scholarly journals Reflections on the anomalous ANITA events: the Antarctic subsurface as a possible explanation

2020 ◽  
Vol 61 (81) ◽  
pp. 92-98 ◽  
Author(s):  
Ian M. Shoemaker ◽  
Alexander Kusenko ◽  
Peter Kuipers Munneke ◽  
Andrew Romero-Wolf ◽  
Dustin M. Schroeder ◽  
...  

AbstractThe Antarctic Impulsive Transient Antenna (ANITA) balloon experiment was designed to detect radio signals initiated by high-energy neutrinos and cosmic ray (CR) air showers. These signals are typically discriminated by the polarization and phase inversions of the radio signal. The reflected signal from CRs suffer phase inversion compared to a direct ‘tau neutrino’ event. In this paper, we study subsurface reflection, which can occur without phase inversion, in the context of the two anomalous up-going events reported by ANITA. It is found that subsurface layers and firn density inversions may plausibly account for the events, while ice fabric layers and wind ablation crusts could also play a role. This hypothesis can be tested with radar surveying of the Antarctic region in the vicinity of the anomalous ANITA events. Future experiments should not use phase inversion as a sole criterion to discriminate between down-going and up-going events, unless the subsurface reflection properties are well understood.

2019 ◽  
Vol 216 ◽  
pp. 01009
Author(s):  
Abigail Vieregg

We summarize results from the third flight of the Antarctic Impulsive Transient Antenna (ANITA), a NASA long-duration balloon payload that searches for radio emission from the interactions of ultra-high-energy neutrinos and cosmic rays. ANITAIII was launched in December 2014 and flew for 22 days. We report the results from multipleanalyses of the data, which search for Askaryan radio emission from neutrinos interacting in the Antarctic ice as well as geomagnetic radio emission from extensive air showers (EASs) induced by cosmic rays or a tau lepton created in an in-earth tau neutrino interaction. In the most sensitive Askaryan neutrino search, we find one eventon a pre-unblinding background of 0:7−0:3+0.5. Across all searches, including a dedicated EAS search, we find a total of 28 EAS-like events. One of these events is consistent with an upward-traveling EAS, with a post-unblinding background estimate of ⪷10−2.


2019 ◽  
Vol 216 ◽  
pp. 02008 ◽  
Author(s):  
Christian Glaser

The ARIANNA detector aims to detect neutrinos with energies above 1016 eV by instrumenting 0.5 Teratons of ice with a surface array of a thousand independent radio detector stations in Antarctica. The Antarctic ice is transparent to the radio signals caused by the Askaryan effect which allows for a cost-effective instrumentation of large volumes. Several pilot stations are currently operating successfully at the Moore’s Bay site (Ross Ice Shelf) and at the South Pole. As the ARIANNA detector stations are positioned at the surface, the more abundant cosmic-ray air showers are also measured and serve as a direct way to prove the capabilities of the detector. We will present measured cosmic rays and will show how the incoming direction, polarization and electric field of the cosmicray pulse can be reconstructed from single detector stations comprising 4 upward and 4 downward facing LPDA antennas.


2019 ◽  
Vol 14 (04) ◽  
pp. P04005-P04005 ◽  
Author(s):  
M. Erdmann ◽  
F. Schlüter ◽  
R. Šmída

2019 ◽  
Vol 216 ◽  
pp. 02004 ◽  
Author(s):  
Fabrizia Canfora

The mass composition of ultra-high-energy cosmic rays plays a key role in the understanding of the origins ofthese rare particles. A composition-sensitive observable is the atmospheric depth at which the air shower reaches the maximum number of particles (Xmax). The Auger Engineering Radio Array (AERA) detects the radio emission inthe 30-80 MHz frequency band from extensive air showers with energies larger than 1017 eV. It consists of more than 150 autonomous radio stations covering an area of about 17 km2. From the distribution of signals measured by the antennas, it is possible to estimate Xmax. In this contribution three independent methods for the estimation of Xmax will be presented.


2005 ◽  
Vol 20 (29) ◽  
pp. 6869-6871 ◽  
Author(s):  
D. ARDOUIN ◽  
A. BELLETOILE ◽  
D. CHARRIER ◽  
R. DALLIER ◽  
L. DENIS ◽  
...  

We present the characteristics and performance of a demonstration experiment devoted to the observation of ultra high-energy cosmic ray extensive air showers using a radiodetection technique. In a first step, one antenna narrowed band filtered acting as trigger, with a 4σ threshold above sky background-level, was used to tag any radio transient in coincidence on the antenna array. Recently, the addition of 4 particle detectors has allowed us to observe cosmic ray events in coincidence with antennas.


2015 ◽  
Vol 66 ◽  
pp. 31-38 ◽  
Author(s):  
Jaime Alvarez-Muñiz ◽  
Washington R. Carvalho ◽  
Daniel García-Fernández ◽  
Harm Schoorlemmer ◽  
Enrique Zas
Keyword(s):  

2007 ◽  
Vol 22 (30) ◽  
pp. 2237-2246 ◽  
Author(s):  
◽  
ANDREA SILVESTRI ◽  
S. W. BARWICK ◽  
J. J. BEATTY ◽  
D. Z. BESSON ◽  
...  

The ANtarctic Impulse Transient Antenna (ANITA) is the first long-duration balloon experiment designed to search and measure the flux of Greisen–Zapsepin–Kuzmin (GZK) neutrinos. We present new limits on neutrinos fluxes of astronomical origin from data collected with the successful launch of a 2-antenna prototype instrument, called ANITA-lite, that circled the Antarctic continent for 18.4 days in January 2004. We performed a search for Ultra-High-Energy (UHE) neutrinos with energies above 3 × 1018 eV . No excess events above the background expectation were observed and a neutrino flux following E-2 spectrum for all neutrino flavors, is limited to [Formula: see text] for 1018.5 eV < Eν < 1023.5 eV at 90% confidence level. The launch of ANITA is scheduled for December 2006. Looking beyond ANITA, we describe a new idea, called ARIANNA (Antarctic Ross Iceshelf ANtenna Neutrino Array), to increase the sensitivity for GZK neutrinos by one order of magnitude better than ANITA.


2015 ◽  
Vol 754-755 ◽  
pp. 807-811
Author(s):  
A.A. Al-Rubaiee ◽  
Uda Hashim ◽  
Mohd Khairuddin Md Arshad ◽  
A. Rahim Ruslinda ◽  
R.M. Ayub ◽  
...  

The simulation of Cherenkov light Lateral distribution function (LDF) in Extensive Air Showers (EAS) initiated primary particles such as primary calcium, argon, proton iron nuclei, neutron and nitrogen have been performed using CORSIKA program for conditions and configurations of Tunka133 EAS Cherenkov array. The simulation was fulfilled at the high energy range 1014-1016eV for four different zenith angles 0o, 10o, 15oand 30o. The results of the simulated Cherenkov light LDF are compared with the measurements of Tunka133 EAS array for the same particles and energy range mentioned above. This comparison may give the good ability to reconstruct the energy spectrum and mass composition of the primary cosmic ray particles in EAS. The main feature of the given approach consists of the possibility to make a library of Cherenkov light LDF samples which could be utilized for analysis of real events which can be detected with different EAS arrays and reconstruction of the primary cosmic rays energy spectrum and mass composition of EAS particles.


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