Archive for Ciencia
Analizan el plasma de quarks y gluones en el origen del Universo
http://videociencia.es//videos/36/quarks
Científicos expertos de varios países analizan desde hoy datos del experimento llevado a cabo en el laboratorio europeo de partículas CERN de recrear el plasma en el que quarks y gluones flotaban fuera de las órbitas de protones y neutrones millonésimas de segundo después del ‘Big Bang’, un fluido que podría haber dado origen al Universo.
Read more »» Analizan el plasma de quarks y gluones en el origen del Universo
Filed under: Alice experiment,Astrofisica,Atomo,Big Bang,CERN,Ciencia,Cosmologia,Cuántica,España,Fisica,Fisica de alta energia,Fisica de particulas,Fisica Nuclear,Fisica Teorica,LEP,LHC,Matematicas,Materia,Mecanica cuantica,Modelo Estandar,Science,Supersimetria,SUSY |
| Alice, Astrofisica, CERN, Ciencia, Cosmologia, España, Fisica, Fisica de particulas, Fisica Teorica, gluones, LHC, Matematicas, Mecanica cuantica, Modelo estandar, Muones, Science|No Comments
Rare Fusion Reactions Probed with Solar Neutrinos
Neutrinos coming from the sun offer a window into the inner workings of our star. Scientists have detected the neutrino signature of several different solar nuclear reactions, but other steps in the fusion process have remained elusive. Now, the Borexino Collaboration, which runs a neutrino detector that lies a kilometer below the Gran Sasso mountain in Italy, reports in Physical Review Letters that they have obtained the first evidence of a relatively rare fusion reaction in the sun, while also placing strong limits on another.
Deep in their cores, most stars get their energy by fusing hydrogen into helium. This has been verified by Earth-bound measurements of solar neutrinos, which are one of the by-products of nuclear fusion. For our sun, the dominant pathway is the proton-proton, or pp, reaction chain.
Solar models predict that other reaction pathways occur in the sun. The proton-electron-proton, or pep, reaction produces deuterium that can feed into the pp chain, but only 1 out of 400 deuterium atoms are made through pep. The signature for the pep reaction is a neutrino with a distinct energy of 1.44 mega-electron-volts, and the Borexino experiment was designed to detect neutrinos in this energy range. By carefully removing background signals from cosmic rays and other sources, such as gamma rays from the rocks surrounding the detector and from detector materials, the Borexino Collaboration (Bellini et al.) claims to have seen 3.1 pep neutrinos per day per 100 tons of detector. The team also looked for neutrinos from a separate reaction network, the carbon-nitrogen-oxygen, or CNO, cycle, but was only able to set a stringent upper limit on the flux of these neutrinos. As more data are collected, the researchers may be able to discriminate between competing models of the sun as well as disentangle the different ways neutrino flavors can mix. – Michael Schirber
Filed under: Astrofisica,CERN,Ciencia,Cuántica,Fisica,Fisica de alta energia,Fisica de particulas,Fisica Teorica,Mecanica cuantica,Neutrinos,OPERA Gran SASSO,Science,Sincrotrón |
| Astrofisica, CERN, Ciencia, Fisica, Fisica de particulas, Fisica Teorica, Neutrinos, Science|No Comments
2nd report from the LHC performance workshop
Tuesday's sessions were spent looking ahead to the possibilities for 2012. The morning started with the experiments' desiderata for the year with the key requirement being either discovery of Higgs or exclusion at the 95% confidence level down to 115 GeV. To achieve this Atlas and CMS will need an integrated luminosity in the order of 15 fb-1.
Potential improvements to performance and machine availability were then discussed with presentations on maximising the time the LHC is delivering collisions to the experiments, and the potential of the injectors to provide bunches with higher intensities and the smallest possible beam size (these fold directly into higher collision rates). Machine performance will also be improved in 2012 thanks to a number of mitigation measures taken during the Christmas stop aimed at reducing the effects of radiation on the electronics situated in the LHC tunnel.
The possibility for running at a beam energy of 4 TeV was put on the table. Discussions will continue and a final decision will be a clear outcome of the workshop. One of the big successes of 2011 was the squeeze - the reduction of the beam size at the interaction point - which was pushed in the latter part of the year. Squeezing further in 2012 might be possible in combination with the use of tighter collimator settings. This could give a peak luminosity of around 6x1033 cm-2s-1 to be compared with a maximum of 3.6x1033 cm-2s-1 in 2011.
With a bunch spacing of 50 ns, a total of 1380 bunches (as in 2011), 15 fb-1 seems to be in reach if the tighter collimator settings prove to be operationally robust and the impressive performance of the LHC's many hardware systems continues.
Filed under: CERN,Ciencia,Cosmologia,Fisica,Fisica de alta energia,Fisica de Materiales,Fisica de particulas,LHC,Matematicas,Materia,Mecanica cuantica,Science,Sincrotrón |
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Los últimos análisis de ATLAS y CMS sobre la búsqueda del Higgs en el LHC, listos para su publicación
Los análisis sobre la búsqueda del bosón de Higgs predicho por el Modelo Estándar de Física de Partículas, presentados por los experimentos ATLAS y CMS del Gran Colisionador de Hadrones (LHC) en el Centro Europeo para la Investigación Nuclear (CERN) el pasado mes de diciembre, han sido enviados hoy para su publicación a la revista Physics Letters B. Tras realizar más análisis, la significación estadística de los resultados permanece cercana a la presentada en aquel seminario, remarcando la conclusión de que el bosón de Higgs del Modelo Estándar, si existe, es probable que tenga una masa entre los 116 y 131 GeV (gigaelectronvoltios), según el experimento ATLAS, y los 115-127 GeV, según CMS. Indicios “prometedores” han sido observados por ambos experimentos entre los 124 y 126 GeV, aunque no son lo suficientemente robustos como para ser considerados un descubrimiento.
“Nuestros análisis sobre el bosón de Higgs del Modelo Estándar con los datos obtenidos hasta ahora por el LHC nos dejan en una posición muy estimulante de cara a 2012”, dijo el director de Investigación del CERN, Sergio Bertolucci. “Con los datos obtenidos este año, seremos capaces de confirmar o descartar definitivamente el bosón de Higgs predicho por el Modelo Estándar”.
Filed under: Astrofisica,Atlas experiment,Atomo,Big Bang,CERN,Ciencia,CMS experiment,Cosmologia,CPAN,CSIC,Cuántica,España,Estados Unidos,Europa,Fisica,Fisica de alta energia,Fisica de particulas,Fisica Nuclear,Fisica Teorica,Higgs,LEP,LHC,Matematicas,Materia,Mecanica cuantica,Modelo Estandar,Science,Sincrotrón,Supersimetria,SUSY |
| Astrofisica, Atlas, CERN, Ciencia, CMS, Cosmologia, cpan, CSIC, España, Fisica, Fisica de particulas, Fisica Teorica, LHC, Matematicas, Mecanica cuantica, Science|No Comments
1st report from the LHC performance workshop
Yesterday, 6 February, the LHC Performance workshop 2012 kicked off in a very chilly Chamonix (-12 degrees C in town at midday, nearer -30 on the top of Les Grand Montets). The first day was devoted to a critical review of 2011.
2011 was a very good year for the machine and its experiments but the first day of the Workshop focused on examining the performance and identifying possible improvements to critical systems such as beam instrumentation and machine protection. The high-intensity beams that LHC managed to collide last year have sparked a number of issues around the ring including beam-induced heating of some hardware, and problematic vacuum spikes. Present understanding of these problems was presented and possible solutions discussed.
The immediate aim is to maximize the performance of the 2012 run with one eye on the more distant future.
Filed under: CERN,Ciencia,Cosmologia,Fisica,Fisica de alta energia,Fisica de Materiales,Fisica de particulas,LHC,Matematicas,Materia,Mecanica cuantica,Science,Sincrotrón |
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Encuentro de transferencia tecnológica en detectores sensibles de posición de estado sólido
La red europea AIDA (Advanced European Infrastructures for Detectors at Accelerators), con el apoyo de la red HEPTech, organiza en DESY (Hamburgo) un evento de transferencia tecnológica en detectores sensibles de posición de estado sólido, donde se tratarán sus aplicaciones en otros campos como Medicina, Ingeniería o Ciencias de la Vida. La Oficina de Transferencia Tecnológica (KTO) del Centro Nacional de Física de Partículas, Astropartículas y Nuclear (CPAN) participa en el encuentro, que se desarrolla el 26 y el 27 de marzo de 2012.
Los detectores sensibles de posición de estado sólido se utilizan cada vez más en numerosos campos, debido a su versatilidad y otras características ventajosas. En física de partículas se encuentran entre las tecnologías más adecuadas desarrolladas hasta el momento para el seguimiento de las trayectorias de las partículas.
Read more »» Encuentro de transferencia tecnológica en detectores sensibles de posición de estado sólido
Filed under: Astrofisica,CERN,Ciclotrón,Ciencia,CLIC,Cosmologia,CPAN,CSIC,Cuántica,España,Estados Unidos,Europa,FAIR,Fermilab,Fisica,Fisica de alta energia,Fisica de particulas,Fisica Nuclear,Fisica Teorica,ILC,LEP,LHC,Matematicas,Materia,Mecanica cuantica,Science,Sincrociclotrón,Sincrotrón,SLAC,SuperB |
| Astrofisica, CERN, Ciencia, CLIC, Cosmologia, cpan, CSIC, FAIR, Fermilab, Fisica, Fisica de particulas, Fisica Teorica, ILC, LHC, Matematicas, Mecanica cuantica, Science, SuperB|1 Comment
La ‘Posidonia oceanica’ es la especie más longeva de la biosfera
Un equipo de investigadores del Consejo Superior de Investigaciones Científicas (CSIC) ha hallado en Formentera un clon de Posidonia oceanica, una especie marina amenazada y endémica del Mediterráneo, con 100.000 años de edad. Los resultados, publicados en el último número de la revista PLoS ONE, convierten a esta especie en la más longeva de la biosfera.
Pradera de ‘Posidonia oceanica’ de Formentera, donde se ha encontrado el ejemplar más longevo./ MANU SANFELIX.
La clave se encuentra en el crecimiento clonal, un proceso que Posidonia comparte con el resto de las angiospermas (plantas superiores con flor) marinas. Está basado en la continua división de sus meristemos (regiones donde se producen nuevas células) y rizomas, tallos que crecen a un ritmo extremadamente lento, aproximadamente un centímetro al año, y conectan las nuevas plantas que se van creando.
Read more »» La ‘Posidonia oceanica’ es la especie más longeva de la biosfera
Filed under: Biodiversidad,Biologia,Calentamiento Global,Cambio climatico,Ciencia,CSIC,Documentales,Ecologia,España,Medio ambiente,Science |
| Biodiversidad, Biologia, Ciencia, CSIC, Ecologia, España, Posidonia, Science|No Comments
NASA’s IBEX Spacecraft Reveals New Observations of Interstellar Matter
Artículo publicado el 31 de enero de 2012 en NASA
El Explorador del Límite Interestelar (IBEX) de la NASA ha captado la mejor y más completa visión de lo que hay más allá de nuestro Sistema Solar. Las nuevas medidas nos dan pistas sobre cómo y dónde se formó el Sistema Solar, las fuerzas que físicamente le dan forma, y la historia de otras estrellas de la Vía Láctea.
La nave, que orbita alrededor de la Tierra, observó cuatro tipos distintos de átomos incluyendo el hidrógeno, oxígeno, neón y helio. Estos átomos interestelares son subproductos de estrellas más antiguas, las cuales se extienden por toda la galaxia y llenan el vasto espacio entre las estrellas. IBEX determinó la distribución de estos elementos fuera del Sistema Solar, que son un flujo de partículas cargadas y neutras que viajan a través de la galaxia, o lo que se conoce como viento interestelar.
IBEX 1/31/2012 Update – Scientists Discuss Space Matter
During a press briefing, Scientists discussed new findings by NASA’s Interstellar Boundary Explorer, or IBEX spacecraft which are helping fill holes in our knowledge about the matter found between the stars in our Milky Way galaxy. IBEX, whose primary focus has been the interaction between our solar system and what lies beyond, has directly sampled multiple heavy elements within this interstellar medium, the same materials of which stars, planets — even people, are made.
The much awaited IBEX update. Not much here IMHO. Most interesting is they didn’t add any known Planets closer than Alpha Centauri. However, they only listed STARS with known Planets, I’m not sure if that would include single Planets or not. Still waiting on the Full WISE release…
It appears the audio is not synched in the 360p version, the other versions are fine.
“During a press briefing, Scientists discussed new findings by NASA’s Interstellar Boundary Explorer, or IBEX spacecraft which are helping fill holes in our knowledge about the matter found between the stars in our Milky Way galaxy. IBEX, whose primary focus has been the interaction between our solar system and what lies beyond, has directly sampled multiple heavy elements within this interstellar medium, the same materials of which stars, planets — even people, are made.”
From Dave McComas, IBEX Principal Investigator:
http://ibex.swri.edu/
IBEX: Glimpses of the Interstellar Material Beyond our Solar System: http://www.nasa.gov/mission_pages/ibex/news/interstellar-difference.html
Voyager: http://www.nasa.gov/mission_pages/voyager/index.html
IBEX Conference Multimedia Downloads:http://svs.gsfc.nasa.gov/vis/a010000/a010900/a010906/
NPP VIIRS Eastern Hemisphere Image – Behind the Scenes 02.02.12: http://www.nasa.gov/topics/earth/features/viirs-globe-east.html
Read more »» NASA’s IBEX Spacecraft Reveals New Observations of Interstellar Matter
Filed under: Astrofisica,Astronomia,Ciencia,Cosmologia,Fisica,Galaxias,Materia,Nasa,Science,Universo |
| Astrofisica, Astronomia, Ciencia, Cosmologia, Fisica, Gañaxia, Interstellar Matter, Nasa, NASA IBEX, Science, Universo, Via Lactea|No Comments
Procedure for obtaining visas for Switzerland and France Signature rights
In accordance with the Status Agreements with CERN, Switzerland and France facilitate the entry of members of the Organization’s personnel on to their territories. Where relevant, detailed procedures for obtaining visas apply.
Within the framework of those procedures, only the following individuals are authorised to initiate the note verbale procedure as well as to sign the Official Invitation Letters and the Conventions d’accueil.
- Kirsti ASPOLA (PH – CMO)
- Oliver BRÜNING (BE – ABP)
- Michelle CONNOR (PH – AGS)
- Patrick FASSNACHT (PH-ADO)
- David FOSTER (IT – DI)
- Nathalie GRÜB (PH – AGS)
- Tjitske KEHRER (DG-DI)
- Tadeusz KURTYKA (DG – PRJ)
- Markus NORDBERG (PH – ADO)
- Cécile NOELS (DG – PRJ)
- Maria QUINTAS (HR – SPS)
- Kate RICHARDSON (PH-AGS)
- Jeanne ROSTANT (PH – AGS)
- José SALICIO-DIEZ (PH – AGS)
- Ulla TIHINEN (PH – AGS)
- Emmanuel TSESMELIS (DG)
- Rüdiger VOSS (PH – ADE
The French and Swiss Authorities will reject any request signed by a person who is not on this list.
We would like to remind you that in accordance with the memorandum of 7 December 2000 issued by the Director of the Administration, (ref. DG/DA/00-119), “the Organization shall not request any legitimisation document (or residence permit) or visa from the Host States for persons registered as EXTERNAL" (people who do not hold a contract of employment, association or apprenticeship with CERN).
We would also like to remind you that those coming to CERN should find out in good time about the conditions of entry to Switzerland and France applying to them and ensure that they obtain the requisite visas, where applicable, in the country in which they are habitually resident.
Useful information can be obtained from the Swiss and French diplomatic representations abroad, as well as from the following Web pages :
• http://www.bfm.admin.ch/content/bfm/en/home/dokumentation/rechtsgrundlagen/weisungen_und_kreisschreiben/visa/liste1_staatsangehoerigkeit.html (Swiss Federal Office for Immigration) ;
• http://www.diplomatie.gouv.fr/en/france_159/coming-to-france_2045/getting-visa_2046/general-information-for-foreign-nationals-with-ordinary-passeports_1559.html (French Ministry of Foreign and European Affairs).
The Authorities of the Host States have informed the Organization on a number of occasions that they insist upon scrupulous compliance with visa legislation.
Relations with the Host States Service
http://www.cern.ch/relations/
relations.secretariat@cern.ch
Filed under: CERN,Ciencia,Cosmologia,Fisica,Fisica de alta energia,Fisica de Materiales,Fisica de particulas,LHC,Matematicas,Materia,Mecanica cuantica,Science,Sincrotrón |
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LHC Report: Restart preparations continue
Maintenance and consolidation work has been progressing well in both the machine and the experiments in preparation for the March restart.
A sample material is attached to the LHC (the white bag taped to the green line), to measure the radiation doses.
Additional work was required around Point 5 due to the discovery and repair of a problem with the RF fingers at the connection of two beam vacuum chambers in CMS. The repair has been completed successfully and the sector is now under vacuum. In order to avoid rushing the delicate final operations required for closing the detector, the restart of the machine has been postponed by one week, from 7 March to 14 March.
In the machine, the first cool-down to 1.9 K has started in several sectors ,and the cool-down of the whole machine is still planned to be finished by 21 February. The time window between 22 February and 14 March will be dedicated to powering and cryogenic tests.
Since 12 December, the Radiation Protection (RP) group has been deeply involved in the work in the accelerator complex to ensure the protection of people against ionising radiation. For this purpose, the RP group determines the hazards associated with prompt and residual radiation exposure and performs the radiological area classification, materials classification and risk analysis of work places.
“The radiation dose to carbon-based materials (cable and magnet coil insulation) used in the accelerator complex is recorded. Since last year, the LHC has been equipped with 550 radio-photoluminescent (RPL) dosimeters,” explains Julia Trummer from the Radiation Protection group. “RPL dosimeters are tiny glass cylinders of 6mm in length and 1mm in diameter. Radiation creates luminescence and colour centres in the glass. The luminescence centres are excited by a UV source and the intensity of the emitted light is related to the radiation dose. The doses that can be measured range from a few Gy up to MGy.”
“In order to prepare for future interventions – especially those during the next long shutdown – material samples are being placed in selected areas,” adds Cristina Adorisio, also an RP group member. “These samples contain materials used in the connections between the magnets. An activation measurement of these samples will help to estimate dose values to workers.”
Filed under: CERN,Ciencia,Cosmologia,Fisica,Fisica de alta energia,Fisica de Materiales,Fisica de particulas,LHC,Matematicas,Materia,Mecanica cuantica,Science,Sincrotrón |
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