Lattice quark masses: a non-perturbative measurement

We discuss the renormalization of different definitions of quark masses in the Wilson and the tree-level improved SW-Clover fermionic action. For the improved case we give the correct relationship between the quark mass and the hopping parameter. Using perturbative and non-perturbative renormalization constants, we extract quark masses in the \MSbar scheme from Lattice QCD in the quenched approximation at $\beta=6.0$, $\beta=6.2$ and $\beta=6.4$ for both actions. We find: \bar{m}^{\MSbar}(2 GeV)=5.7 \pm 0.1 \pm 0.8 MeV, m_s^{\MSbar}(2GeV)= 130 \pm 2 \pm 18 MeV and m_c^{\MSbar}(2 GeV) = 1662\pm 30\pm 230 MeV.Comment: 21 pages, 4 figures, typos corrected, no result change

Quark masses and the chiral condensate with a non-perturbative renormalization procedure

We determine the quark masses and the chiral condensate in the MSbar scheme at NNLO from Lattice QCD in the quenched approximation at beta=6.0, beta=6.2 and beta=6.4 using both the Wilson and the tree-level improved SW-Clover fermion action. We extract these quantities using the Vector and the Axial Ward Identities and non-perturbative values of the renormalization constants. We compare the results obtained with the two methods and we study the O(a) dependence of the quark masses for both actions.Comment: LATTICE98(spectrum), 3 pages, 1 figure, Edinburgh 98/1

Combined Relativistic and static analysis for all Delta B=2 operators

We analyse matrix elements of Delta B=2 operators by combining QCD results with the ones obtained in the static limit of HQET. The matching of all the QCD operators to HQET is made at NLO order. To do that we have to include the anomalous dimension matrix up to two loops, both in QCD and HQET, and the one loop matching for all the Delta B=2 operators. The matrix elements of these operators are relevant for the prediction of the B-\bar B mixing, B_s meson width difference and supersymmetric effects in Delta B=2 transitions.Comment: 3 pages, 1 figure. Lattice2001(heavyquark

Experimental and computational study of the effect of temperature on the electro-polymerization process of Thiophene

Temperature effect on the nucleation and growth mechanisms (NGM) of poly(thiophene) (PTh) was investigated through experimental and computational tools. The computational simulation method was based on a kinetic Monte Carlo algorithm. It reproduced key processes such as diffusion, oligomerization, and the precipitation of oligomers onto the electrode surface. Electrochemical synthesis conditions at temperatures between 263 and 303 K were optimized. The deconvolution of the i-t transients reflected two contributions: a progressive nucleation with three-dimensional growth controlled by diffusion and the other by charge transfer, PN3Ddif and PN3Dct, respectively. As temperature decreased, a diminution of the charge associated to each contribution was observed and the nucleation induction time increased. Experimental and computational evidence indicated that temperature does not change the nucleation and growth mechanism (NGM). This effect was ascribed to kinetic factors rather than to film conductivity. This work contrasts simulation and experimental evidence and demonstrates how computational simulations can help to understand the electrochemical process of conducting polymers formation.Fil: Camarada, María Belén. Pontificia Universidad Católica de Chile; Chile. Universidad de Talca; ChileFil: Romero, M.. Pontificia Universidad Católica de Chile; ChileFil: Gimenez, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Schmickler, Wolfgang. Universitat Ulm; AlemaniaFil: del Valle, M. A.. Pontificia Universidad Católica de Chile; Chil

Teaching Nanoscience and thinking nano at the macroscale: Nanocapsules of wisdom

One of the challenges for Nanotechnology is education, which is considered as a bottleneck for Nanotechnology development and implementation. This work contributes to nanoscale education by designing a wide variety of cutting-edge documentaries which assist high-educational level students in learning the underlying concepts of Nanoscience, the last advances and furure prospects. In addition, documentaries seek to bring and disseminate the scientific activity of Nanotechnology to society. In this sense, the secondary goals of the proposed approach nanotech activity are: 1) Transfer of knowledge generated in the nanotechnology field and 2) The promotion of scientific culture and innovation between the public objectives. Based on the results observed in students's assessment and You Tube metrics, it was concluded that the developed of nanoscale based documentaries enabled a fast and efficent comprehension of complex concepts related to Nanoscience and Nanotechnology. In addition, the opinion of You Tube audience is highly promising and shows that You Tube and documentaries are an excellent channel to disseminate Nanoscience to society

Non-perturbative Renormalization of the Complete Basis of Four-fermion Operators and B-parameters

We present results on the B-parameters $B_K$, $B^{3/2}_7$ and $B^{3/2}_8$, at $\beta=6.0$, with the tree-level Clover action. The renormalization of the complete basis of dimension-six four-fermion operators has been performed non-perturbatively. Our results for $B_K$ and $B^{3/2}_7$ are in reasonable agreement with those obtained with the (unimproved) Wilson action. This is not the case for $B^{3/2}_8$. We also discuss some subtleties arising from a recently proposed modified definition of the B-parameters.Comment: Talk presented at Lattice '97, Edinburgh (UK), July 1997. LaTeX 3 pages, uses espcrc