328 research outputs found
Dark Forces Searches at KLOE-2
Direct searches of dark matter are performed at accelerator facilities. The
existence of a new vector boson has been postulated in different scenarios
where in the most basic scheme the coupling to the SM can be achieved via a
kinetic mixing term due to the U boson. The KLOE experiment at DANE
searched for the U boson both in Dalitz decays of the meson and in
continuum events. For all of these searches an upper limit for the U boson
coupling has been established in the mass range . A summary of the different models and
searches along with results are presented.Comment: Acta Phys. Polon. B 201
KLOE/KLOE-2 results and perspectives on dark force search
During the last years several Dark Sector Models have been proposed in order to address striking astrophysical observations which fail standard interpretations. In the minimal case a new vector particle, the so called dark photon or U-boson, is introduced, with small coupling with Standard Model particles. Also, the existence of a dark Higgs boson h’ is postulated, in analogy with the Standard Model, to give mass to the U-boson through the Spontaneous Symmetry Breaking mechanism. The experiment KLOE, working on the DAΦNE e+e- collider in Frascati, searched for the existence of the U-boson in a quite complete way, investigating several different processes and final states. Tight limits on the model parameters have been set at 90%CL. Further improvements are expected in terms of sensitivity and discovery potential with the new KLOE-2 detector working on the improved DAFNE e+e- collider
Physics beyond the standard model with the J-PET detector
The Positronium (Ps) system, a bound state of an electron and a positron, is suitable for testing the predictions of quantum electrodynamics (QED), since its properties can be perturbatively calculated to high accuracy and, unlike the hydrogen system, is not affected by finite size or QCD effects at the current experimental precision level. This makes the Ps atom a good laboratory to test the Fundamental Symmetries of Physics and also search for new particles not included in the Standard Model (SM) of physics. On one hand, time reversal (T) and CP symmetry violation have never been observed in pure leptonic systems like the Ps atom, and the current experimental limits for CP and CPT violation in the decays of Ps is currently set at the level of 10, while for C violation are at the level of 10. These limits are still six and two orders of magnitude lower than the expected precision of 10 set by photon-photon interactions. Secondly, experiments searching for invisible decays of the Ps triplet state, the ortho-Positronium (o-Ps), which mainly decays to three photons, are being conducted, since they are sensitive to new physics scenarios, e.g. Mirror Matter (MM), a suitable Dark Matter candidate, proposed to restore parity (P) violation. By performing a high precision measurement of the o-Ps lifetime, the accuracy of the present QED calculations can be tested and a search for the invisible decays of the o-Ps can be performed. These studies are conducted with the novel total-body Positron-Electron Tomograph (PET) scanner at the Jagiellonian University. The J-PET is a large and high precise medical imaging tool, based on the plastic scintillators. It is a high acceptance multi-purpose detector optimized for the detection of photons from positron-electron annihilation and can be used in a broad scope of interdisciplinary investigation, e.g. medical imaging, life-time measurements, quantum entanglement studies with o-Ps, and tests of discrete symmetries
Physics beyond the standard model with the J-PET detector
The Positronium (Ps) system, a bound state of an electron and a positron, is suitable for testing the predictions of quantum electrodynamics (QED), since its properties can be perturbatively calculated to high accuracy and, unlike the hydrogen system, is not affected by finite size or QCD effects at the current experimental precision level. This makes the Ps atom a good laboratory to test the Fundamental Symmetries of Physics and also search for new particles not included in the Standard Model (SM) of physics. On one hand, time reversal (T) and CP symmetry violation have never been observed in pure leptonic systems like the Ps atom, and the current experimental limits for CP and CPT violation in the decays of Ps is currently set at the level of 10, while for C violation are at the level of 10. These limits are still six and two orders of magnitude lower than the expected precision of 10 set by photon-photon interactions. Secondly, experiments searching for invisible decays of the Ps triplet state, the ortho-Positronium (o-Ps), which mainly decays to three photons, are being conducted, since they are sensitive to new physics scenarios, e.g. Mirror Matter (MM), a suitable Dark Matter candidate, proposed to restore parity (P) violation. By performing a high precision measurement of the o-Ps lifetime, the accuracy of the present QED calculations can be tested and a search for the invisible decays of the o-Ps can be performed. These studies are conducted with the novel total-body Positron-Electron Tomograph (PET) scanner at the Jagiellonian University. The J-PET is a large and high precise medical imaging tool, based on the plastic scintillators. It is a high acceptance multi-purpose detector optimized for the detection of photons from positron-electron annihilation and can be used in a broad scope of interdisciplinary investigation, e.g. medical imaging, life-time measurements, quantum entanglement studies with o-Ps, and tests of discrete symmetries
When TEI Verse becomes linked data: using TEI tags as a model to build a linked poetry system
The Text Encoding initiative is conceived as a standard system designed to let interoperability between different projects working on analogous topics. However, interoperability is sometimes not easy to reach due to the different interpretation of tags made by each project or group. Given the variety of tags, there are several concepts that can be easily identified for many projects, such as <msIdentifier> or <incipit>, which referent is pretty clear and recognizable. There are some other tags, however, which can experience multiple interpretations, limited by the content of the attributes that modify them
Mirror matter searches with the J-PET detector
The positronium system — a bound state of an electron and a positron — is suitable for testing the predictions of quantum electrodynamics, since its properties can be perturbatively calculated to high accuracy and, unlike the hydrogen system, it is not affected by the finite size or quantum chromodynamics effects at the current level of experimental precision. Experiments searching for invisible decays of the positronium triplet state — the ortho-positronium — which mainly decays to three photons, are being conducted since they are sensitive to new physics scenarios, e.g., mirror matter, milli-charged particles, and extra space-time dimensions. The particular case of mirror matter and its search with the novel total-body positron emission tomography scanner at the Jagiellonian University is presented. This J-PET is a large, high precision medical imaging tool based on plastic scintillators
Sobre el alma: matrimonio, confesión y casuística en torno a El Burlador de Sevilla
Along its critical interpretations, El burlador de Sevilla has given ground to a series of disquisitions that have to do with the concept of «effective» and «sufficient grace» for a sinner to be forgiven. The present article widens the links between the drama and theological writings of its time, especially confessional and matrimonial casuistry, in order to approach a new theory of the donjuanesque soul, which puts it in a context of insurmountable irremissionA lo largo de su interpretación crítica El burlador de Sevilla ha dado lugar a una serie de disquisiciones concernientes a la «gracia efectiva» y «gracia suficiente» para la salvación del pecador. Este artículo amplía los vínculos entre esta comedia y la literatura teológica de su época, concretamente la casuística confesional y matrimonial, para aproximarse a una nueva teoría del alma donjuanesca que la enclava en un contexto de irremisión insalvabl
Systematics and cladistics of a new naupactini genus (Coleoptera: Curculionidae: Entiminae) from the Andes of Colombia and Ecuador
A new genus of broad-nosed weevils belonging to the tribe Naupactini (Coleoptera: Curculionidae) is described, based on six species from the Páramo-Puna subregion (Andean region) of South America. Three species are new and three have been transferred from the genus Asymmathetes (Asymmathetes nigrans, Asymmathetes rugicollis, and Asymmathetes vulcanorum). The new genus is recognized by the black, denuded, and shiny tegument, the well-developed pre-epistome, the elytral base curved backwards on middle, the reduction of the hindwings, and the widely separated procoxae, closer to the anterior than to the posterior margin of the prosternum. A cladistic analysis of the six species of the new genus plus five out-groups (Amitrus, Amphideritus, Asymmathetes, Melanocyphus, and Trichocyphus), using 49 morphological characters, resulted in a single cladogram.Fil: del Rio, Maria Guadalupe. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Malvardi, Adriana Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Lanteri, Analia Alicia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin
The KLOE-2 experiment at DAΦNE
The KLOE-2 Collaboration succesfully ended its data-taking collecting a total integrated luminosity of 5.5 fb−1 at the peak of the φ(1020) resonance at the DAΦNE collider of the Frascati LNF. New detectors have been added to the KLOE apparatus to improve the detector acceptance, the tracking capability, and also to be able to tag the scattered electrons in γγ processes. By summing the new data sample to the old one of the previous KLOE data-taking ended in 2006, a total of about 8 fb−1 has been collected, corresponding to 24 billions of φ produced. The measurement program of KLOE-2 includes precision studies on kaon and other light mesons, hadronic cross-section, and dark force searches
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