263 research outputs found
Plan B for particle physics: finding long lived particles at CERN
No full text
This thesis discusses the discovery potential of Intensity
Frontier experiments. As a particular examples of such experiment the SHiP
and MATHUSLA experiments where taken. The reach of these experiments was
studied for the number of specific model of the Beyond Standard Model
physics, namely neutrino Minimal Standard Model, Higgs-like scalar,
axion-like particles and light dark matter.
Theoretical Physic
Constitución y justicia constitucional en el Perú después de Fujimori
No full textEl presente artículo analiza el desarrollo y situación actual de la Justicia Constitucional en el Perú a partir de la promulgación de la Constitución de 1993. Para ello, el autor examina la situación de la Constitución en sus orígenes y años posteriores dentro del ambiente político. A continuación, se realiza un estudio sobre la reorganización de la Justicia Constitucional bajo la vigencia de la actual Constitución. Para esto, se analiza el devenir del Tribunal Constitucional, así como la reforma del proceso constitucional y las acciones constitucionales legisladas en el ordenamiento peruano. A partir de ello, el autor concluye que la Constitución ha logrado legitimarse mediante las relaciones democráticas y su reconocimiento en la práctica política. Esto habría repercutido en la impartición de la Justicia Constitucional, permitiendo al Tribunal Constitucional recuperar su rol como guardián de la Constitución This article analyzes the development and current situation of the constitutional justice in Peru from the enactment of the Constitution of 1993. To do so, the author examines the situation of the Constitution in its origins and subsequent years within the political environment. Then, he studies the reorganization of the constitutional justice under the force of the current Constitution. To this end, he discusses the evolution of the Constitutional Court, as well as the reform of the constitutional process and constitutional actions legislated in the Peruvian legal system. Based on that, the author concludes that the Constitution has managed to legitimize itself through democratic relationships and its recognition in the political practice over the years. This would have impacted on the administration of constitutional justice, allowing the Constitutional Court to recover its role as guardian of the Constitution
Constitución y justicia constitucional en el Perú después de Fujimori
No full textEl presente artículo analiza el desarrollo y situación actual de la Justicia Constitucional en el Perú a partir de la promulgación de la Constitución de 1993. Para ello, el autor examina la situación de la Constitución en sus orígenes y años posteriores dentro del ambiente político. A continuación, se realiza un estudio sobre la reorganización de la Justicia Constitucional bajo la vigencia de la actual Constitución. Para esto, se analiza el devenir del Tribunal Constitucional, así como la reforma del proceso constitucional y las acciones constitucionales legisladas en el ordenamiento peruano. A partir de ello, el autor concluye que la Constitución ha logrado legitimarse mediante las relaciones democráticas y su reconocimiento en la práctica política. Esto habría repercutido en la impartición de la Justicia Constitucional, permitiendo al Tribunal Constitucional recuperar su rol como guardián de la Constitución This article analyzes the development and current situation of the constitutional justice in Peru from the enactment of the Constitution of 1993. To do so, the author examines the situation of the Constitution in its origins and subsequent years within the political environment. Then, he studies the reorganization of the constitutional justice under the force of the current Constitution. To this end, he discusses the evolution of the Constitutional Court, as well as the reform of the constitutional process and constitutional actions legislated in the Peruvian legal system. Based on that, the author concludes that the Constitution has managed to legitimize itself through democratic relationships and its recognition in the political practice over the years. This would have impacted on the administration of constitutional justice, allowing the Constitutional Court to recover its role as guardian of the Constitution
Constitución y justicia constitucional en el Perú después de Fujimori
No full textEl presente artículo analiza el desarrollo y situación actual de la Justicia Constitucional en el Perú a partir de la promulgación de la Constitución de 1993. Para ello, el autor examina la situación de la Constitución en sus orígenes y años posteriores dentro del ambiente político. A continuación, se realiza un estudio sobre la reorganización de la Justicia Constitucional bajo la vigencia de la actual Constitución. Para esto, se analiza el devenir del Tribunal Constitucional, así como la reforma del proceso constitucional y las acciones constitucionales legisladas en el ordenamiento peruano. A partir de ello, el autor concluye que la Constitución ha logrado legitimarse mediante las relaciones democráticas y su reconocimiento en la práctica política. Esto habría repercutido en la impartición de la Justicia Constitucional, permitiendo al Tribunal Constitucional recuperar su rol como guardián de la Constitución This article analyzes the development and current situation of the constitutional justice in Peru from the enactment of the Constitution of 1993. To do so, the author examines the situation of the Constitution in its origins and subsequent years within the political environment. Then, he studies the reorganization of the constitutional justice under the force of the current Constitution. To this end, he discusses the evolution of the Constitutional Court, as well as the reform of the constitutional process and constitutional actions legislated in the Peruvian legal system. Based on that, the author concludes that the Constitution has managed to legitimize itself through democratic relationships and its recognition in the political practice over the years. This would have impacted on the administration of constitutional justice, allowing the Constitutional Court to recover its role as guardian of the Constitution
Neutrinos from the milky way
No full textA guaranteed source of neutrinos is the production in cosmic ray interactions with the interstellar matter in our Galaxy. The signal has never been detected however and only an upper limit on this flux of neutrinos has been published by the AMANDA-II detector. The ANTARES neutrino telescope, located in the Mediterranean Sea, offers a high visibility of the central region of the Milky Way, from where the highest signal is expected. ANTARES data from 2007-2012 were used to compare the flux from a region extending 39 degrees in Galactic longitude and 4.5 degrees in Galactic latitude on either side of the Galactic centre, with the flux from multiple equivalent off-source regions. No significant excess has been observed, and upper limits have been placed on the neutrino flux. The flux limits produced with ANTARES are more than a factor of 10 above the model predictions, which means that a bigger neutrino telescope is needed to constrain the models further. The future KM3NeT telescope is well suited to perform this measurement. Simulations show that by using all neutrinos flavours, KM3NeT should be able to seriously constrain the neutrino flux after about 3 years of operation.Theoretical Physic
Probing new physics in the laboratory and in space
No full textThe Standard Model (SM) of particle physics fails to explain several observed phenomena and is incomplete. In order to resolve this problem, one may extend the SM by adding new particles. However, yet they have not been observed, and currently, the scientific community tries to find a signature that manifests the existence and properties of such particles. This thesis is devoted to exploring the parameter space of Feebly Interacting new physics Particles (FIPs) in a model-independent fashion using two complementary approaches. The first one is searching for FIPs at next-generation accelerator experiments called Intensity Frontier experiments. The second one is constraining the parameter space of FIPs by considering their possible impact on the observables coming from the Early Universe - Big Bang Nucleosynthesis and Cosmic Microwave Background, which are in good agreement with the predictions of the cosmological models with SM particles. They are, therefore, very sensitive to the possible existence of FIPs in the primordial plasma. As a result of the researches constituting this thesis, novel model-independent results, as well as constraints on particular models of FIPs such as Heavy Neutral Leptons, have been obtained in both of these areas.Theoretical Physic
Optical and X-ray early follow-up of ANTARES neutrino alerts
No full textHigh-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. Even with the recent detection of extraterrestrial high-energy neutrinos by the IceCube experiment, no astrophysical neutrino source has yet been discovered. Transient sources, such as gamma-ray bursts, core-collapse supernovae, or active galactic nuclei are promising candidates. Multi-messenger programs offer a unique opportunity to detect these transient sources. By combining the information provided by the ANTARES neutrino telescope with information coming from other observatories, the probability of detecting a source is enhanced, allowing the possibility of identifying a neutrino progenitor from a single detected event.A method based on optical and X-ray follow-ups of high-energy neutrino alerts has been developed within the ANTARES collaboration. This method does not require any assumptions on the relation between neutrino and photon spectra other than time-correlation. This program, denoted as TAToO, triggers a network of robotic optical telescopes (TAROT and ROTSE) and the Swift-XRT with a delay of only a few seconds after a neutrino detection, and is therefore well-suited to search for fast transient sources. To identify an optical or X-ray counterpart to a neutrino signal, the images provided by the follow-up observations are analysed with dedicated pipelines. A total of 42 alerts with optical and 7 alerts with X-ray images taken with a maximum delay of 24 hours after the neutrino trigger have been analysed. No optical or X-ray counterparts associated to the neutrino triggers have been found, and upper limits on transient source magnitudes have been derived. The probability to reject the gamma-ray burst origin hypothesis has been computed for each alert.</p
All-flavor Search for a Diffuse Flux of Cosmic Neutrinos with Nine Years of ANTARES Data
No full textThe ANTARES detector is at present the most sensitive neutrino telescope in the northern hemisphere. The highly significant cosmic neutrino excess observed by the Antarctic IceCube detector can be studied with ANTARES, exploiting its complementing field of view, exposure, and lower energy threshold. Searches for an all-flavor diffuse neutrino signal, covering nine years of ANTARES data taking, are presented in this Letter. Upward-going events are used to reduce the atmospheric muon background. This work includes for the first time in ANTARES both track-like (mainly νμ) and shower-like (mainly νe) events in this kind of analysis. Track-like events allow for an increase of the effective volume of the detector thanks to the long path traveled by muons in rock and/or sea water. Shower-like events are well reconstructed only when the neutrino interaction vertex is close to, or inside, the instrumented volume. A mild excess of high-energy events over the expected background is observed in nine years of ANTARES data in both samples. The best fit for a single power-law cosmic neutrino spectrum, in terms of per-flavor flux at 100 TeV, is Φ1f0(100 TeV) = (1.7±1.0)×10−18 GeV−1cm−2s−1sr−1 with spectral index Γ=2.4+0.5-0.4. The null cosmic flux assumption is rejected with a significance of 1.6σ
Stacked search for time shifted high energy neutrinos from gamma ray bursts with the ANTARES neutrino telescope
No full textA search for high-energy neutrino emission correlated with gamma-ray bursts outside the electromagnetic prompt-emission time window is presented. Using a stacking approach of the time delays between reported gamma-ray burst alerts and spatially coincident muon-neutrino signatures, data from the ANTARES neutrino telescope recorded between 2007 and 2012 are analysed. One year of public data from the ICECUBE detector between 2008 and 2009 have been also investigated. The respective timing profiles are scanned for statistically significant accumulations within 40 days of the Gamma Ray Burst, as expected from Lorentz Invariance Violation effects and some astrophysical models. No significant excess over the expected accidental coincidence rate could be found in either of the two data sets. The average strength of the neutrino signal is found to be fainter than one detectable neutrino signal per hundred gamma-ray bursts in the ANTARES data at 90% confidence level
An algorithm for the reconstruction of neutrino-induced showers in the ANTARES neutrino telescope
No full textMuons created by νμ charged current (CC) interactions in the water surrounding the ANTARES neutrino telescope have been almost exclusively used so far in searches for cosmic neutrino sources. Due to their long range, highly energetic muons inducing Cherenkov radiation in the water are reconstructed with dedicated algorithms that allow for the determination of the parent neutrino direction with a median angular resolution of about 0.°4 for an E-2 neutrino spectrum. In this paper, an algorithm optimized for accurate reconstruction of energy and direction of shower events in the ANTARES detector is presented. Hadronic showers of electrically charged particles are produced by the disintegration of the nucleus both in CC and neutral current interactions of neutrinos in water. In addition, electromagnetic showers result from the CC interactions of electron neutrinos while the decay of a tau lepton produced in νт CC interactions will, in most cases, lead to either a hadronic or an electromagnetic shower. A shower can be approximated as a point source of photons. With the presented method, the shower position is reconstructed with a precision of about 1 m; the neutrino direction is reconstructed with a median angular resolution between 2° and 3° in the energy range of 1–1000 TeV. In this energy interval, the uncertainty on the reconstructed neutrino energy is about 5%–10%. The increase in the detector sensitivity due to the use of additional information from shower events in the searches for a cosmic neutrino flux is also presented
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