Related papers: Long-Distance Contributions to the $\Lambda_b\righ…
We calculate the process-independent fragmentation functions for a $\bar b$ antiquark to fragment into longitudinally and transversely polarized $B_c^*$ ($^3S_1$) mesons to leading order in the QCD strong coupling constant. In the special…
Model-independent bounds are presented for the form-factors describing the semileptonic decay $\Lambda_b\to\Lambda_ce\bar\nu_e$ at the end-point of the lepton energy spectrum. For the axial-vector form-factor $f_1^A(1)$ we obtain…
We calculate the decay width of the $\Lambda_{c}^{+}\to\Sigma^{+}\gamma$ using light-cone sum rules. For the initial quark radiation an effective Hamiltonian is constructed, where the internal quark line shrinks to a point. The final quark…
In the heavy quark limit, the heavy baryon $\Lambda_Q$ (Q=b or c) can be regarded as composed of a heavy quark and a scalar light diquark which has good spin and flavor quantum numbers. Based on this picture we establish the Bethe-Salpeter…
We calculate the vector form factor in K \to \pi l \nu semileptonic decays at zero momentum transfer f_+(0) from numerical simulations of two-flavor QCD on the lattice. Our simulations are carried out on 16^3 \times 32 at a lattice spacing…
The combined use of chiral $SU(3)$ and heavy quark symmetries allows one to relate the hadronic form factors for the decay $\bar B\to \bar K\e^+\e^-$ to those for $\bar B\to\pi\e^-\bar\nu$. We investigate departures from the symmetry limit…
We present a model-independent global analysis of hadronic form factors for the semileptonic decays $b\rightarrow c\ell\nu$ that exploits lattice-QCD data, dispersion relations, and heavy-quark symmetries. The analysis yields predictions…
The form factors of the semileptonic $B\to \pi\pi\ell\bar\nu$ decay are calculated from QCD light-cone sum rules with the distribution amplitudes of dipion states. This method is valid in the kinematical region, where the hadronic dipion…
In this article, the electroweak transition form factors of $\Lambda_b\to\Lambda_c$ and $\Xi_b\to\Xi_c$ are analyzed within the framework of three-point QCD sum rules. In phenomenological side, all possible couplings of interpolating…
The successful operation of LHC provides a great opportunity to study the processes where heavy baryons are involved. {In this work we mainly study} the weak transitions of $\Sigma_b\to \Sigma_c$. Assuming the reasonable quark-diquark…
We demonstrate that the B->D(*) l nu form factors can be accurately predicted given the slope parameter rho^2 of the Isgur-Wise function. Only weak assumptions, consistent with lattice results, on the wavefunction for the light degrees of…
The form factors for the $B-->\pi$ transition are evaluated in the entire momentum transfer range by using the constraints obtained in the framework combining the heavy quark expansion and chiral symmetry for light quarks and the quark…
In the large $N_c$ limit, all hyperon decays involving the same quark diagram $Q\to Q'$ are described by a single weak form factor $\eta_{QQ'}(w)$. No assumption on the mass of $Q$ or $Q'$ is necessary, making our results applicable to both…
We present an improved calculation of all B -> light pseudoscalar formfactors from light-cone sum rules, including one-loop radiative corrections to twist-2 and twist-3 contributions, and leading order twist-4 corrections. The total…
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…
The Isgur-Wise function vastly reduces the weak-decay form factors of hadrons containing one heavy quark. In this paper, we extract the Isgur-Wise functions from the instantaneous Bethe-Salpeter method, and give the numerical results for…
We present results for the strong widths corresponding to the $\Sigma_c\to \Lambda_c \pi$, $\Sigma_c^{*}\to \Lambda_c \pi$ and $\Xi_c^{*}\to \Xi_c \pi$ decays. The calculations have been done in a nonrelativistic constituent quark model…
This PhD thesis is a first step towards the control of the quantum corrections in the Resonance Chiral Theory, the suggested framework to handle QCD in the resonance region. After a theoretical introduction, Chapter 3 is devoted to…
We present results for different observables in weak decays of pseudoscalar and vector mesons with a heavy $c$ or $b$ quark. The calculations are done in a nonrelativistic constituent quark model improved at some instances by heavy quark…
A systematic calculation for the transition form factors of heavy to light mesons ($B,B_s,D,D_s \to \pi, K, \eta, \rho, K^*, \omega, \phi$) is carried out by using light-cone sum rules in the framework of heavy quark effective field theory.…