Related papers: Two-point function of strangeness-carrying vector-…
We calculate the correlator between two external vector-currents having the quantum-numbers of a charged kaon. We give the renormalized expression to two loops in standard chiral perturbation theory in the isospin limit, which, as a…
We perform a calculation of the isospin and hypercharge vector current propagators ($\Delta_{V33}^{\mu\nu}(q^2)$ and $\Delta_{V88}^{\mu\nu}(q^2)$) to two loops in chiral perturbation theory. The analysis is carried out with straightforward…
The isospin-breaking correlator of the product of flavor octet vector currents, $V^3_\mu$ and $V^8_\nu$, $\Pi^{38}_{\mu\nu}(q^2)$ is computed to next-to-next- to-leading (two-loop) order in Chiral Perturbation Theory. Large corrections to…
We perform a calculation of the isospin and hypercharge axialvector current propagators to two loops in SU(3)xSU(3) chiral perturbation theory. A large number of order p^6 divergent counterterms are fixed, and complete two-loop renormalized…
We calculate vector-vector correlation functions at two loops using partially quenched chiral perturbation theory including finite volume effects and twisted boundary conditions. We present expressions for the flavor neutral cases and the…
The mixed-isospin vector current correlator, $\langle 0\vert T(V^\rho_\mu V^\omega_\nu )\vert 0\rangle$ is evaluated using both QCD sum rules and Chiral Perturbation Theory (ChPT) to one-loop order. The sum rule treatment is a modification…
We compute the two-point correlator between left-handed flavour charges, and the three-point correlator between two left-handed charges and one strangeness violating \Delta I=3/2 weak operator, at next-to-leading order in finite volume…
We calculate, within massless QCD, a two-point correlator of nonlocal (composite) vector quark currents with arbitrary-length chains of the simplest fermion loops being inserted into gluon lines. Within the large $n_f$ (or large $\beta_0$)…
In this work we calculate the four-point correlation function of vector quark currents of QCD via holographic QCD model. Computing the correlator we take into account the exchange of vector and axial vector bosons and dilaton in the bulk.…
We consider two-point correlators in SU(N) gauge theories on R4 with N=2 supersymmetry and Nf massless hypermultiplets in the fundamental representation. Using localization on S4, we compute the leading perturbative corrections to the…
The renormalization of chiral perturbation theory is carried out to next-to-next-to-leading order in the meson sector. We calculate the divergent part of the generating functional of Green functions of quark currents to O(p^6) for chiral…
We calculate the vector and scalar form factors of the pion to two loops in Chiral Perturbation Theory. We estimate the unknown O(p^6) constants using resonance exchange. We make a careful comparison to the available data and determine two…
Two-loop corrections for the <VVA> correlator of the singlet axial and vector currents in QCD are calculated in the chiral limit for arbitrary momenta. Explicit calculations confirm the non-renormalization theorems derived recently by…
We present a calculation of the leading two-loop corrections to the axial-vector coupling constant $g_A$ in two covariant versions of two-flavor baryon chiral perturbation theory. Taking the low-energy constants from a combined analysis of…
Using quenched chiral perturbation theory, we compute the long-distance behaviour of two-point functions of flavour non-singlet axial and vector currents in a finite volume, for small quark masses, and at a fixed gauge-field topology. We…
Chiral perturbation theory in the two-flavour sector allows one to analyse Green functions in QCD in a limit where the strange quark mass is considered to be large in comparison to the external momenta and to the light quark masses. In this…
Chiral perturbation theory in the two--flavour sector allows one to analyse Green functions in QCD in the limit where the strange quark mass is considered to be large in comparison to the external momenta and to the light quark masses m_u…
To check the consistency of positivity requirements for the two-point correlation function of the topological charge density, which were identified in a previous paper, we are computing perturbatively this two-point correlation function in…
Using quenched and unquenched chiral perturbation theory we compute vector and axial current two-point functions at finite volume and fixed gauge field topology, in the so-called \epsilon-regime of QCD. A comparison of these results with…
We present a general method that allows to estimate the low-energy constants of Chiral Perturbation Theory up to next-to-leading corrections in the 1/N(C) expansion, that is, keeping full control of the renormalization scale dependence. As…