Related papers: Long-Distance Contributions to the $\Lambda_b\righ…
First order power corrections to current matrix elements between heavy meson or $\Lambda_\Q$ baryon states are shown to vanish at the zero recoil point to all orders in QCD. Five relations among the six form factors that parametrize the…
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…
Exclusive semileptonic decays B->D_1(2420)l\bar\nu and B->D_2^*(2460)l\bar\nu are studied at the subleading order of the heavy quark expansion. The subleading Isgur-Wise functions resulted from the kinetic energy and chromomagnetic…
The slope and curvature of Isgur Wise function for $B_{c}$ meson is computed in a QCD potential model in two different approaches of choosing the perturbative term of the Cornell potential. Based on heavy quark effective theory the…
We consider the form factors for the radiative semileptonic decays $\bar{B}(v) \rightarrow D^{(*)}(v') \ell {\bar \nu}_\ell \gamma$ in the kinematic region where the photon momentum, $k$, is small enough that heavy quark symmetry (HQS) can…
The $\Lambda_b \to p$ semileptonic decay is analyzed by using QCD sum rules within the framework of heavy quark effective theory. The Isgur-Wise function of $\Lambda_b \to p l \bar\nu$ has been calculated. The decay width is given.
Upper and lower bounds are established on the Lambda_b -> Lambda_c semileptonic decay form factors by utilizing inclusive heavy-quark-effective-theory sum rules. These bounds are calculated to leading order in Lambda_QCD/m_Q and alpha_s.…
The weak decays of a spin-$1/2$ doubly charm baryon (${\cal B}_{cc}$) to a spin-$1/2$ singly charm baryon (${\cal B}_c$) and a light vector meson ($V$) are studied under a phenomenological scheme. The contributions are classified into…
We derive expressions for strangeness-changing scalar form factors, which incorporate known theoretical constraints both at low and high energies. Their leading behaviour in the limit of a large number of colours is calculated from the…
In this paper a model-independent relation which holds for the long distance part of the Fourier transform of the electromagnetic form factors of the nucleon in the large $N_c$ and chiral limits is demonstrated. This relation was previously…
Semileptonic decay of the $B_c$ meson is studied in the heavy quark limit. The six possible form factors for $B_c \rightarrow B_s (B^0),B_s^* (B^{*0})$ semileptonic decay are determined by two invariant functions. Only one of these…
We study the weak decays of the charmed baryon $\Omega_c^0$ to the $\Omega^-$ baryon within the framework of QCD sum rules. A three-point correlation function is defined for calculating eight form factors governing the $\Omega_c^0 \to…
To know and understand form factors of hadronic currents is of decisive importance for analysing exclusive weak decays. The ratios of different form factors of a given process depend on the relativistic spin structure of initial and final…
Nonperturbative effects in exclusive reactions $B\to K^{(*)}ll$ are discussed. Form factors which describe the main long-distance contribution to the meson transition amplitude are calculated within the dispersion formulation of the quark…
A simple model of Omega_Q and Omega_Q^(*) baryons containing one heavy quark Q is constructed. Amplitudes are represented by loop graphs with one line for the heavy quark and another for the light degrees of freedom. The latter are modelled…
We present our study on $B \to \pi l \nu$ semileptonic decay form factors with NRQCD action for heavy quark from a quenched lattice QCD simulation at $\beta$=5.9 on a $16^3\times 48$ lattice. We obtain form factors defined in the context of…
Assuming simple properties of the spectator particle in weak decays the form factors of hadronic current matrix elements are shown to be related to a single universal function. The Isgur-Wise result for heavy-to-heavy transitions follows as…
A systematic approach to long-distance effects in exclusive radiative weak $B$ decays is presented, based on a combination of the heavy quark limit with perturbative QCD. The dominant long-distance effects, connected with weak annihilation…
Thanks to the remarkable achievements of LHC, a large database on baryons has been accumulated, so it is believed that the time for precisely studying baryons especially heavy baryons, has come. By analyzing the data, the quark-diquark…
The transition form factors describing the semileptonic decays of heavy pseudoscalar mesons are investigated within a relativistic constituent quark model formulated on the light-front. For the first time, the form factors are calculated in…