Search results for " Experiment"
showing 10 items of 13414 documents
Possibilities for Underground Physics in the Pyh\"asalmi mine
2018
The Pyh\"asalmi mine is uniquely suited to host new generation of large-scale underground experiments. It was chosen both by the LAGUNA-LBNO and by the LENA Collaboration as the preferred site for a giant neutrino observatory. Regrettably, none of these projects got funded. The termination of the underground excavations in the fall of 2019 marks an important milestone. To maintain the infrastructure in good condition a new sponsor must be found: either a large-scale scientific project or new commercial operation. The considered alternatives for the commercial used of the mine include a pumped-storage hydroelectricity plant and a high-security underground data-storage centre. Without a new s…
Search for new physics in single-top-quark production with the ATLAS detector at the LHC
2018
Esta tesis presenta dos análisis dedicados a la búsqueda de nueva física en eventos de producción de quarks top únicos con datos recopilados por el detector ATLAS en el LHC. A pesar de su gran éxito, se cree que debe haber una teoría más general que subyace al Modelo Estándar de física de partículas que arroge luz a preguntas sin respuesta, como la asimetría de materia-antimateria del universo o la existencia de la Materia Oscura. Esta tesis cubre dos enfoques diferentes para abordar los dos temas anteriores. El objetivo del primer análisis es explorar la estructura del vértice Wtb a través de la medición de asimetrías angulares relacionadas con los observables de polarización del bosón W q…
Production of light nuclei and anti-nuclei in pp and Pb-Pb collisions at energies available at the CERN Large Hadron Collider
2016
The production of (anti-)deuteron and (anti-) 3 He nuclei in Pb-Pb collisions at √sNN = 2.76 TeV has been studied using the ALICE detector at the LHC. The spectra exhibit a significant hardening with increasing centrality. Combined blast-wave fits of several particles support the interpretation that this behavior is caused by an increase of radial flow. The integrated particle yields are discussed in the context of coalescence and thermal-statistical model expectations. The particle ratios, 3 He /d and 3 He /p, in Pb-Pb collisions are found to be in agreement with a common chemical freeze-out temperature of Tchem ≈ 156 MeV. These ratios do not vary with centrality which is in agreement with…
L'impact de l'information sur le résultat d'une vente aux enchères expérimentale de vin
2005
This paper reports the results of an experimental wine auction. Participants of the experiment were randomly assigned to three rooms. In each room four wines had to be evaluated, but the level of information to which participants had access differed across rooms. After the evaluations, the wines were sold sequentially, by four separate Vickrey auctions with secret reservation prices. We fi nd that certain socio-economic characteristics such as gender, income and consumption habits, have a signifi cant impact on the willingness to pay for wine, while others such as age and nationality, do not. We also fi nd that once individuals have read the label characteristics and extracts from wine guid…
El “giro morfológico”: la forma, condición del sentido
2006
This paper starts from the philosophical contradiction that we can call 'apory of logical fundament'. Logic appears, on the one side, as having the metaphysical pretensions of universality and wholeness and, on the other side, as having local efficiency in computers' concrete world. Several alternatives have tried to go over this apory, from alogical philosophies to logic amplifying attempts. René Thom's ontology changes the terms of the question and, instead of looking for the fundament in logic, he does so in topology. His slogan is: 'We have to found, not geometry in logic, but logic in geometry'. The fundamental ontological implication of this morphologic change is to find the sense con…
Measurement of top-quark polarisation observables and a search for dark matter in single-top-quark production with the ATLAS detector at the LHC
2022
Esta tesis presenta dos análisis diferentes basados en los datos resultantes de colisiones protón-protón a una energía en el centro de masas de 13 TeV recolectados con el detector ATLAS del LHC, correspondientes a una luminosidad integrada de 139 fb$^{-1}$. El primer análisis presenta una medida de secciones eficaces diferenciales normalizadas del canal de producción de quarks top en solitario $t$-channel, donde el quark top se desintegra leptónicamente, como función de los tres ángulos de polarización del leptón para eventos con quarks top y quarks antitop tanto separadamente como de forma inclusiva. Estos observables son particularmente sensibles a efectos de nueva física en el vértice $t…
Azimuthally Differential Pion Femtoscopy in Pb-Pb Collisions at √sNN = 2.76 TeV
2017
We present the first azimuthally differential measurements of the pion source size relative to the second harmonic event plane in Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of √ s N N = 2.76 TeV . The measurements have been performed in the centrality range 0%–50% and for pion pair transverse momenta 0.2 < k T < 0.7 GeV / c . We find that the R side and R out radii, which characterize the pion source size in the directions perpendicular and parallel to the pion transverse momentum, oscillate out of phase, similar to what was observed at the Relativistic Heavy Ion Collider. The final-state source eccentricity, estimated via R side oscillations, is found to b…
Study of production and cold nuclear matter effects in pPb collisions at=5 TeV
2014
Production of mesons in proton-lead collisions at a nucleon-nucleon centre-of-mass energy = 5 TeV is studied with the LHCb detector. The analysis is based on a data sample corresponding to an integrated luminosity of 1.6 nb(-1). The mesons of transverse momenta up to 15 GeV/c are reconstructed in the dimuon decay mode. The rapidity coverage in the centre-of-mass system is 1.5 < y < 4.0 (forward region) and -5.0 < y < -2.5 (backward region). The forward-backward production ratio and the nuclear modification factor for (1S) mesons are determined. The data are compatible with the predictions for a suppression of (1S) production with respect to proton-proton collisions in the forward region, an…
Measurement of D*(+/-) meson production in jets from pp collisions at root s=7 TeV with the ATLAS detector
2012
This paper reports a measurement of D*(+/-) meson production in jets from proton- proton collisions at a center- of- mass energy of root s = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb(-1) for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range vertical bar eta vertical bar D-0 pi(+), D-0 -> K-pi(+), and its charge conjugate. The production rate is found to be N(D*(+/-))/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*(+/-) mesons that carry a fraction z of the jet momentum in the range 0.3< z< 1. Monte Carlo predictions fail to describe the dat…
Der Zerfall des 2,4-sec100Nb
1972
The nuclide100Nb was produced by irradiation of enriched100Mo targets with 14 MeV-neutrons, and its decay properties were investigated employing scintillation and semiconductor spectrometers and coincidence techniques. A half-life of 2.4±0.3 sec and aQ β-value of 5.8±0.2 MeV were found. From 27 gamma-rays, 20 transitions, representing 95% of the observed gamma-ray intensity, could be placed in a decay scheme comprising 10 excited states of100Mo.