NLO QCD corrections to the production of a weak boson pair associated by a hard jet

In this talk we discuss recent progress concerning precise predictions for the LHC. We give a status report of an application of the GOLEM method to deal with multi-leg one-loop amplitudes, namely the next-to-leading order QCD corrections to the process pp to V V + jet, where V is a weak boson W,Z.Comment: Talk at 2008 Rencontres de Moriond, QCD session, La Thuile, March 2007. Four page

The Regulation of Residential Tenancy Markets in Post-War Western Europe: An Economic Analysis

This paper provides an economic analysis of the post-war regulation of European tenancy markets. Two representative types of market regulation are analyzed: the introduction of compulsory duration clauses in tenancy contracts (as a means of protecting the tenant against eviction); and rent control policies. First, the study describes and analyzes the recent history of such regulations in Spain, Italy, Finland and the UK, in order to draw some general conclusions about the evolution of European institutions in recent decades. Their effects are then explored by adapting a theoretical model of tenancy markets. The results show that both rent control and compulsory duration clauses potentially entail negative effects for European tenancy markets as they may drive some participants out of the market. These effects are consistent with the trends observed during the latter half of the 20th century in several European countries.Rent control, Tenancy contracts, Compulsory terms

NLO QCD corrections to ZZ+jet production at hadron colliders

A fully differential calculation of the next-to-leading order QCD corrections to the production of Z-boson pairs in association with a hard jet at the Tevatron and LHC is presented. This process is an important background for Higgs particle and new physics searches at hadron colliders. We find sizable corrections for cross sections and differential distributions, particularly at the LHC. Residual scale uncertainties are typically at the 10% level and can be further reduced by applying a veto against the emission of a second hard jet. Our results confirm that NLO corrections do not simply rescale LO predictions.Comment: 15 pages, 4 figures, 4 tables; added 1 reference, version to appear in Phys. Lett.

The effect of institutions on European housing markets : an economic analysis

Durante el siglo XX y en especial en su segunda mitad, el mercado de alquiler ha ido perdiendo peso a favor de la vivienda en propiedad tanto en la economía española como en la del resto de países europeos. El gráfico R.1 muestra esta tendencia negativa en el peso del mercado del alquiler sobre el total de viviendas principales1 para algunas economías europeas en los años más recientes. En este contexto y si bien la reducción en el peso del mercado de alquiler (a favor del mercado de vivienda en propiedad) es un hecho común a la práctica totalidad de países, el caso español es especialmente extremo. El primer censo que recogió esta información (1970) ya indicaba que la proporción de vivienda principal en propiedad estaba en torno al 60% (tasa de propiedad del 63’4%). En el año 2008 era posible encontrar provincias españolas en las que la tasa de vivienda principal en propiedad superaba el 94% (Castellón, Soria o Lugo). Desde un punto de vista puramente económico, una fortaleza excesiva de la vivienda en propiedad genera algunas ineficiencias en el funcionamiento de la economía. Entre otros factores este efecto se debe a que una reducida tasa de alquiler puede acabar disminuyendo la movilidad de los trabajadores (Hardman e Ionnides, 1999, Barceló, 2006). De hecho se observa que las economías con una mayor tasa de alquiler, como Francia o Alemania, también muestran una mayor movilidad interregional (Maclennan et al. 1998, Barceló, 2006). Paralelamente, la literatura económica relaciona una baja movilidad con un mayor desempleo (Layard et al. 1991). Numerosos factores pueden haber afectado a los mercados inmobiliarios impulsando al alza el mercado de la vivienda en propiedad. Entre ellos y sobre todo para los últimos años cabe citar la reducción general de los tipos de interés (Blanco y Restoy, 2007) junto a la liberalización bancaria (Iacoviello y Minetti, 2003, Kumbhakar y Lozano-Vivas, 2004) o los aumentos en la renta per capita. Frente a estos factores, ampliamente estudiados en la literatura, otros factores que se podrían englobar como “institucionales” pueden también haber influenciado las tasas de alquiler y propiedad. Entre ellos, cabría citar la regulación de los mercados (las llamadas “instituciones formales”) y el funcionamiento del sistema judicial como medio de ejecución de los contratos y pactos realizados en esos mercados (las llamadas “instituciones de ejecución”). En ambos casos se puede afirmar que no han sido suficientemente estudiadas en cuanto a sus efectos en los mercados inmobiliarios. En consecuencia, esta tesis doctoral se centra en el análisis de los efectos de la regulación de los mercados inmobiliarios, en especial las normativas vigentes en los mercados de alquiler, que podrían haber introducido desincentivos relativamente importantes para los arrendadores de vivienda así como el efecto del buen o mal funcionamiento del sistema judicial a la hora de hacer cumplir los pactos y contratos efectuados en esos mercado

Is judicial inefficiency increasing the house property market weight in Spain? : evidence at the local level

Compared with the rest of the European countries the weight of the house property market in Spain is very high, which is consistent with the weakness of the tenancy market. In this context, it has often been argued that an inefficient judicial system, implying a cumbersome procedure to evict a non-paying tenant or simply needing a long period to execute a decision, may be an important determinant of the tenancy market weakness, as it constrains the effective supply by reducing the profitability of landlords. This research has studied this effect econometrically using a panel data approach and exploiting the differences in the judicial efficiency that exists among the Spanish provinces. After controlling for several other factors, this study concludes that the degree of inefficiency of the judicial system has a positive, although minor, impact on the differences in the property share among provinces in Spai

The impact of the efficacy of justice on business investment in Spain

Artículo de revistaOne of the main determinants of the level of dynamism of business investment is the efficacy of the legal system, as an essential element of the institutional framework of an economy. This article sets out an empirical approach to the impact of the efficacy of justice on the investment decisions of a sample of Spanish firms. Drawing on the cross-provincial heterogeneity in the court congestion rate, and how it changes over time, this analysis suggests there is a positive and significant correlation between efficacy in the civil justice system and business investment in Spain

32 Bin Near-Infrared Time-Multiplexing Detector with Attojoule Single-Shot Energy Resolution

We present two implementations of photon counting time-multiplexing detectors for near-infrared wavelengths, based on Peltier cooled InGaAs/InP avalanche photo diodes (APDs). A first implementation is motivated by practical considerations using only commercially available components. It features 16 bins, pulse repetition rates of up to 22 kHz and a large range of applicable pulse widths of up to 100 ns. A second implementation is based on rapid gating detectors, permitting deadtimes below 10 ns. This allows one to realize a high dynamic-range 32 bin detector, able to process pulse repetition rates of up to 6 MHz for pulse width of up to 200 ps. Analysis of the detector response at 16.5% detection efficiency, reveals a single-shot energy resolution on the attojoule level.Comment: 7 pages, 7 figure

Comparison of Bond Character in Hydrocarbons and Fullerenes

We present a comparison of the bond polarizabilities for carbon-carbon bonds in hydrocarbons and fullerenes, using two different models for the fullerene Raman spectrum and the results of Raman measurements on ethane and ethylene. We find that the polarizabilities for single bonds in fullerenes and hydrocarbons compare well, while the double bonds in fullerenes have greater polarizability than in ethylene.Comment: 7 pages, no figures, uses RevTeX. (To appear in Phys. Rev. B.

Centralized and Distributed Power Allocation for Max-Min Fairness in Cell-Free Massive MIMO

Cell-free Massive MIMO systems consist of a large number of geographically distributed access points (APs) that serve users by coherent joint transmission. Downlink power allocation is important in these systems, to determine which APs should transmit to which users and with what power. If the system is implemented correctly, it can deliver a more uniform user performance than conventional cellular networks. To this end, previous works have shown how to perform system-wide max-min fairness power allocation when using maximum ratio precoding. In this paper, we first generalize this method to arbitrary precoding, and then train a neural network to perform approximately the same power allocation but with reduced computational complexity. Finally, we train one neural network per AP to mimic system-wide max-min fairness power allocation, but using only local information. By learning the structure of the local propagation environment, this method outperforms the state-of-the-art distributed power allocation method from the Cell-free Massive MIMO literature

Litigation in Spain 2001-2010 : exploring the market for legal services

Existe evidencia empírica de que se da una asociación positiva entre el número de abogados por habitante y el número de litigios entre países. Por ejemplo, España cuenta con más litigios y más abogados por habitante que la mayoría de los países de la OCDE. ¿Cómo interpretar esta asociación? En este trabajo se analiza la variación de ambas variables en las provincias españolas durante el período 2001-2010 y, por medio de un enfoque econométrico de variables instrumentales, se ilustran algunas de las causas de la asociación estadística entre ellas y se comentan ciertas implicaciones de los resultadosThere is empirical evidence of a cross-country positive association between the number of lawyers per capita and the extent of litigation. For instance, Spain has more litigation and more lawyers per capita than most OECD countries. How should this association be interpreted? In this paper we analyse the variation in both variables across Spanish provinces during the period 2001-2010, by means of an instrumental variable approach, to shed some light on the sources of the statistical association between them. Finally, implications of the results are discusse