Related papers: Modelling form factors in HQET
A review of the hadron electromagnetic form factors obtained in a light-front constituent quark model, based on the eigenfunctions of a mass operator, is presented. The relevance of different components in the q-q interaction for the…
We present recent progress in constructing heavy quarkonia light-front wave functions from the light-front quark model, a relativistic framework well-suited for describing partonic structure and hadronic form factors. In this proceeding, we…
Hadronic form factors for semileptonic decay of the $\Lambda_c$ are calculated in a nonrelativistic quark model. The full quark model wave functions are employed to numerically calculate the form factors to all relevant orders in ($1/m_c$,…
Rare $\Lambda_b\to\Lambda l^+l^-$ and $\Lambda_b\to\Lambda\gamma$ decays are investigated in the relativistic quark model based on the quark-diquark picture of baryons. The decay form factors are calculated with the account of all…
The application of relativistic constituent quark models to the evaluation of the electromagnetic properties of the nucleon and its resonances is addressed. The role of the pair creation process in the Feynmann triangle diagram is discussed…
We study transition form factors for radiative and rare semi-leptonic B-meson decays into light pseudoscalar or vector mesons, combining theoretical constraints and phenomenological information from Lattice QCD, light-cone sum rules, and…
Hadronic form factors for the rare weak transitions $\Lambda_{b}\rightarrow\Lambda^{(*)}$ are calculated using a nonrelativistic quark model. The form factors are extracted in two ways. An analytic extraction using single component wave…
We investigate the form factors for exclusive semileptonic decays of $B$-meson to $D,~D^*$, based on the parton picture and helped by the results of the HQET. We obtain the numerical results for the slope of the Isgur-Wise function, which…
The wave function of a composite system is defined in relativity on a space-time surface. In the explicitly covariant light-front dynamics, reviewed in the present article, the wave functions are defined on the plane $\omega \cd x=0$, where…
In this article, we study the rare decays corresponding to $b \to d$ transition in the framework of the covariant confined quark model. The transition form factors for the channels $B^{+(0)} \to (\pi^{+(0)}, \rho^{+(0)},\omega)$ and $B_s^0…
The form factors of weak decays of the B meson to orbitally excited scalar, axial vector and tensor light mesons are calculated in the framework of the QCD-motivated relativistic quark model based on the quasipotential approach.…
Heavy-to-heavy semileptonic decays, particularly the bottom-to-charm quark transitions, are essential for testing the Standard Model (SM) and extracting the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements. These decays have been extensively…
A calculation of hadronic timelike form factors in the Poincar\'e-covariant Bethe-Salpeter formalism necessitates knowing the analytic structure of the non-perturbative quark-photon vertex in the context of the Poincar\'e-covariant…
In this article, we study the radiative transitions among the vector and scalar heavy quarkonium states with the covariant light-front quark model. In calculations, we observe that the radiative decay widths are sensitive to the constituent…
The electromagnetic form factors of light and heavy pseudoscalar mesons are calculated within two covariant constituent-quark models, a light-front and a dispersion relation approach. We investigate the details and physical origins of the…
We revisit the calculation of the width for the radiative decay of a $1^{+-}$ heavy $Q \bar Q$ meson via the channel $1^{+-} \to 0^{-+} +\gamma$ in the covariant light-front quark model. We carry out the reduction of the light-front…
We present covariant predictions of relativistic constituent quark models for pi and eta decay widths of N and Delta resonances. The results are calculated for a model decay operator within the point-form spectator approximation. It is…
We describe the form factors for B to rho lepton neutrino and B to K* gamma decays with just two parameters and the two form factors for B to pi lepton neutrino with a further two or three parameters. The parametrizations are consistent…
We discuss preliminaries of a calculation of the form factors for the semileptonic decays B -> pi lv, B_s -> K lv, and B -> K ll. We simulate with NRQCD heavy and HISQ light valence quarks on the MILC 2+1 dynamical asqtad configurations.…
We derive a new parton-like formula, which establishes a simple connection between the electroweak decay rate $\Gamma (\bar B \to X_s\gamma$) and the rate of a free b-quark decay. The main features of our approach are the treatment of the…