Related papers: The $D\pi$ form factors from analyticity and unita…
The form factors of $B_{(s)}$ decays into P-wave excited charmed mesons (including $D^*_0(2300)$, $D_1(2430)$, $D_1(2420)$, $D^*_2(2460)$ and their strange counterparts, denoted generically as $D^{**}_{(s)}$) are systematically calculated…
We study the form factors for a heavy meson into the S-wave $K\pi/\pi\pi$ system with an invariant mass below 1~GeV. The mesonic final state interactions are described in terms of the scalar form factors, which are obtained from unitarized…
We investigate the factorization of different momentum modes that appear in matrix elements for exclusive B meson decays into light energetic particles for the specific case of B -> pi form factors at large pion recoil. We first integrate…
Form factors, as quantities involving both local operators and asymptotic particle states, contain information of both the spectrum of operators and the on-shell amplitudes. So far the studies of form factors have been mostly focused on the…
A method to construct free field realizations for the form factors of diagonal factorized scattering theories is described. Form factors are constructed from linear functionals over an associative `form factor algebra', which in particular…
Pion-kaon ($\pi K$) pairs occur frequently as final states in heavy-particle decays. A consistent treatment of $\pi K$ scattering and production amplitudes over a wide energy range is therefore mandatory for multiple applications: in…
We present a QCD study on $B, D\to\pi$ semileptonic transitions at zero momentum transfer and an estimate of magnitudes of the associated CKM matrix elements. Light cone sum rules (LCSRs) with chiral correlator are applied to calculate the…
We derive a new parametrization for the scalar pion form factors that allows us to analyze data over a large energy range via the inclusion of resonances, and at the same time to ensure consistency with the high-accuracy dispersive…
According to the heavy-quark flavour symmetry, the $B\to \pi, K$ transition form factors could be related to the corresponding ones of D-meson decays near the zero recoil point. With the recent precisely measured exclusive semileptonic…
We study the semileptonic decays of heavy mesons into light pseudoscalars by making use of dispersion relations. Constraints from heavy quark symmetry, chiral symmetry and perturbative QCD are implemented into a dispersive model for the…
The vector form factor f_+(t) of the semileptonic decay D -> K l nu, measured recently with a high accuracy, can be used to determine the strong coupling constant g_{D_s^* D K}. The latter is related to the normalised coupling \hat{g}…
The explicit one-dimensional integral representations for isovector nucleon form factors are constructed by solving the unitarity relations in terms of the pion form factor and imaginary parts of the t-channel p-wave $\pi N$-scattering…
We present a lattice determination of the vector and scalar form factors of the $D \to \pi(K) \ell \nu$ semileptonic decays, which are relevant for the extraction of the CKM matrix elements $|V_{cd}|$ and $|V_{cs}|$ from experimental data.…
The rare second-class decay mode of the $\tau$ into $\eta\pi\nu$ could be observed for the first time at Belle II. It is important to try to derive a reliable evaluation of the branching fraction and of the energy distribution of this mode…
The description of large-recoil heavy-to-light meson form factors is reviewed in the framework of soft-collinear effective theory. At leading power in the heavy quark expansion, three classes of approximate symmetry relations arise. The…
We calculate the $B\to P$, $B\to V$ (P: light pseudoscalar meson, V light vector meson) form factors in the large-recoil limit in perturbative QCD approach, including both the vector (axial vector) and tensor operators. In general there are…
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…
We calculate the $B\to\pi,\rho$ transition form factors in the framework of perturbative QCD to leading power of $1/M_B$, $M_B$ being the $B$ meson mass. We explain the basic principle by discussing the pion electromagnetic form factor. It…
Decay amplitudes of D(D_s)->f0(980)X, X=pi, K, are compared to experimental branching ratios with the aim of singling out the poorly known D->f0(980) transition form factor in these amplitudes. Since the other elements of the amplitudes are…
We present our calculation of D \to pi and D \to K semileptonic form factors in Nf = 2+1 lattice QCD. We simulate three lattice cutoffs 1/a \sim 2.5, 3.6 and 4.5 GeV with pion masses as low as 230 MeV. The M\"obius domain-wall action is…