Overview of Spanish Tracking R&D for FLC

An overview of the present and foreseen R&D activities of the Spanish network for future accelerators aiming to participate in the design and construction of the forward tracker and vertex detectors of the Future Linear Colliders, is shown.Comment: 7 pages, 8 Figures, LCWS10 Conference Proceeding

Spectral energy distribution of hyperluminous infrared galaxies

Aims. The relationship between star formation and super-massive black hole growth is central to our understanding of galaxy formation and evolution. Hyperluminous infrared galaxies (HLIRG) are unique laboratories to investigate the connection between starburst (SB) and active galactic nuclei (AGN), because they exhibit extreme star-formation rates, and most of them show evidence of harbouring powerful AGN. Methods. Our previous X-ray study of a sample of HLIRG shows that the X-ray emission of most of these sources is dominated by AGN activity. To improve our estimate of the relative contribution of the AGN and SB emission to its total bolometric output, we have built multi-wavelength (from radio to X-rays) spectral energy distributions (SED) for these HLIRG and fitted standard empirical AGN and SB templates to these SED. Results. In broad terms, most sources are well fitted with this method, and we found AGN and SB contributions similar to those obtained by previous studies of HLIRG. We have classified the HLIRG SED into two groups, class A and class B. Class A HLIRG show a flat SED from the optical to the infrared energy range. Three out of seven class A sources can be modelled with a pure luminosity-dependent quasar template, while the rest of them require a type 1 AGN template and a SB template. The SB component is dominant in three out of four class A objects. Class B HLIRG show SED with a prominent and broad IR bump. These sources cannot easily be modelled with a combination of pure AGN and pure SB, they require templates of composite objects, suggesting that >∼50% of their emission comes from stellar formation processes. Conclusions. We propose that our sample is actually composed of three different populations: very luminous quasars (class A objects with negligible SB contribution), young galaxies going through their maximal star-formation period (class A objects with significant SB emission) and the high luminosity tail of the ultraluminous infrared galaxies population distribution (class B sources).We are grateful to the referee M. Rowan-Robinson for the constructive comments and suggestions that improved this paper. A.R. acknowledges support from a Universidad de Cantabria fellowship and from ASI grant n. ASI I/088/06/0. Financial support for A.R. and F.J.C. was provided by the Spanish Ministry of Education and Science, under projects ESP2003-00812 and ESP2006-13608-C02-01. FP acknowledges financial support under the project ASI INAF I/08/07/0. G.M. thanks the Ministerio de Ciencia e Innovación and CSIC for support through a Ramón y Cajal contract. This research made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This paper is based also on data from the VOSED tool at LAEFF. The 2.5 m Isaac Newton Telescope and its service programme are operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias

Divulgação em física de partículas: masterclasses internacionais concurso CERN-Beamline e o grupo internacional de divulgação em física de partículas

La red internacional de científicos y comunicadores IPPOG ("International Particle Physics Outreach Group") tiene como objetivo divulgar y educar en física de partículas. La estructura elemental de la materia y la dinámica que rige su comportamiento las muestra al gran público mediante diversas actividades que tratan de fortalecer la curiosidad por la cultura científica. En este artículo, que fué presentado en la Bienal de la Real Sociedad de Física celebrada en Gijón, en 2015, se muestra resumidamente una de sus actividades de mayor éxito, las Clases Magistrales Internacionales ("International Masterclasses") en Física de Partículas. Además se presenta una actividad desarrollada por el CERN para mantener el interés de estudiantes de enseñanza secundaria por la física que se desarrolla en las grandes instalaciones científicas, el concurso "CERN Beamline". Los miembros del IPPOG actúan en el mismo como colaboradores expertos.A rede internacional de cientistas e comunicadores IPPOG ("International Particle Physics Outreach Group") tem como objectivo a divulgação e educação em física de partículas. A estrutura elementar da matéria e a dinâmica que rege o seu comportamento são mostradas ao público em geral através de várias actividades que visam reforçar a curiosidade pela cultura científica. Este artigo, que foi apresentado na Bienal da Royal Physical Society realizada em Gijón em 2015, resume uma das suas actividades de maior sucesso, as Masterclasses Internacionais de Física de Partículas. Além disso, é apresentada uma actividade desenvolvida pelo CERN para manter o interesse dos estudantes do ensino secundário na física que tem lugar em grandes instalações científicas, o concurso "CERN Beamline". Os membros do IPPOG actuam como colaboradores peritos neste concurso

Modified spinning black holes

In the context of f(R) modified gravity theories we determine that the black holes existence is determined by the sign of a parameter dependent of the mass, the charge, the spin and the scalar curvature. We obtain the different astrophysical objects derived from the presence of different horizons. Thermodynamics for this kind of black holes is studied for negative values of the curvature, revealing that we can distinguish between two kind of BH: fast and slow

Measurement of the WW and WZ production cross section using final states with a charged lepton and heavy-flavor jets in the full CDF Run II data set

et al.We present a measurement of the total WW and WZ production cross sections in pp¯ collision at √s=1.96 TeV, in a final state consistent with leptonic W boson decay and jets originating from heavy-flavor quarks from either a W or a Z boson decay. This analysis uses the full data set collected with the CDF II detector during Run II of the Tevatron collider, corresponding to an integrated luminosity of 9.4 fb-1. An analysis of the dijet mass spectrum provides 3.7σ evidence of the summed production processes of either WW or WZ bosons with a measured total cross section of σWW+WZ=13.7±3.9 pb. Independent measurements of the WW and WZ production cross sections are allowed by the different heavy-flavor decay patterns of the W and Z bosons and by the analysis of secondary-decay vertices reconstructed within heavy-flavor jets. The productions of WW and of WZ dibosons are independently seen with significances of 2.9σ and 2.1σ, respectively, with total cross sections of σWW=9.4±4.2 pb and σWZ=3.7-2.2+2.5 pb. The measurements are consistent with standard-model predictions.This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation; the A. P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the Korean World Class University Program, the National Research Foundation of Korea; the Science and Technology Facilities Council and the Royal Society, UK; the Russian Foundation for Basic Research; the Ministerio de Ciencia e Innovación, and Programa Consolider-Ingenio 2010, Spain; the Slovak R&D Agency; the Academy of Finland; and the Australian Research Council (ARC).Peer Reviewe

High-precision measurement of the W boson mass with the CDF II detector

The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. The Higgs boson was the last missing component of the model. After observation of the Higgs boson, a measurement of the W boson mass provides a stringent test of the model. We measure the W boson mass, MW, using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at a 1.96 tera–electron volt center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. A sample of approximately 4 million W boson candidates is used to obtain MW=80,433.5±6.4stat±6.9syst=80,433.5±9.4 MeV/c2 , the precision of which exceeds that of all previous measurements combined (stat, statistical uncertainty; syst, systematic uncertainty; MeV, mega–electron volts; c, speed of light in a vacuum). This measurement is in significant tension with the standard model expectation.Funding:This work wassupported by the US Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology ofJapan; the Natural Sciences and Engineering Research Councilof Canada; the National Science Council of the Republic of China; theSwiss National Science Foundation; the Alfred P. Sloan Foundation;the Bundesministerium für Bildung und Forschung, Germany; the National Research Foundation of Korea; the Science and TechnologyFacilities Council and the Royal Society, UK; the Russian Foundationfor Basic Research; the Ministerio de Ciencia e Innovación, and Programa Consolider-Ingenio 2010, Spain; the Slovak R&D Agency;the Academy of Finland; and the Australian Research Council (ARC)

First measurement of the forward-backward asymmetry in bottom-quark pair production at high mass

Under the terms of the Creative Commons Attribution license.-- et al.We measure the particle-level forward-backward production asymmetry in bb¯ pairs with masses (mbb¯) larger than 150 GeV/c2, using events with hadronic jets and employing jet charge to distinguish b from b¯. The measurement uses 9.5 fb-1 of pp¯ collisions at a center-of-mass energy of 1.96 TeV recorded by the CDF II detector. The asymmetry as a function of mbb¯ is consistent with zero, as well as with the predictions of the standard model. The measurement disfavors a simple model including an axigluon with a mass of 200 GeV/c2, whereas a model containing a heavier 345 GeV/c2 axigluon is not excluded.This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation; the A. P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the Korean World Class University Program, the National Research Foundation of Korea; the Science and Technology Facilities Council and the Royal Society, United Kingdom; the Russian Foundation for Basic Research; the Ministerio de Ciencia e Innovación, and Programa Consolider-Ingenio 2010, Spain; the Slovak R&D Agency; the Academy of Finland; the Australian Research Council; and the EU community Marie Curie Fellowship Contract No. 302103.Peer Reviewe

Measurement of the cross section for direct-photon production in association with a heavy quark in pp̄ collisions at √s=1.96 TeV

We report on a measurement of the cross section for direct-photon production in association with a heavy quark using the full data set of √s=1.96 TeV proton-antiproton collisions corresponding to 9.1 fb -1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron. The measurements are performed as a function of the photon transverse momentum, covering a photon transverse momentum between 30 and 300 GeV, photon rapidities |yγ|20 GeV, and jet rapidities |yjet|<1.5. The results are compared with several theoretical predictions. © 2013 American Physical Society.This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation; the A. P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the Korean World Class University Program, the National Research Foundation of Korea; the Science and Technology Facilities Council and the Royal Society, UK; the Russian Foundation for Basic Research; the Ministerio de Ciencia e Innovación, and Programa Consolider-Ingenio 2010, Spain; the Slovak R&D Agency; the Academy of Finland; the Australian Research Council (ARC); and the EU community Marie Curie Fellowship Contract No. 302103.Peer Reviewe