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Search for UHE neutrinos – in coincidence with LIGO GW150914 event – with the Pierre Auger Observatory
Lili Yang, 2016, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: The first gravitational wave transient GW150914 was observed by Advanced LIGO on September 14th, 2015 at 09:50:45 Universal Time. In addition to follow-up electromagnetic observations, the detection of neutrinos will probe deeply and more on the nature of astrophysical sources, especially in the ultra-high energy regime. Neutrinos in the EeV energy range were searched in data collected at the surface detector of the Pierre Auger Observatory within ± 500 s and 1 day after the GW150914 event. No neutrino candidates were found. Based on this non-observation, we derive the first and only one neutrino fluence upper limit at EeV energies for this event at 90% CL, and report constraints on existence of accretion disk around mergers.
Najdeno v: ključnih besedah
Ključne besede: gravitational waves, neutrinos, black hole physics
Objavljeno: 06.12.2016; Ogledov: 2097; Prenosov: 0
.pdf Polno besedilo (627,39 KB)

GRB neutrino limits from Auger
Lili Yang, prispevek na konferenci brez natisa

Opis: In this talk, I will talk about the searching for UHE neutrinos at Pierre Auger Observatory (PAO). Since no neutrino candidates is found so far. We have set the most stringent limits to point-like sources and Gamma-Ray-Bursts (GRB) of UHEν. I will also update the process of neutrino search results for PAO.
Najdeno v: ključnih besedah
Povzetek najdenega: ...will talk about the searching for UHE neutrinos at Pierre Auger Observatory (PAO). Since no...
Ključne besede: neutrinos, Pierre Auger Observatory, GRB
Objavljeno: 06.12.2016; Ogledov: 1771; Prenosov: 0
.pdf Polno besedilo (1,13 MB)
Gradivo ima več datotek! Več...

Multi-Messenger Physics With the Pierre Auger Observatory
Karl-Heinz Kampert, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, izvirni znanstveni članek

Najdeno v: ključnih besedah
Povzetek najdenega: ...Auger Observatory, ultra-high energy cosmic rays, photons, neutrinos, protons, multi-messenger physics and astrophysics...
Ključne besede: Pierre Auger Observatory, ultra-high energy cosmic rays, photons, neutrinos, protons, multi-messenger physics and astrophysics
Objavljeno: 06.05.2019; Ogledov: 687; Prenosov: 43
.pdf Polno besedilo (2,46 MB)

Ultra-high energy neutrinos searches with the Pierre Auger Observatory
Lukas Zehrer, Gašper Kukec-Mezek, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Danilo Zavrtanik, Marta Trini, 2019, objavljeni znanstveni prispevek na konferenci

Opis: In the EeV range, neutrinos are expected to be produced by ultra-high energy cosmic rays interactions with the Cosmic Microwave Background during propagation in the Universe. We report on the search for ultra-high energy neutrinos in data collected with the Surface Detector of the Pierre Auger Observatory. The searches are most efficient in the zenith angle range from 60 degrees to 95 degrees with tau neutrinos skimming in the Earth playing dominant role. The present non-detection of UHE neutrinos in the Pierre Auger Observatory excludes the most optimistic scenarios of neutrino production in terms of UHE cosmic rays chemical composition and cosmological evolution of the acceleration sites. We also report on the searches for neutrinos in coincidence with the recent Gravitational Wave events detected by LIGO/Virgo.
Najdeno v: ključnih besedah
Ključne besede: EeV neutrinos, Pierre Auger Observatory, limits
Objavljeno: 26.02.2019; Ogledov: 874; Prenosov: 0
.pdf Polno besedilo (752,61 KB)

Marta Trini, doktorska disertacija

Opis: The detection of Ultra-High-Energy (UHE) neutrinos around and above 10 18 eV (1 EeV) can be the key to answering the long-standing question of the origin of the UHE cosmic rays. The Pierre Auger Observatory is the largest experiment that can detect the extensive air showers produced when the cosmic rays and neutrinos interact in the earth’s atmosphere. In particular, with the Infilled array of the Surface Detector of the Pierre Auger Observatory we can detect sub-EeV neutrino-induced particle showers. In this thesis we demonstrate that it is possible to discriminate neutrino-induced showers from the background showers produced by the more numerous nucleonic cosmic rays. The sensitivity to neutrinos is enhanced in the inclined directions with respect to the vertical to the ground, where cosmic ray-induced showers starting in the upper layers of the atmosphere are dominated by the muonic component of the shower, while deeply- penetrating neutrino showers in contrast exhibit a large electromagnetic component. Based on this idea in this thesis we have developed a search procedure for UHE neutrinos that consists on selecting inclined events in the Infilled array of the Pierre Auger Observatory in which the signals in the water-Cherenkov stations are spread in time, characteristic of the presence of electromagnetic component in the shower. We have established a complete chain of criteria to first select the inclined events among the sample of all events triggering the Infilled array, and then identifying those that have a large electromagnetic component at ground, and hence can be considered as neutrino candidates. We have identified a single variable, the so-called area-over-peak averaged over all of the stations in each event, as a suitable observable for neutrino identification purposes. The neutrino selection was established using extensive Monte Carlo simulations of the neutrino-induced showers in the Infilled array of Auger as well as a fraction of the data assumed to be totally constituted of background nucleonic cosmic rays. Using these neutrino simulations we have also computed the exposure of the Infilled array to UHE neutrinos in the period 1 January 04 - 31 December 2017. Associated systematic uncertainties on the exposure are also described. Expecting no candidate neutrinos in the period up to 31 December 2017, and adopting a differential neutrino diffuse flux dN ν /dE ν = k E ν −2 in the energy range from 0.05 to 1 EeV, we have obtained a 90% C.L. upper limit on the all neutrino flavor, k 90 < 7.97 × 10 −8 GeV cm −2 s −1 sr −1 .
Najdeno v: ključnih besedah
Ključne besede: astroparticles, astrophysical neutrinos, cosmic rays showers, Pierre Auger Observatory, Infilled array
Objavljeno: 03.10.2019; Ogledov: 1408; Prenosov: 38
.pdf Polno besedilo (6,02 MB)

Search for Ultra-High-Energy Neutrinos with the Telescope Array Surface Detector
J. P. Lundquist, R.U. Abbasi, 2020, drugi članki ali sestavki

Opis: We present an upper limit on the flux of ultra-high-energy down-going neutrinos for E > 10^18 eV derived with the nine years of data collected by the Telescope Array surface detector (05-11-2008– 05-10-2017). The method is based on the multivariate analysis technique, so-called Boosted Decision Trees (BDT). Proton-neutrino classifier is built upon 16 observables related to both the properties of the shower front and the lateral distribution function.
Najdeno v: ključnih besedah
Ključne besede: UHECR, cosmic rays, neutrinos, pattern recognition
Objavljeno: 29.04.2020; Ogledov: 320; Prenosov: 15
.pdf Polno besedilo (1,51 MB)

Search for correlations between the arrival directions of IceCube neutrino events and ultrahigh-energy cosmic rays detected by the Pierre Auger Observatory and the Telescope Array
J. P. Lundquist, M. G. Aartsen, 2016, izvirni znanstveni članek

Opis: This paper presents the results of different searches for correlations between very high-energy neutrino candidates detected by IceCube and the highest-energy cosmic rays measured by the Pierre Auger Observatory and the Telescope Array. We first consider samples of cascade neutrino events and of high-energy neutrino-induced muon tracks, which provided evidence for a neutrino flux of astrophysical origin, and study their cross-correlation with the ultrahigh-energy cosmic ray (UHECR) samples as a function of angular separation. We also study their possible directional correlations using a likelihood method stacking the neutrino arrival directions and adopting different assumptions on the size of the UHECR magnetic deflections. Finally, we perform another likelihood analysis stacking the UHECR directions and using a sample of through-going muon tracks optimized for neutrino point-source searches with sub-degree angular resolution. No indications of correlations at discovery level are obtained for any of the searches performed. The smallest of the p-values comes from the search for correlation between UHECRs with IceCube high-energy cascades, a result that should continue to be monitored.
Najdeno v: ključnih besedah
Povzetek najdenega: ...UHECR, cosmic rays, neutrinos, multi-messenger physics, anisotropy...
Ključne besede: UHECR, cosmic rays, neutrinos, multi-messenger physics, anisotropy
Objavljeno: 30.04.2020; Ogledov: 359; Prenosov: 0
.pdf Polno besedilo (2,49 MB)

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