Related papers: Approximating chiral SU(3) amplitudes
We compute the O(1/M,m_s) heavy quark and SU(3) corrections to B_s -> D_s e nu form factors. In the limit of vanishing light quark mass, B_s -> D_s e nu form factors are given in terms of the the B -> D e nu form factors, the leading order…
Lattice $SU(N)\times SU(N)$ chiral models are analyzed by strong and weak coupling expansions and by numerical simulations. $12^{th}$ order strong coupling series for the free and internal energy are obtained for all $N\geq 6$. Three loop…
The confinement mechanism proposed earlier by the author is employed for to compute the decay constants $f_P$ corresponding to leptonic decays $P\to l^\pm+\nu_l$, $l=\mu, e$, where $P$ stands for any meson from $\pi^\pm$, $K^\pm$. For this…
We discuss the critical behaviour of strongly interacting matter close to the QCD phase transition. Emphasis is put on a presentation of results from lattice calculations that illustrate deconfining as well as chiral symmetry restoring…
We examine low energy limit of $U(3)_L\times U(3)_R$ chiral theory of mesons through integrating out fields of vector and axial-vector mesons. The effective lagrangian for pseudoscalar mesons at $O(p^4)$ has been obtained, and five low…
We study the decays of $B_{(s)}$ mesons into light pseudoscalar mesons under the $SU(3)$ flavour symmetry. Assuming exact $SU(3)$ symmetry at the level of the amplitudes leads to a simple parameterization. Using the available experimental…
We construct a few parameter approximate fixed point action for SU(2) pure gauge theory and subject it to scaling tests, via Monte Carlo simulation. We measure the critical coupling for deconfinement for lattices of temporal extent $N_t=2$,…
Flavor SU(3) symmetry, including $30\%$ first order SU(3) breaking, has been shown to describe adequately a vast amount of data for charmed meson decays to two pseudoscalar mesons and to a vector and a pseudoscalar meson. We review a recent…
Anisotropic lattice spacings are mandatory to reach the high temperatures where chiral symmetry is restored in the strong coupling limit of lattice QCD. Here, we propose a simple criterion for the nonperturbative renormalisation of the…
The B-meson decay constant fB has been calculated from unquenched lattice QCD in the unphysical region. For extrapolating the lattice data to the physical region, we propose a phenomenological functional form based on the effective chiral…
From an accurate determination of the inter-quark potential, one can study the running coupling constant for a range of $R$-values and hence estimate the scale $\Lambda_{\overline{\rm MS}}$. Detailed results are presented for $SU(3)$ pure…
A representation of the two-loop contribution to the pion decay constant in $SU(3)$ chiral perturbation theory is presented. The result is analytic upto the contribution of the three (different) mass sunset integrals, for which an expansion…
We present an update of our project of computing the meson spectrum and decay constants in large-N QCD. The results are obtained in the quenched approximation with the Wilson fermion action for N = 2, 3, 4, 5, 6, 7 and 17 and extrapolated…
The sector of decay constants of the octet of light pseudoscalar mesons in the framework of 'resummed' $SU(3)$ chiral perturbation theory is investigated. A theoretical prediction for the decay constant of $\eta$-meson is compared to a…
One can analyze the hadronic decay amplitudes for $B\to PP$ decays using flavor SU(3) symmetry in different ways, such as the algebraic and quark diagram approaches. We derive specific relations between these two sets of amplitudes. In the…
We determine chiral loop corrections to the B meson decay amplitudes to positive and negative parity charmed mesons within a framework which combines heavy quark and chiral symmetries. We find that corrections due to states of opposite…
The relativistic chiral SU(3) Lagrangian is used to describe kaon-nucleon scattering imposing constraints from the pion-nucleon sector and the axial-vector coupling constants of the baryon octet states. We solve the covariant…
The chiral symmetry at finite lattice spacing of Ginsparg-Wilson fermionic actions constrains the renormalization of the lattice operators; in particular, the topological susceptibility does not require any renormalization, when using a…
We fit the three finestructure constants of the Standard Model with three, in first approximation theoretically estimable parameters, 1) a "unifiedscale",turning out not equal to the Planck scale and thus only estimable by a very…
Using recent precise hadronic tau-decay data on the V-A spectral function, and general properties of QCD such as analyticity, the operator product expansion and chiral perturbation theory, we get accurate values for the QCD chiral order…