Related papers: Partial waves and large $N_C$ resonance sum rules
The improved light-cone QCD sum rules by using chiral current correlator is systematically reviewed and applied to the calculation of all the heavy-to-light form factors, including all the semileptonic and penguin ones. By choosing suitable…
A Roy equation analysis of the available $\pi\pi$ phase shift data is performed with the $I=0$ S- wave scattering length $a^0_0$ in the range predicted by the one-loop standard chiral perturbation theory. A suitable dispersive framework is…
In-medium sum rules following from the chiral charge algebra of QCD are reviewed, and new sum rules are derived. The new sum rules relate the I^G(J^{PC})=1^-(0^{++}) excitations (quantum numbers of a_0(980)) to the scalar and isovector…
Interactions of $a_2, K^*_2, f_2$ and $f_2'$ tensor-mesons with low-energy $\pi, K, \eta, \eta'$ pseudo-scalar mesons are constrained by chiral symmetry. We derive a chiral Lagrangian of tensor mesons in which the tensor mesons are treated…
The electromagnetic contribution to the $K^+ - K^0$ mass difference is calculated in the $1/N_c$ approach including the $SU(3)$ breaking contributions due to a non-zero strange quark mass. The short-distance contribution can be…
The QCD sum rule approach is employed in order to study chiral properties of positive- and negative-parity nucleon resonances. It is pointed out that nucleons with an ``exotic'' chiral property, which can be represented by local five-quark…
Gaussian sum-rules, which are related to a two-parameter Gaussian-weighted integral of a hadronic spectral function, are able to examine the possibility that more than one resonance makes a significant contribution to the spectral function.…
Non Efimovian $N$-body resonances are investigated in the regime of a large two-body s wave scattering length. In view of a universal description of low-energy bound and quasi-bound states, a contact model is introduced. The modeling…
In this work, we perform the one-loop calculation of the scalar and pseudoscalar form factors in the framework of U(3) chiral perturbation theory with explicit tree level exchanges of resonances. The meson-meson scattering calculation from…
In the large $N_c$ approximation to $QCD$, the leading $\pp$ scattering amplitude is expressed as the sum of an infinite number of tree diagrams. We investigate the possibility that an adequate approximation at energies up to somewhat more…
We review recent studies of light scalar meson properties by means of unitarization techniques, obtained from dispersion theory, and applied to the Chiral Perturbation Theory expansion. In particular, light scalars do not follow the N_c…
We have performed fits of the pseudoscalar masses and decay constants, from a variety of RBC-UKQCD domain wall fermion ensembles, to $SU(2)$ partially quenched chiral perturbation theory at next-to leading order (NLO) and next-to-next-to…
A proper way of subtracting the continuum contributions in light-cone QCD sum rules (LCQSR) is demonstrated. Specifically, we calculate the continuum corresponding to a typical OPE appearing in LCQSR by properly combining the double…
The Drell-Hearn-Gerasimov and Bjorken sum rules are special examples of dispersive sum rules for the spin-dependent structure function G_1(\nu, Q^2) at Q^2=0 and \infty. We generalize these sum rules through studying the virtual-photon…
We present a set of sum rules relating the low-energy light-by-light scattering to integrals of \gamma\gamma-fusion cross sections and use them to study the hadronic contributions.
The $SU(3)$ chiral effective lagrangian at next-to-leading order is applied to the S-wave meson-baryon interaction in the energy range around the $\eta N$ threshold. Potentials are derived from this lagrangian and used in a coupled channel…
In this work the low energy kaon-hyperon interaction is studied with nonlinear chiral invariant Lagragians considering kaons, hyperons, and the corresponding resonances in the intermediate states. We show the basic formalism to calculate…
We analyze quark-mass and $1/N_c$ corrections to all of the radiative transitions between the vector-meson nonet and the pseudoscalar-meson nonet within a chiral effective Lagrangian approach. We perform fits of the available coupling…
We extend our Wilsonian renormalization group (RG) analysis on the pionless nuclear effective theory (NEFT) in the two-nucleon sector in two ways; on the one hand, (1) we enlarge the space of operators up to including those of…
We re-examine the use of sum rules in the extraction of light quark masses and discuss a number of potential problems with existing analyses. The most important issue is that of the overall normalization of the hadronic spectral functions…