We investigate whether transition radiation from a particle shower crossing the interface between Earth and air and induced by an Earth-skimming neutrino can explain the upward event announced ...recently by the ANITA Collaboration. While the properties of the observed signal can in principle be explained with transition radiation, a conservative upper limit on the experiment’s aperture for this kind of signal shows that the flux necessary for a successful explanation is in tension with the current best limits from the Pierre Auger Observatory, the IceCube neutrino detector, and the ANITA balloon. We also show that in this scenario, the direction of the incoming neutrino is determined precisely to within a few degrees, combining the polarization properties of the observed events with the Earth opacity to ultrahigh energy neutrinos.
Coherent radiation at radio frequencies from high-energy showers fully contained in a dense radio-transparent medium-like ice, salt, soil, or regolith-has been extensively investigated as a promising ...technique to search for ultrahigh-energy neutrinos. Additional emission in the form of transition radiation may occur when a neutrino-induced shower produced close to the Earth's surface emerges from the ground into atmospheric air. We present the first detailed evaluation of transition radiation from high-energy showers crossing the boundary between two different media. We found that transition radiation is sizable over a wide solid angle and coherent up to ~1 GHz. These properties encourage further work to evaluate the potential of a large-aperture ultrahigh-energy neutrino experiment based on the detection of transition radiation.
The origin and nature of ultrahigh-energy cosmic rays (UHECRs) is one of the most intriguing and important mysteries in astroparticle physics. The two largest observatories currently in operation, ...the Telescope Array Experiment in central Utah, USA, and the Pierre Auger Observatory in western Argentina, have been steadily observing UHECRs in both hemispheres for over a decade. We highlight the latest results from both of these experiments, and address the requirements for a next-generation UHECR observatory. The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design concept for a next-generation UHECR observa-tory, addressing the requirements for a large-area, low-cost detector suitable for measuring the properties of the highest energy cosmic rays with an unprecedented aperture. We have developed a full-scale prototype consisting of four 200 mm photomultiplier-tubes at the focus of a segmented mirror of 1.6 m in diameter. Over the last three years, we installed three such prototypes at the Black Rock Mesa site of the Telescope Array Experiment. These telescopes have been steadily taking data since installation. We report on preliminary results of the full-scale FAST prototypes, including measurements of distant ultraviolet lasers and UHECRs. Futhermore, we discuss our plan to install an additional identical FAST prototype at the Pierre Auger Observatory. Possible benefits to the Telescope Array and the Pierre Auger Observatory include a comparison of the transparency of the atmosphere above both experiments, a study of the systematic uncertainty associated with their existing fluorescence detectors, and a cross-calibration of their energy and
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Banned by the first Privileges of James I and by the Castilian Renaissance rules enforced after the Nueva Planta decrees (1707), still in the middle of the eighteenth century, overhangs and balconies ...over the public street were a problem for the city of Valencia. Indeed, the dimen-sions of these elements sometimes made impossible for transients to use the streets or they endangered people because of the poor conditions of those structures’ maintenance. This study, based on unpublished sources from the Municipal Historical Archive of Valencia, relates the development of the legal instruments of the administrative power of the city of Valencia to counteract a situation of widespread and entrenched illegality in order to relocate the public interest over the private one.
Banned by the first Privileges of James I and by the Castilian Renaissance rules enforced after the Nueva Planta decrees (1707), still in the middle of the Eighteenth Century, overhangs and balconies ...over the public street were a problem for the City of Valencia. Indeed, the dimensions of these elements sometimes made impossible for transeutents to use the streets or they endangered people because of the poor conditions of those structures’ mantaiment. This study, based on unpublished sources from the Municipal Historical Archive of Valencia, relates the development of the legal instruments of the administrative power of the City of Valencia to counteract a situation of widespread and entrenched illegality in order to relocate the public interest over the private one.
A pesar de haber sido vedados por los primeros Fueros de Jaime I y por las normas renacentistas castellana entradas en vigor después del Edicto de la Nueva Planta (1707), todavía a mediados del siglo XVIII saledizos y balcones volados sobre la calle pública representaban un problema para la capital del Turia. Efectivamente, las dimensiones de estos elementos llegaban a veces a imposibilitar el uso de las calles a los transeuntes o a ponerlos en peligro a causa de las pobres condiciones de conservación de las estructuras. Este estudio, basado en fuentes inéditas del Archivo Histórico Municipal de Valencia, relata el desarrollo de los instrumentos legales del poder administrativo de la Ciudad de Valencia para contrarrestar una situación de ilegalidad difundida y arraigada con el fin de reubicar el interés público por encima del privado.
We explore transition radiation at MHz-GHz frequencies as a possible way to detect ultrahigh-energy (UHE) particles. We have developed a general method to calculate transition radiation that extends ...the well-known Zas-Halzen-Stanev (ZHS) algorithm. We have applied it to the characterization of the frequency and angular properties of the electric field from high-energy showers crossing the boundary between two media. We discuss the potential of transition radiation for the detection of UHE particles in different situations of experimental interest.
The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a proposed low-cost, largearea, next-generation experiment for the detection of ultrahigh-energy cosmic rays (UHECRs) via the ...atmospheric fluorescence technique. Two FAST telescopes are currently installed and operating at the Black Rock Mesa site of the Telescope Array Experiment in Utah, USA. Knowledge of the properties of the atmosphere above the detector is of utmost importance for the analysis and reconstruction of the energy and trajectory of UHECRs measured with an atmospheric fluorescence telescope. The FAST experiment uses all sky camera (FASCam) and sky quality monitor (SQM) for the detection of clouds and quantification of the night-sky background light in the field-of-view of the telescopes. Measurements of a vertically-fired ultra-violet laser at a distance of 21 km from the FAST telescopes are used to infer the transparency of the atmosphere above the detector through comparison with simulations.
The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a proposed large-area, next-generation experiment for the detection of ultra-high energy cosmic rays via the atmospheric ...fluorescence technique. The telescope’s large field-of-view (30 ×30) is imaged by four 200 mm photomultiplier-tubes at the focal plane of a segmented spherical mirror of 1.6 m diameter. Two prototypes are installed and taking data at the Black Rock Mesa site of the Telescope Array experiment in central Utah, USA. We present the process used for optimization of the optical performance of this compact and low-cost telescope, which is based on a simulation of the telescope’s optical point spread function.
We present a concept for large-area, low-cost detection of ultrahigh-energy cosmic rays (UHECRs) with a Fluorescence detector Array of Single-pixel Telescopes (FAST)b, addressing the requirements for ...the next generation of UHECR experiments. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. We report on the first results of a FAST prototype installed at the Telescope Array (TA) site, consisting of a single 200 mm photomultiplier tube (PMT) at the focal plane of a 1 m2 Fresnel lens system taken from the prototype of the JEM-EUSO experiment. We also report on the status of the full-scale FAST prototype soon to be installed at the TA site, comprising a segmented spherical mirror of 1.6 m diameter and a 2 × 2 PMT camera.
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