Related papers: $D^*D\pi$ form factor revisited
We study the $P\to\gamma\,\gamma^*$ ($P=\pi^0,\eta,\eta'$) transition form factors by means of the local-duality (LD) version of QCD sum rules. For the case of $\eta$ and $\eta'$, the conventional LD model provides a good description of the…
QCD sum rules for chiral partners in the open-charm meson sector are presented at nonzero baryon net density or temperature. We focus on the differences between pseudo-scalar and scalar as well as vector and axial-vector D mesons and derive…
We present the status of on-going calculations of the $K\to\pi l\nu$ and $D\to K(\pi) l\nu$ semileptonic form factors at $q^2=0$. These form factors are important for the determination of the CKM matrix elements $\lvert{V_{us}}\rvert$ and…
In this work, the transition form factors are calculated for the semileptonic $D_{(s)} \to A \ell^+ \nu$ where $A=a_{1}, b_{1}, K_{1}(1270,1400)$, i.e., $D^{+} \to a^{0}_{1} (b^{0}_{1}, K^{0}_{1}) \ell^+ \nu$, $D^{0} \to a^{-}_{1}…
We analyse the extraction of the bound-state form factor from vacuum-to-hadron correlator, which is the basic object for the calculation of hadron form factors in the method of light-cone sum rules in QCD. We study this correlator in…
The electric dipole form factor of the nucleon stemming from the QCD $\bar{\theta}$ term is calculated in chiral perturbation theory in leading order. To this order, the form factor originates from the pion cloud. Its momentum-dependence is…
In previous work Phys. Rev. D 107, 074507 (2023), we showed that form factors for radiative leptonic decays of pseudoscalar mesons can be determined efficiently and with high precision from lattice QCD using the ``3d method,'' in which…
2-point correlators of vector and axial currents, obtained from tau-decay data, are studied within the framework of perturbative QCD and Operator Product Expansion. Various sum rules, obtained from Borel transformation of the correlators in…
Rare exclusive $B_c^\ast \rightarrow D_{s}~l^+ l^-$ decays are analyzed in the framework of the three--point QCD sum rules approach. The two gluon condensate corrections to the correlation function are included and the form factors of this…
The method of light-cone QCD sum rules is applied to the calculation of the form factors of $\gamma^*\rho \to \pi$ and $\gamma^*\gamma \to \pi^0$ transitions. We consider the dispersion relation for the $\gamma^*(Q^2)\gamma^*(q^2) \to…
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…
Analyticity and unitarity techniques are employed to obtain bounds on the shape parameters of the scalar and vector form factors of semileptonic $K_{l3}$ decays. For this purpose we use vector and scalar correlators evaluated in pQCD, a low…
In this paper, the $D\to P(\pi, K)$ helicity form factors (HFFs) are studied by applying the QCD light-cone sum rule (LCSR) approach. The calculation accuracy is up to next-to-leading order (NLO) gluon radiation correction of twist-(2,3)…
We discuss the extraction of ground-state parameters, such as decay constants and form factors, from two- and three-point dispersive sum rules, making use of a quantum-mechanical potential model. This model provides a unique possibility to…
The off-shell pion electromagnetic form factors are explored with corresponding off-shell light-front wave functions modeled by constituent quark and anti-quark. We apply the Mandelstam approach for the microscopic computation of the form…
A consistent treatment of $B\rightarrow \pi l \nu$ decay is given on the light-front. The $B$ to $\pi$ transition form factors are calculated in the entire physical range of momentum transfer for the first time. The valence-quark…
We derive new QCD sum rules for $B\to D$ and $B\to D^*$ form factors. The underlying correlation functions are expanded near the light-cone in terms of $B$-meson distribution amplitudes defined in HQET, whereas the $c$-quark mass is kept…
Using partially twisted boundary conditions we compute the K->pi semi-leptonic form factors in the range of momentum transfers 0 <~ q^2 <= q^2_{max}=(mK-mpi)^2 in lattice QCD with N_f=2+1 dynamical flavours. In this way we are able to…
We study photon-meson transition formfactors of light mesons in the kinematics, where one photon is real and other is virtual. Dispersive approach to axial anomaly leads to the anomaly sum rule. The absence of corrections to it allows us to…
Using a recently developed three-point formalism within the method of QCD Sum Rules we determine the vacuum susceptibilities needed in the two-point formalism for the coupling of axial, vector, tensor and pseudoscalar currents to hadrons.…