Related papers: Relativity and the Minimum Slope of the Isgur-Wise…
We present a QCD sum rule calculation of the spin-symmetry violating universal function $\chi_2(v\cdot v')$, which appears at order $1/m_Q$ in the heavy quark expansion of meson form factors. This function vanishes in the standard…
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…
In this paper, we introduce a non-minimally coupled varying speed of light and varying gravitational constant cosmological toy model. Using the Eisenhart-Duval lifting method, we extend the original minisuperspace of the model and depict…
The Integrated Sachs-Wolfe (ISW) effect is a direct signature of the presence of dark energy in the universe, in the absence of spatial curvature. A powerful method for observing the ISW effect is through cross-correlation of the Cosmic…
We present an investigation on the ligh flavor 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. It is found that the Isgur-Wise function for $B_s$ decay falls…
We review our method and numerical results for calculation of the Isgur-Wise function on the lattice. We present a discussion of the systematic errors. Using recent experimental results, we find $V_{cb} = 0.044\pm 0.005\pm .007$.…
The heavy mass limit of quark models based on the Bakamjian-Thomas cons\-truction reveals remarkable features. In addition to previously demonstrated properties of covariance and Isgur-Wise scaling, exact duality, leading to the…
We perform the isospin decomposition of proton and neutron SLAC data for moderately low $x$ in the region $0.01 \leq x \leq 0.1$. The isovector part is well described by a power behaviour $x^{\alpha}$, where $\alpha$ does not correspond to…
In a gravitational theory with a massless photon the maximum charge-to-mass ratio of black holes approaches the prediction of the Einstein-Maxwell theory as black hole mass increases: $Q_{\rm ext}/M =1+ \alpha/M^2$ for some constant…
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…
We derive the form factors relevant for decays of pseudo-scalar mesons corresponding to the semi-leptonic decay B->D l nu. The simulations are performed in the quenched approximation at beta=6.0 and beta=6.2 using a non-perturbatively…
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…
A sum rule relating the widths of the decays of mesons belonging to heavy quark multiplets, having the same parity and light quark spin j, into the low lying $0^-$ and $1^-$ multiplet is obtained. As this sum rule follows from properties of…
We investigate specific models for a dark energy universe leading to Quasi-Rip and Pseudo-Rip cosmologies. In the Quasi-Rip model the equation of state parameter w is less than -1 in the first stage, but becomes larger than -1 in the second…
I present a very simple model, based on the model of Isgur, Scora, Grinstein and Wise \cite{ISGW}, which can be used to calculate the effects which appear at subleading order in heavy quark effective theory. I include both general formalism…
We investigate a specific model for dark energy, which lead to the Quasi-Rip cosmology. In the Quasi-Rip model, the equation of the state parameter $w$ is less than -1 in the first stage, but then in the second stage is larger than -1. The…
An effective field theoretic description of the Isgur-Wise function in heavy-meson transitions is presented which emulates soft interactions by a fermion worldline with an infinitesimal self-intersecting loop. A point-splitting…
We use the spinor helicity formalism in order to derive the dyadic forms for massless fields of various spins. We also give an iterated form of this approach in case higher spin theories are under study. This reduces calculations at hard…
In scalar-tensor theories of gravity, the equation of state of dark energy, w, can become smaller than -1 without violating any energy condition. The value of w today is tied to the level of deviations from general relativity which, in…
After a brief introduction to the Heavy-Quark Effective Theory (HQET), I review the extraction of the Isgur-Wise function from lattice QCD calculations of the matrix elements for semi-leptonic decays of heavy-light pseudoscalar mesons both…