates of the $\Lambda_b$ baryon, focusing on the kinetic term $\hat{\mu}_\pi^2$ and the Darwin term $\hat{\rho}_D^3$. Recent…
These lectures contain an elementary introduction to heavy quark symmetry and the heavy quark expansion. Applications such as the expansion of heavy meson decay constants and the treatment of inclusive and exclusive semileptonic $B$ decays…
The Lambda_b to Lambda_c semileptonic decay is analyzed in the framework of heavy quark effective theory to the order of 1/m_c and 1/m_b. The QCD sum rule and large N_c predictions to the decay form factors are applied. It argues that the…
Two new sum rules were recently discovered by Le Yaouanc et al. by applying the operator product expansion to the nonforward matrix element of a time-ordered product of $b \to c$ currents in the heavy-quark limit of QCD. They lead to the…
We give improved estimates for the non-perturbative parameters appearing in the heavy quark expansion for inclusive decays. While the parameters appearing in low orders of this expansion can be extracted from data, the number of parameters…
In the leading order of the heavy quark expansion, we propose a method within the OPE and the trace formalism, that allows to obtain, in a systematic way, Bjorken-like sum rules for the derivatives of the elastic Isgur-Wise function…
We show how sum rules for the weak decays of heavy flavor hadrons can be derived as the moments of spectral distributions in the small velocity (SV) limit. This systematic approach allows us to determine corrections to these sum rules, to…
We present a number of exact relations for the heavy quark limit and develop an analytical 1/m_Q expansion for heavy mesons in the 't Hooft model. Among the new results are relation 3\mu_\pi^2=\bar\Lambda^2 - m_{sp}^2+\beta^2, 1/m_Q…
This is a short review of the present status of the dynamics of the heavy quarks extracted from QCD spectral sum rules. We discuss the determination of the ``perturbative" quark mass, the decay constants of the $D$ and $B$ mesons, the form…
The formalism and applications of chiral perturbation theory for hadrons containing a single heavy quark are discussed. We emphasize the utility of working directly with the velocity dependent ``super'' fields which appear in the chiral…
The non-factorizable terms in the operator product expansion have been recognized as one of theoretical obstacles for precision determination of the mixing parameter $V_{ub}$ from semileptonic B decays. It is pointed out here that the…
Some of the recent progress in heavy quark physics is reviewed. Special attention is paid to inclusive methods for determining Vub and factorization in nonleptonic B decays. Theoretical predictions for top-antitop production near threshold…
The quark (gluon)-hadron duality constitutes a basis for the theoretical treatment of a wide range of inclusive processes -- from hadronic \tau decays and R_{e^+e^-}, to semileptonic and nonleptonic decay rates of heavy flavor hadrons. A…