Quantum loops in the Resonance Chiral Theory: improving the vector form factor

Quantum loops in the Resonance Chiral Theory are needed to improve the implementation of non-perturbative QCD. Furthermore, the one-loop computations can predict chiral low-energy couplings at next-to-leading order, a very appealing task. We present a first calculation of the vector form factor of the pion at subleading order in the 1/N_C expansion. From the analysis of the result at large energies we justify the requirement of considering short-distance constraints from form factors with resonances in the final state. The long-distance limit of our results allows to get a next-to-leading order estimate of \ell_6.Comment: Talk given at the International Workshop e+e- Collisions from phi to J/psi, 27th February-2nd March (2006), Novosibirsk (Russia

Enhancement of collagen deposition and cross-linking by coupling lysyl oxidase with bone morphogenetic protein-1 and its application in tissue engineering

Cultured cell-derived extracellular matrices (ECM)-based biomaterials exploit the inherent capacity of cells to create highly sophisticated supramolecular assemblies. However, standard cell culture conditions are far from ideal given the fact that the diluted microenvironment does not favor the production of ECM components, a circumstance particularly relevant for collagen. An incomplete conversion of procollagen by C-proteinase/bone morphogenetic protein 1 (BMP1) has been proposed to severely limit in vitro collagen deposition. BMP1 also catalyzes the proteolytic activation of the precursor of the collagen cross-linking enzyme, lysyl oxidase (LOX) to yield the active form, suggesting a deficit in cross-linking activity under standard conditions. We hypothesized that the implementation of fibroblast cultures with LOX and BMP1 may be an effective way to increase collagen deposition. To test it, we have generated stable cell lines overexpressing LOX and BMP1 and studied the effect of supernatants enriched in LOX and BMP1 on collagen synthesis and deposition from fibroblasts. Herein, we demonstrate that the supplementation with LOX and BMP1 strongly increased the deposition of collagen onto the insoluble matrix at the expense of the soluble fraction in the extracellular medium. Using decellularization protocols, we also show that fibroblast-derived matrices regulate adipogenic and osteogenic differentiation of human mesenchymal stem cells (MSC), and this effect was modulated by LOX/BMP1. Collectively, these data demonstrate that we have developed a convenient protocol to enhance the capacity of in vitro cell cultures to deposit collagen in the ECM, representing this approach a promising technology for application in tissue engineeringTis work was supported by grants from Ministerio de Economía y Competitividad (Plan Nacional de I+D+I: SAF2012-34916, and SAF2015-65679-R to F.R-P

One-loop Renormalization of Resonance Chiral Theory with Scalar and Pseudoscalar Resonances

The divergent part of the generating functional of the Resonance Chiral Theory is evaluated up to one loop when one multiplet of scalar an pseudoscalar resonances are included and interaction terms which couple up to two resonances are considered. Hence we obtain the renormalization of the couplings of the initial Lagrangian and, moreover, the complete list of operators that make this theory finite, at this order.Comment: 4 pages, no figures. Talk given at the High-Energy Physics International Conference on Quantum Chromodynamics, 2-9 July (2005), Montpellier (France). To appear in the Proceeding

Renormalization group equations in resonance chiral theory

The use of the equations of motion and meson field redefinitions allows the development of a simplified resonance chiral theory lagrangian: terms including resonance fields and a large number of derivatives can be reduced into corresponding O(p2) resonance operators, containing the lowest possible number of derivatives. This is shown by means of the explicit computation of the pion vector form-factor up to next-to-leading order in 1/Nc. The study of the renormalization group equations for the corresponding couplings demonstrates the existence of an infrared fixed point in the resonance theory. The possibility of developing a perturbative 1/Nc expansion in the slow running region around the fixed point is shown here.Comment: 6 pages, 3 figures. Final version as published. References added. Extended explanations. The interrelation between the IR fixed point and the UV constraints has been further studie

Renormalizable Sectors in Resonance Chiral Theory: S -> pi pi Decay Amplitude

We develop a resonance chiral theory without any a priori limitation on the number of derivatives in the hadronic operators. Through an exhaustive analysis of the resonance lagrangian and by means of field redefinitions, we find that the number of independent operator contributing to the S -> pi pi decay amplitude is finite: there is only one single-trace operator (the cd term) and three multi-trace terms. The deep implication of this fact is that the ultraviolet divergences that appear in this amplitude at the loop level can only appear through these chiral invariant structures. Hence, a renormalization of these couplings renders the amplitude finite.Comment: 4 page

On the structure of two-point Green-functions at next-to-leading order in 1/Nc

The structure of the two-point QCD Green-functions is studied in this note in the limit of large number of colours. Their general form at next-to-leading order in 1/Nc is derived keeping the infinite resonance summation and without relying on a particular realization of the hadronic action. It is found that the contributions from chiral operators without resonance fields of order p^4 or higher are irrelevant for the computation of the correlators and, hence, they can be dropped at the beginning of the calculation. The possibility of a more general cancelation of these local terms at the level of the generating functional is discussed.Comment: 6 pages, 1 figur

Vanishing chiral couplings in the large-N_C resonance theory

The construction of a resonance theory involving hadrons requires implementing the information from higher scales into the couplings of the effective Lagrangian. We consider the large-Nc chiral resonance theory incorporating scalars and pseudoscalars, and we find that, by imposing LO short-distance constraints on form factors of QCD currents constructed within this theory, the chiral low-energy constants satisfy resonance saturation at NLO in the 1/Nc expansion.Comment: 5 pages, 2 figures. Version published in Physical Review D. Some equations to facilitate the discussion have been adde

Current correlators and form factors in the resonance region

Within Resonance Chiral Theory and in the context of QCD current correlators at next-to-leading order in 1/N(C), we have analyzed the two-body form factors which include resonances as a final state . The short-distance constraints have been studied. One of the main motivations is the estimation of the chiral low-energy constants at subleading order, that is, keeping full control of the renormalization scale dependence. As an application we show the resonance estimation of some coupling, L(10)(mu_0)=(-4.4 \pm 0.9)10^{-3} and C(87)(mu_0)=(3.1 \pm 1.1)10^{-5}.Comment: Talk given at the 14th International Quantum Chromodynamics Conference, 7-12th July (2008), Montpellier (France

Pion and Kaon Decay Constants: Lattice vs. Resonance Chiral Theory

The Lattice results for the pion and kaon decay constants are analysed within the Resonance Chiral Theory framework in the large NC limit. The approximately linear behaviour of the observable at large light-quark mass is explained through the interaction with the lightest multiplet of scalar resonances. The analysis of the Lattice results allows to obtain the resonance mass MS=1049 +- 25 MeV and the Chiral Perturbation Theory parameters at leading order in 1/NC.Comment: 10 pages, 2 figure

Інформаційна культура й професійно-особистісний розвиток майбутнього вчителя історії

(uk) У статті розглядається ціннісно-мотиваційний компонент та прояв індивідуальності в структурі інформаційної культури майбутнього вчителя історії.(ru) В статье рассматривается ценностно-мотивационный компонент и проявление индивидуальности в структуре информационной культуры будущего учителя истории