The infrared dynamics of Minimal Walking Technicolor

We study the gauge sector of Minimal Walking Technicolor, which is an SU(2) gauge theory with nf=2 flavors of Wilson fermions in the adjoint representation. Numerical simulations are performed on lattices Nt x Ns^3, with Ns ranging from 8 to 16 and Nt=2Ns, at fixed \beta=2.25, and varying the fermion bare mass m0, so that our numerical results cover the full range of fermion masses from the quenched region to the chiral limit. We present results for the string tension and the glueball spectrum. A comparison of mesonic and gluonic observables leads to the conclusion that the infrared dynamics is given by an SU(2) pure Yang-Mills theory with a typical energy scale for the spectrum sliding to zero with the fermion mass. The typical mesonic mass scale is proportional to, and much larger than this gluonic scale. Our findings are compatible with a scenario in which the massless theory is conformal in the infrared. An analysis of the scaling of the string tension with the fermion mass towards the massless limit allows us to extract the chiral condensate anomalous dimension \gamma*, which is found to be \gamma*=0.22+-0.06.Comment: 29 pages, 16 figure

Finite volume effects in SU(2) with two adjoint fermions

Many evidences from lattice simulations support the idea that SU(2) with two Dirac flavors in the adjoint representation (also called Minimal Walking Technicolor) is IR conformal. A possible way to see this is through the behavior of the spectrum of the mass-deformed theory. When fermions are massive, a mass-gap is generated and the theory is confined. IR-conformality is recovered in the chiral limit: masses of particles vanish in the chiral limit, while their ratios stay finite. In order to trust this analysis one has to relay on the infinite volume extrapolation. We will discuss the finite volume effects on the mesonic spectrum, investigated by varying the size of the lattice and by changing the boundary conditions for the fields.Comment: Proceedings of Lattice 2011, 7 pages, 4 figure

The meson spectrum in large-N QCD

We present lattice results on the meson spectrum and decay constants in large-N QCD. The results are obtained in the quenched approximation for N = 2,3,4,5,6,7 and 17 and extrapolated to N = ∞. Xth Quark Confinement and the Hadron Spectrum

Topological susceptibility of SU(N) gauge theories at finite temperature

We investigate the large-N behavior of the topological susceptibility in four-dimensional SU(N) gauge theories at finite temperature, and in particular across the finite-temperature transition at Tc. For this purpose, we consider the lattice formulation of the SU(N) gauge theories and perform Monte Carlo simulations for N=4,6. The results indicate that the topological susceptibility has a nonvanishing large-N limit for T<Tc, as at T=0, and that the topological properties remain substantially unchanged in the low-temperature phase. On the other hand, above the deconfinement phase transition, the topological susceptibility shows a large suppression. The comparison between the data for N=4 and N=6 hints at a vanishing large-N limit for T>Tc.Comment: 9 pages, 2 figs, a few discussions added, JHEP in pres

Topological susceptibility in the SU(3) gauge theory

We compute the topological susceptibility for the SU(3) Yang--Mills theory by employing the expression of the topological charge density operator suggested by Neuberger's fermions. In the continuum limit we find r_0^4 chi = 0.059(3), which corresponds to chi=(191 +/- 5 MeV)^4 if F_K is used to set the scale. Our result supports the Witten--Veneziano explanation for the large mass of the eta'.Comment: Final version to appear on Phys. Rev. Let

The addition of polysaccharide gums to Aronia melanocarpa purees modulates the bioaccessibility of phenolic compounds and gut microbiota: A multiomics data fusion approach following in vitro digestion and fermentation

This study aimed to determine how the addition of gellan, guar, locust bean, and xanthan gums affected the polyphenol profile of Aronia melanocarpa puree and the human gut microbiota after in vitro gastrointestinal digestion and large intestine fermentation. The different gums distinctively affected the content and bioaccessibility of phenolics in Aronia puree, as outlined by untargeted metabolomics. The addition of locust bean gum increased the levels of low -molecular -weight phenolics and phenolic acids after digestion. Gellan and guar gums enhanced phenolic acids' bioaccessibility after fermentation. Interactions between digestion products and fecal bacteria altered the composition of the microbiota, with the greatest impact of xanthan. Locust bean gum promoted the accumulation of different taxa with health -promoting properties. Our findings shed light on the added -value properties of commercial gums as food additives, promoting a distinctive increase of polyphenol bioaccessibility and shifting the gut microbiota distribution, depending on their composition and structural features

Improved Lattice Spectroscopy of Minimal Walking Technicolor

We present a numerical study of spectroscopic observables in the SU(2) gauge theory with two adjoint fermions using improved source and sink operators. We compare in detail our improved results with previous determinations of masses that used point sources and sinks and we investigate possible systematic effects in both cases. Such comparison enables us to clearly assess the impact of a short temporal extent on the physical picture, and to investigate some effects due to the finite spatial box. While confirming the IR-conformal behaviour of the theory, our investigation shows that in order to make firm quantitative predictions, a better handle on finite size effects is needed.Comment: 33 pages, 30 figures, 18 table

Renormalization of circle diffeomorphism sequences and markov sequences

We show a one-to-one correspondence between circle diffeomorphism sequences that are C^{ 1+n}-periodic points of renormalization and smooth Markov sequences.We thank the financial support of LIAAD–INESC TEC through program PEst, USP-UP project, Faculty of Sciences, University of Porto, Calouste Gulbenkian Foundation, FEDER and COMPETE Programmes, PTDC/MAT/121107/2010 and Fundação para a Ciência e a Tecnologia (FCT). J. P.Almeida acknowledges the FCT support given through Grant SFRH/PROTEC/49754/2009

Repetibilidad y reproducibilidad de las medidas de tejidos in vivo efectuadas con ultrasonidos en ovejas adultas y sus correlaciones con la condición corporal

La evaluación de la condición corporal permite conocer el estado de reservas de los animales (Santucci et al., 1991; Delfa el al., 1995; Teixeira et al., 1995), siendo el espesor de los tejidos en la región esternal el punto de elección en caprinos tal como mostró Morand-Fehr et al. (1989). Este conocimiento permite adecuar la alimentación de los animales, no obstante esta metodología es muy susceptible a errores entre operadores (Evans, 1978). Así la substitución de esta técnica por otras más objetivas presenta interés práctico. Las medidas de ultrasonidos que permiten determinar las medidas de espesor de los tejidos, con elevada repetible edad y reproducibilidad, podrán ser una alternativa interesante

Age-related central regulation of orexin and NPY in the short-lived African killifish Nothobranchius furzeri

Orexin A (OXA) and neuropeptide Y (NPY) are two hypothalamic neuropeptides involved in the regulation of feeding behavior and food intake in all vertebrates. Accumulating evidences document that they undergo age-related modifications, with consequences on metabolism, sleep/wake disorders and progression of neurodegenerations. The present study addressed the age related changes in expression and distribution of orexin A (its precursor is also known as hypocretin\u2014HCRT) and NPY, and their regulation by food intake in the short-lived vertebrate model Nothobranchius furzeri. Our experiments, conducted on male specimens, show that: (a) HCRT and OXA and NPY mRNA and protein are localized in neurons of diencephalon and optic tectum, as well as in numerous fibers projecting through the entire neuroaxis, and are colocalized in specific nuclei; (b) in course of aging, HCRT and NPY expressing neurons are localized also in telencephalon and rhombencephalon; (c) HCRT expressing neurons increased slightly in the diencephalic area of old animals and in fasted animals, whereas NPY increased sharply; (d) central HCRT levels are not regulated neither in course of aging nor by food intake; and (e) central NPY levels are augmented in course of aging, and regulated by food intake only in young. These findings represent a great novelty in the study of central orexinergic and NPY-ergic systems in vertebrates', demonstrating an uncommon and unprecedented described regulation of these two orexigenic neuropeptides