On the extraction of spectral densities from lattice correlators

Hadronic spectral densities are important quantities whose non-perturbative knowledge allows for calculating phenomenologically relevant observables, such as inclusive hadronic cross-sections and non-leptonic decay-rates. The extraction of spectral densities from lattice correlators is a notoriously difficult problem because lattice simulations are performed in Euclidean time and lattice data are unavoidably affected by statistical and systematic uncertainties. In this paper we present a new method for extracting hadronic spectral densities from lattice correlators. The method allows for choosing a smearing function at the beginning of the procedure and it provides results for the spectral densities smeared with this function together with reliable estimates of the associated uncertainties. The same smearing function can be used in the analysis of correlators obtained on different volumes, such that the infinite volume limit can be studied in a consistent way. While the method is described by using the language of lattice simulations, in reality it is completely general and can profitably be used to cope with inverse problems arising in different fields of research.Comment: 15 pages, 14 figures. Updated to match published versio

Spin Signatures of Photogenerated Radical Anions in Polymer-[70]Fullerene Bulk Heterojunctions: High Frequency Pulsed EPR Spectroscopy

Charged polarons in thin films of polymer-fullerene composites are investigated by light-induced electron paramagnetic resonance (EPR) at 9.5 GHz (X-band) and 130 GHz (D-band). The materials studied were poly(3-hexylthiophene) (PHT), [6,6]-phenyl-C61-butyric acid methyl ester (C60-PCBM), and two different soluble C70-derivates: C70-PCBM and diphenylmethano[70]fullerene oligoether (C70-DPM-OE). The first experimental identification of the negative polaron localized on the C70-cage in polymer-fullerene bulk heterojunctions has been obtained. When recorded at conventional X-band EPR, this signal is overlapping with the signal of the positive polaron, which does not allow for its direct experimental identification. Owing to the superior spectral resolution of the high frequency D-band EPR, we were able to separate light-induced signals from P+ and P- in PHT-C70 bulk heterojunctions. Comparing signals from C70-derivatives with different side-chains, we have obtained experimental proof that the polaron is localized on the cage of the C70 molecule

Influencia de las percepciones a las importaciones en la liquidez de la empresa Regenorsa E.I.R.L Distrito de Trujillo en el año 2015

La presente investigación ha sido realizado en base a la creación de los pagos adelantados del impuesto general a las ventas, que se creó con el fin de disminuir la evasión tributaria con respecto al IGV que se presentaba en muchos sectores de nuestra economía, sin embargo su creación ha conllevado a muchas empresas a lidiar con la falta de liquidez, debido a que estos pagos como su mismo nombre lo dice se realizan por adelantado. Con respecto a nuestro tema de investigación, la presente ha sido realizada en base a los pagos adelantados del Impuesto General a las Ventas por concepto de percepciones a las importaciones de la empresa REGENORSA E.I.R.L., donde se ha recopilado información correspondiente al año 2015, utilizando información verídica de los estados financieros, documentación, etc., los cuales luego de ser analizadas, interpretadas y comparadas, reflejan el efecto que produce la aplicación de este régimen del IGV, con respecto a la liquidez que posee la empresa, para ello se ha hecho uso de indicadores financieros, tales como. Los ratios o índices de liquidez. Luego de la aplicación de los diferentes métodos de investigación y recolección de datos, se llegó a la conclusión de que las percepciones a las importaciones afectan negativamente a la liquidez de la empresa REGENORSA E.I.R.L., obligando a que busque otros métodos de financiación o renegociación que le ayude a soportar dichos problemas.This research has been carried out based on the creation of advance payments from the general sales tax, which was created in order to reduce tax evasion with respect to IGV that appeared in many sectors of our economy, yet their creation has led many companies to deal with the lack of liquidity, because these payments as its name says it is made in advance. With respect to our research topic, this has been carried out based on advance payments of General Sales Tax on account of perceptions imports REGENORSA E.I.R.L. Company, which has compiled information for the year 2015, using truthful reporting of financial statements, documentation, etc., which after being analyzed, interpreted and compared, reflecting the effect of the application of this system of VAT, with regard to liquidity held by the company, for it has been done use of financial indicators such as. The liquidity ratios. After application of the different research methods and data collection, it was concluded that perceptions imports adversely affect the liquidity of the company REGENORSA EIRL, forced to seek other financing methods or renegotiation that help support such problems

QCD with light Wilson quarks on fine lattices (I): first experiences and physics results

Recent conceptual, algorithmic and technical advances allow numerical simulations of lattice QCD with Wilson quarks to be performed at significantly smaller quark masses than was possible before. Here we report on simulations of two-flavour QCD at sea-quark masses from slightly above to approximately 1/4 of the strange-quark mass, on lattices with up to 64x32^3 points and spacings from 0.05 to 0.08 fm. Physical sea-quark effects are clearly seen on these lattices, while the lattice effects appear to be quite small, even without O(a) improvement. A striking result is that the dependence of the pion mass on the sea-quark mass is accurately described by leading-order chiral perturbation theory up to meson masses of about 500 MeV.Comment: TeX source, 17 pages, figures include

Eco-Friendly Methodology to Prepare N-Heterocycles Related to Dihydropyridines: Microwave-Assisted Synthesis of Alkyl 4-Arylsubstituted-6-chloro-5-formyl-2-methyl-1,4-dihydropyridine-3-carboxylate and 4-Arylsubstituted-4,7-dihydrofuro[3,4-b]pyridine-2,5(1H,3H)-dione

Here we describe the efficient synthesis of alkyl 4-arylsubstituted-6-chloro-5-formyl-2-methyl-1,4-dihydropyridine-3-carboxylates and 4-arylsubstituted-4,7-dihydro-furo[3,4-b]pyridine-2,5(1H,3H)-diones via microwave-accelerated reaction of alkyl 4-arylsubstituted-2-methyl-6-oxo-1,4,5,6-tetrahydro-3-pyridinecarboxylates with the appropriate reagents. This eco-friendly approach to these valuable dihydropyridine derivatives does not involve the harsh or highly contaminating conditions common in classical heating and offers a reduction or even elimination of solvent use and recovery, simplification of the work-up procedures, facility of scale up, and low energy consumption, in addition to moderate to higher yields

QCD with light Wilson quarks on fine lattices (II): DD-HMC simulations and data analysis

In this second report on our recent numerical simulations of two-flavour QCD, we provide further technical details on the simulations and describe the methods we used to extract the meson masses and decay constants from the generated ensembles of gauge fields. Among the topics covered are the choice of the DD-HMC parameters, the issue of stability, autocorrelations and the statistical error analysis. Extensive data tables are included as well as a short discussion of the quark-mass dependence in partially quenched QCD, supplementing the physics analysis that was presented in the first paper in this series.Comment: TeX source, 35 pages, figures include

Balance hídrico superficial de la subcuenca El Sauce

El estudio consiste en el balance hidrológico de la unidad de subcuenca del Sauce, con el fin de valorar la disponibilidad del recurso hídrico, que sirva como herramienta en la toma de decisiones de instituciones y consumidores del recurso agua, caracteriza los parámetros morfométricos de la unidad de cuenca, de igual manera caracteriza los parámetros climáticos de la zona de estudio, calcula el balance hídrico superficial de la subcuenca del Sauc

Simulations of QCD and QED with C* boundary conditions

We present exploratory results from dynamical simulations of QCD in isolation, as well as QCD coupled to QED, with C* boundary conditions. In finite volume, the use of C* boundary conditions allows for a gauge invariant and local formulation of QED without zero modes. In particular we show that the simulations reproduce known results and that masses of charged mesons can be extracted in a completely gauge invariant way. For the simulations we use a modified version of the HiRep code. The primary features of the simulation code are presented and we discuss some details regarding the implementation of C* boundary conditions and the simulated lattice action