Related papers: The Isgur-Wise Function in Small Velocity Limit

Sum rules based upon heavy quark effective theory indicate that the Isgur-Wise function $\xi(w)$ has a minimum slope as w approaches 1, which is zero for light degrees of freedom with zero spin and 1/4 for light spin 1/2. Quark-model…

We derive optimal upper and lower bounds on the slope of the Isgur-Wise function at the zero recoil point in terms of the sum of the $\Upsilon B\bar{B}$ couplings, estimated recently from a $QCD$ Spectral Sum Rule ($QSSR$). The problem is…

Using the OPE, we obtain new sum rules in the heavy quark limit of QCD, in addition to those previously formulated. Key elements in their derivation are the consideration of the non-forward amplitude, plus the systematic use of boundary…

Using the OPE and the trace formalism, we have obtained a number of sum rules in the heavy quark limit of QCD that include the sum over all excited states for any value $j^P$ of the light cloud. We show that these sum rules imply that the…

From sum rules in the heavy quark limit of QCD, using the non-forward amplitude, we demonstrate that if the slope rho^2 = -xsi'(1) of the Isgur-Wise function xsi(w) attains its lower bound 3/4 (as happens in the BPS limit proposed by…

We study light quark dependence of the Isgur-Wise function for $B_a\rightarrow D_a$ and $B_a\rightarrow D^{*}_a$ in the framework of QCD sum rules. At zero recoil , all the Isgur-Wise functions equal as required by heavy quark symmetry and…

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…

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…

Using the OPE, we formulate new sum rules in the heavy quark limit of QCD. These sum rules imply that the elastic Isgur-Wise function $\xi (w)$ is an alternate series in powers of $(w-1)$. Moreover, one gets that the $n$-th derivative of…

We use the Dirac equation with a ``(asymptotically free) Coulomb + (Lorentz scalar) linear '' potential to estimate the light quark wavefunction for $ q\bar Q$ mesons in the limit $m_Q\to \infty$. We use these wavefunctions to calculate the…

The QCD inspired potential model persued by us earlier has been recently modified to incorporate an additional factor 'c' in the linear cum Coulomb potential. While it felicitates the inclusion of standard confinement parameter b = 0.183GeV…

We estimate the sum of the $\Upsilon \bar BB $ couplings using QCD Spectral Sum Rules (QSSR). Our result implies the phenomenological bound $\xi'(vv'=1) \geq -1.04$ for the slope of the Isgur-Wise function. An analytic estimate of the…

We have recently reported the calculation of slope and curvature of Isgur-Wise function based on Variationally Improved Perturbation Theory (VIPT) in a QCD inspired potential model. In that work, Coulombic potential was taken as the parent…

Using previously formulated sum rules in the heavy quark limit of QCD, we demonstrate that if the slope rho^2 = -xi'(1) of the Isgur-Wise function xi(w) attains its lower bound 3/4, then all the derivatives (-1)^L xi^(L)(1) attain their…

We consider the Isgur-Wise function xi(omega) within a new modified version of a heavy-light chiral quark model. While early versions of such models gave too small absolute value of the slope, namely xi'(1) of about -0.4 to -0.3, we show…

We propose a group theoretical method to study Isgur-Wise functions. A current matrix element splits into a heavy quark matrix element and an overlap of the initial and final clouds, related to the IW functions, that contain the long…

The integral representation for Isgur -- Wise function (IWF) is obtained in the framework of instant--form relativistic Hamiltonian dynamics for mesons with one heavy quark. The upper and lower limits are calculated for the slope parameter…

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.…

We complete the QCD sum rule analysis of the Isgur Wise form factor $\xi(v\cdot v')$ at next-to-leading order in renormalization-group improved perturbation theory. To this end, the exact result for the two-loop corrections to the…

We calculate the Isgur-Wise function on the lattice, simulating the light quark with the Wilson action and the heavy quark with a direct lattice implementation of the heavy-quark effective theory. Improved smearing functions produced by a…