Search results for "HIGH ENERGY PHYSICS"
showing 10 items of 17560 documents
IceCube Search for High-Energy Neutrino Emission from TeV Pulsar Wind Nebulae
2020
Pulsar wind nebulae (PWNe) are the main gamma-ray emitters in the Galactic plane. They are diffuse nebulae that emit nonthermal radiation. Pulsar winds, relativistic magnetized outflows from the central star, shocked in the ambient medium produce a multiwavelength emission from the radio through gamma-rays. Although the leptonic scenario is able to explain most PWNe emission, a hadronic contribution cannot be excluded. A possible hadronic contribution to the high-energy gamma-ray emission inevitably leads to the production of neutrinos. Using 9.5 yr of all-sky IceCube data, we report results from a stacking analysis to search for neutrino emission from 35 PWNe that are high-energy gamma-ray…
A Search for IceCube Events in the Direction of ANITA Neutrino Candidates
2020
During the first three flights of the Antarctic Impulsive Transient Antenna (ANITA) experiment, the collaboration detected several neutrino candidates. Two of these candidate events were consistent with an ultra-high-energy up-going air shower and compatible with a tau neutrino interpretation. A third neutrino candidate event was detected in a search for Askaryan radiation in the Antarctic ice, although it is also consistent with the background expectation. The inferred emergence angle of the first two events is in tension with IceCube and ANITA limits on isotropic cosmogenic neutrino fluxes. Here, we test the hypothesis that these events are astrophysical in origin, possibly caused by a po…
Highly-resolved radiocarbon measurements on shells from Kalba, UAE, using carbonate handling system and gas ion source with MICADAS
2019
Abstract The Mini Carbon Dating System (MICADAS) represents a flexible AMS system for measuring radiocarbon samples either in the form of graphite or CO2 gas. We used the possibility to attach a carbonate handling system (CHS) to the gas ion source (GIS) to measure smaller amounts of carbonates ( 3) are used to clean the system. We tested the CHS-GIS combination on heated and unheated archaeological shells of Anadara uropigimelana from Kalba, Sharjah Emirate, United Arab Emirates (UAE). Even though the amount of carbon in the samples was small (4–22 µg C) the performance of the CO2 dating system permits the comparison of trends in the 14C data to stable isotope measurements (δ18O and δ13C)…
A laplace type problem for three lattices with non-convex cell
2016
In this paper we consider three lattices with cells represented in Fig. 1, 3 and 5 and we determine the probability that a random segment of constant length intersects a side of lattice. c ⃝2016 All rights reserved.
X-ray response of CdZnTe detectors grown by the vertical Bridgman technique: Energy, temperature and high flux effects
2016
Abstract Nowadays, CdZnTe (CZT) is one of the key materials for the development of room temperature X-ray and gamma ray detectors and great efforts have been made on both the device and the crystal growth technologies. In this work, we present the results of spectroscopic investigations on new boron oxide encapsulated vertical Bridgman (B-VB) grown CZT detectors, recently developed at IMEM-CNR Parma, Italy. Several detectors, with the same electrode layout (gold electroless contacts) and different thicknesses (1 and 2.5 mm), were realized: the cathode is a planar electrode covering the detector surface (4.1×4.1 mm2), while the anode is a central electrode (2×2 mm2) surrounded by a guard-rin…
Digital fast pulse shape and height analysis on cadmium-zinc-telluride arrays for high-flux energy-resolved X-ray imaging.
2017
Cadmium-zinc-telluride (CZT) arrays with photon-counting and energy-resolving capabilities are widely proposed for next-generation X-ray imaging systems. This work presents the performance of a 2â...mm-thick CZT pixel detector, with pixel pitches of 500 and 250â...μm, dc coupled to a fast and low-noise ASIC (PIXIE ASIC), characterized only by the preamplifier stage. A custom 16-channel digital readout electronics was used, able to digitize and process continuously the signals from each output ASIC channel. The digital system performs on-line fast pulse shape and height analysis, with a low dead-time and reasonable energy resolution at both low and high fluxes. The spectroscopic response …
Dual-polarity pulse processing and analysis for charge-loss correction in cadmium–zinc–telluride pixel detectors
2018
Charge losses at the inter-pixel gap are typical drawbacks in cadmium–zinc–telluride (CZT) pixel detectors. In this work, an original technique able to correct charge losses occurring after the application of charge-sharing addition (CSA) is presented. The method, exploiting the strong relation between the energy after CSA and the beam position at the inter-pixel gap, allows the recovery of charge losses and improvements in energy resolution. Sub-millimetre CZT pixel detectors were investigated with both uncollimated radiation sources and collimated synchrotron X-rays, at energies below and above the K-shell absorption energy of the CZT material. The detectors are DC coupled to fast and low…
Extricating New Physics Scenarios at DUNE with High Energy Beams
2017
The proposed Deep Underground Neutrino Experiment (DUNE) utilizes a wide-band on-axis tunable muon-(anti)neutrino beam with a baseline of 1300 km to search for CP violation with high precision. Given the long baseline, DUNE is also sensitive to effects due to non-standard neutrino interactions (NSI) which can interfere with the standard 3-flavor oscillation paradigm. In this Letter, we exploit the tunability of the DUNE neutrino beam over a wide-range of energies and utilize a new theoretical metric to devise an experimental strategy for separating oscillation effects due to NSI from the standard 3-flavor oscillation scenario. Using our metric, we obtain an optimal combination of beam tunes…
Femtosecond Structural Dynamics of Proteins
2016
Proteins are the workhorses of living cells, providing essential functions such as structural support, signal transduction, enzymatic catalysis, transport and storage of small ligands. Atomic-resolution structures obtained with conventional X-ray crystallography show proteins essentially as static. In reality, however, proteins move and their motion is crucial for functioning. Although the structure and dynamics of proteins are intimately related, they are not equally well understood. A very large number of protein structures have been determined, but only a few studies have been able to monitor experimentally the dynamics of proteins in real time. In the last two decades, the availability …
Interactions between saliva and flavour compounds
2016
Interactions between saliva and flavour compounds