title: First observation of PeV-energy neutrinos with IceCube.
abstract: We report on the observation of two neutrino-induced events which have an estimated deposited energy in the IceCube detector of 1.04±0.16 and 1.14±0.17 PeV, respectively, the highest neutrino energies observed so far. These events are consistent with fully contained particle showers induced by neutral-current ν(e,μ,τ) (ν(e,μ,τ)) or charged-current ν(e) (ν(e)) interactions within the IceCube detector. The events were discovered in a search for ultrahigh energy neutrinos using data corresponding to 615.9 days effective live time. The expected number of atmospheric background is 0.082±0.004(stat)(-0.057)(+0.041)(syst). The probability of observing two or more candidate events under the atmospheric background-only hypothesis is 2.9×10(-3) (2.8σ) taking into account the uncertainty on the expected number of background events. These two events could be a first indication of an astrophysical neutrino flux; the moderate significance, however, does not permit a definitive conclusion at this time.
authors.affiliation: School of Chemistry and Physics, University of Adelaide, Adelaide South Australia 5005, Australia.
authors.forename: M G
authors.initials: MG
authors.lastname: Aartsen
authors.forename: R
authors.initials: R
authors.lastname: Abbasi
authors.forename: Y
authors.initials: Y
authors.lastname: Abdou
authors.forename: M
authors.initials: M
authors.lastname: Ackermann
authors.forename: J
authors.initials: J
authors.lastname: Adams
authors.forename: J A
authors.initials: JA
authors.lastname: Aguilar
authors.forename: M
authors.initials: M
authors.lastname: Ahlers
authors.forename: D
authors.initials: D
authors.lastname: Altmann
authors.forename: J
authors.initials: J
authors.lastname: Auffenberg
authors.forename: X
authors.initials: X
authors.lastname: Bai
authors.forename: M
authors.initials: M
authors.lastname: Baker
authors.forename: S W
authors.initials: SW
authors.lastname: Barwick
authors.forename: V
authors.initials: V
authors.lastname: Baum
authors.forename: R
authors.initials: R
authors.lastname: Bay
authors.forename: J J
authors.initials: JJ
authors.lastname: Beatty
authors.forename: S
authors.initials: S
authors.lastname: Bechet
authors.forename: J
authors.initials: J
authors.lastname: Becker Tjus
authors.forename: K-H
authors.initials: KH
authors.lastname: Becker
authors.forename: M
authors.initials: M
authors.lastname: Bell
authors.forename: M L
authors.initials: ML
authors.lastname: Benabderrahmane
authors.forename: S
authors.initials: S
authors.lastname: BenZvi
authors.forename: J
authors.initials: J
authors.lastname: Berdermann
authors.forename: P
authors.initials: P
authors.lastname: Berghaus
authors.forename: D
authors.initials: D
authors.lastname: Berley
authors.forename: E
authors.initials: E
authors.lastname: Bernardini
authors.forename: A
authors.initials: A
authors.lastname: Bernhard
authors.forename: D
authors.initials: D
authors.lastname: Bertrand
authors.forename: D Z
authors.initials: DZ
authors.lastname: Besson
authors.forename: G
authors.initials: G
authors.lastname: Binder
authors.forename: D
authors.initials: D
authors.lastname: Bindig
authors.forename: M
authors.initials: M
authors.lastname: Bissok
authors.forename: E
authors.initials: E
authors.lastname: Blaufuss
authors.forename: J
authors.initials: J
authors.lastname: Blumenthal
authors.forename: D J
authors.initials: DJ
authors.lastname: Boersma
authors.forename: S
authors.initials: S
authors.lastname: Bohaichuk
authors.forename: C
authors.initials: C
authors.lastname: Bohm
authors.forename: D
authors.initials: D
authors.lastname: Bose
authors.forename: S
authors.initials: S
authors.lastname: Böser
authors.forename: O
authors.initials: O
authors.lastname: Botner
authors.forename: L
authors.initials: L
authors.lastname: Brayeur
authors.forename: H-P
authors.initials: HP
authors.lastname: Bretz
authors.forename: A M
authors.initials: AM
authors.lastname: Brown
authors.forename: R
authors.initials: R
authors.lastname: Bruijn
authors.forename: J
authors.initials: J
authors.lastname: Brunner
authors.forename: M
authors.initials: M
authors.lastname: Carson
authors.forename: J
authors.initials: J
authors.lastname: Casey
authors.forename: M
authors.initials: M
authors.lastname: Casier
authors.forename: D
authors.initials: D
authors.lastname: Chirkin
authors.forename: A
authors.initials: A
authors.lastname: Christov
authors.forename: B
authors.initials: B
authors.lastname: Christy
authors.forename: K
authors.initials: K
authors.lastname: Clark
authors.forename: F
authors.initials: F
authors.lastname: Clevermann
authors.forename: S
authors.initials: S
authors.lastname: Coenders
authors.forename: S
authors.initials: S
authors.lastname: Cohen
authors.forename: D F
authors.initials: DF
authors.lastname: Cowen
authors.forename: A H
authors.initials: AH
authors.lastname: Cruz Silva
authors.forename: M
authors.initials: M
authors.lastname: Danninger
authors.forename: J
authors.initials: J
authors.lastname: Daughhetee
authors.forename: J C
authors.initials: JC
authors.lastname: Davis
authors.forename: C
authors.initials: C
authors.lastname: De Clercq
authors.forename: S
authors.initials: S
authors.lastname: De Ridder
authors.forename: P
authors.initials: P
authors.lastname: Desiati
authors.forename: M
authors.initials: M
authors.lastname: de With
authors.forename: T
authors.initials: T
authors.lastname: DeYoung
authors.forename: J C
authors.initials: JC
authors.lastname: Díaz-Vélez
authors.forename: M
authors.initials: M
authors.lastname: Dunkman
authors.forename: R
authors.initials: R
authors.lastname: Eagan
authors.forename: B
authors.initials: B
authors.lastname: Eberhardt
authors.forename: J
authors.initials: J
authors.lastname: Eisch
authors.forename: R W
authors.initials: RW
authors.lastname: Ellsworth
authors.forename: S
authors.initials: S
authors.lastname: Euler
authors.forename: P A
authors.initials: PA
authors.lastname: Evenson
authors.forename: O
authors.initials: O
authors.lastname: Fadiran
authors.forename: A R
authors.initials: AR
authors.lastname: Fazely
authors.forename: A
authors.initials: A
authors.lastname: Fedynitch
authors.forename: J
authors.initials: J
authors.lastname: Feintzeig
authors.forename: T
authors.initials: T
authors.lastname: Feusels
authors.forename: K
authors.initials: K
authors.lastname: Filimonov
authors.forename: C
authors.initials: C
authors.lastname: Finley
authors.forename: T
authors.initials: T
authors.lastname: Fischer-Wasels
authors.forename: S
authors.initials: S
authors.lastname: Flis
authors.forename: A
authors.initials: A
authors.lastname: Franckowiak
authors.forename: R
authors.initials: R
authors.lastname: Franke
authors.forename: K
authors.initials: K
authors.lastname: Frantzen
authors.forename: T
authors.initials: T
authors.lastname: Fuchs
authors.forename: T K
authors.initials: TK
authors.lastname: Gaisser
authors.forename: J
authors.initials: J
authors.lastname: Gallagher
authors.forename: L
authors.initials: L
authors.lastname: Gerhardt
authors.forename: L
authors.initials: L
authors.lastname: Gladstone
authors.forename: T
authors.initials: T
authors.lastname: Glüsenkamp
authors.forename: A
authors.initials: A
authors.lastname: Goldschmidt
authors.forename: G
authors.initials: G
authors.lastname: Golup
authors.forename: J G
authors.initials: JG
authors.lastname: Gonzalez
authors.forename: J A
authors.initials: JA
authors.lastname: Goodman
authors.forename: D
authors.initials: D
authors.lastname: Góra
authors.forename: D
authors.initials: D
authors.lastname: Grant
authors.forename: A
authors.initials: A
authors.lastname: Groß
authors.forename: M
authors.initials: M
authors.lastname: Gurtner
authors.forename: C
authors.initials: C
authors.lastname: Ha
authors.forename: A
authors.initials: A
authors.lastname: Haj Ismail
authors.forename: P
authors.initials: P
authors.lastname: Hallen
authors.forename: A
authors.initials: A
authors.lastname: Hallgren
authors.forename: F
authors.initials: F
authors.lastname: Halzen
authors.forename: K
authors.initials: K
authors.lastname: Hanson
authors.forename: D
authors.initials: D
authors.lastname: Heereman
authors.forename: D
authors.initials: D
authors.lastname: Heinen
authors.forename: K
authors.initials: K
authors.lastname: Helbing
authors.forename: R
authors.initials: R
authors.lastname: Hellauer
authors.forename: S
authors.initials: S
authors.lastname: Hickford
authors.forename: G C
authors.initials: GC
authors.lastname: Hill
authors.forename: K D
authors.initials: KD
authors.lastname: Hoffman
authors.forename: R
authors.initials: R
authors.lastname: Hoffmann
authors.forename: A
authors.initials: A
authors.lastname: Homeier
authors.forename: K
authors.initials: K
authors.lastname: Hoshina
authors.forename: W
authors.initials: W
authors.lastname: Huelsnitz
authors.forename: P O
authors.initials: PO
authors.lastname: Hulth
authors.forename: K
authors.initials: K
authors.lastname: Hultqvist
authors.forename: S
authors.initials: S
authors.lastname: Hussain
authors.forename: A
authors.initials: A
authors.lastname: Ishihara
authors.forename: E
authors.initials: E
authors.lastname: Jacobi
authors.forename: J
authors.initials: J
authors.lastname: Jacobsen
authors.forename: K
authors.initials: K
authors.lastname: Jagielski
authors.forename: G S
authors.initials: GS
authors.lastname: Japaridze
authors.forename: K
authors.initials: K
authors.lastname: Jero
authors.forename: O
authors.initials: O
authors.lastname: Jlelati
authors.forename: B
authors.initials: B
authors.lastname: Kaminsky
authors.forename: A
authors.initials: A
authors.lastname: Kappes
authors.forename: T
authors.initials: T
authors.lastname: Karg
authors.forename: A
authors.initials: A
authors.lastname: Karle
authors.forename: J L
authors.initials: JL
authors.lastname: Kelley
authors.forename: J
authors.initials: J
authors.lastname: Kiryluk
authors.forename: F
authors.initials: F
authors.lastname: Kislat
authors.forename: J
authors.initials: J
authors.lastname: Kläs
authors.forename: S R
authors.initials: SR
authors.lastname: Klein
authors.forename: J-H
authors.initials: JH
authors.lastname: Köhne
authors.forename: G
authors.initials: G
authors.lastname: Kohnen
authors.forename: H
authors.initials: H
authors.lastname: Kolanoski
authors.forename: L
authors.initials: L
authors.lastname: Köpke
authors.forename: C
authors.initials: C
authors.lastname: Kopper
authors.forename: S
authors.initials: S
authors.lastname: Kopper
authors.forename: D J
authors.initials: DJ
authors.lastname: Koskinen
authors.forename: M
authors.initials: M
authors.lastname: Kowalski
authors.forename: M
authors.initials: M
authors.lastname: Krasberg
authors.forename: K
authors.initials: K
authors.lastname: Krings
authors.forename: G
authors.initials: G
authors.lastname: Kroll
authors.forename: J
authors.initials: J
authors.lastname: Kunnen
authors.forename: N
authors.initials: N
authors.lastname: Kurahashi
authors.forename: T
authors.initials: T
authors.lastname: Kuwabara
authors.forename: M
authors.initials: M
authors.lastname: Labare
authors.forename: H
authors.initials: H
authors.lastname: Landsman
authors.forename: M J
authors.initials: MJ
authors.lastname: Larson
authors.forename: M
authors.initials: M
authors.lastname: Lesiak-Bzdak
authors.forename: M
authors.initials: M
authors.lastname: Leuermann
authors.forename: J
authors.initials: J
authors.lastname: Leute
authors.forename: J
authors.initials: J
authors.lastname: Lünemann
authors.forename: J
authors.initials: J
authors.lastname: Madsen
authors.forename: R
authors.initials: R
authors.lastname: Maruyama
authors.forename: K
authors.initials: K
authors.lastname: Mase
authors.forename: H S
authors.initials: HS
authors.lastname: Matis
authors.forename: F
authors.initials: F
authors.lastname: McNally
authors.forename: K
authors.initials: K
authors.lastname: Meagher
authors.forename: M
authors.initials: M
authors.lastname: Merck
authors.forename: P
authors.initials: P
authors.lastname: Mészáros
authors.forename: T
authors.initials: T
authors.lastname: Meures
authors.forename: S
authors.initials: S
authors.lastname: Miarecki
authors.forename: E
authors.initials: E
authors.lastname: Middell
authors.forename: N
authors.initials: N
authors.lastname: Milke
authors.forename: J
authors.initials: J
authors.lastname: Miller
authors.forename: L
authors.initials: L
authors.lastname: Mohrmann
authors.forename: T
authors.initials: T
authors.lastname: Montaruli
authors.forename: R
authors.initials: R
authors.lastname: Morse
authors.forename: R
authors.initials: R
authors.lastname: Nahnhauer
authors.forename: U
authors.initials: U
authors.lastname: Naumann
authors.forename: H
authors.initials: H
authors.lastname: Niederhausen
authors.forename: S C
authors.initials: SC
authors.lastname: Nowicki
authors.forename: D R
authors.initials: DR
authors.lastname: Nygren
authors.forename: A
authors.initials: A
authors.lastname: Obertacke
authors.forename: S
authors.initials: S
authors.lastname: Odrowski
authors.forename: A
authors.initials: A
authors.lastname: Olivas
authors.forename: M
authors.initials: M
authors.lastname: Olivo
authors.forename: A
authors.initials: A
authors.lastname: O'Murchadha
authors.forename: L
authors.initials: L
authors.lastname: Paul
authors.forename: J A
authors.initials: JA
authors.lastname: Pepper
authors.forename: C
authors.initials: C
authors.lastname: Pérez de los Heros
authors.forename: C
authors.initials: C
authors.lastname: Pfendner
authors.forename: D
authors.initials: D
authors.lastname: Pieloth
authors.forename: E
authors.initials: E
authors.lastname: Pinat
authors.forename: N
authors.initials: N
authors.lastname: Pirk
authors.forename: J
authors.initials: J
authors.lastname: Posselt
authors.forename: P B
authors.initials: PB
authors.lastname: Price
authors.forename: G T
authors.initials: GT
authors.lastname: Przybylski
authors.forename: L
authors.initials: L
authors.lastname: Rädel
authors.forename: M
authors.initials: M
authors.lastname: Rameez
authors.forename: K
authors.initials: K
authors.lastname: Rawlins
authors.forename: P
authors.initials: P
authors.lastname: Redl
authors.forename: R
authors.initials: R
authors.lastname: Reimann
authors.forename: E
authors.initials: E
authors.lastname: Resconi
authors.forename: W
authors.initials: W
authors.lastname: Rhode
authors.forename: M
authors.initials: M
authors.lastname: Ribordy
authors.forename: M
authors.initials: M
authors.lastname: Richman
authors.forename: B
authors.initials: B
authors.lastname: Riedel
authors.forename: J P
authors.initials: JP
authors.lastname: Rodrigues
authors.forename: C
authors.initials: C
authors.lastname: Rott
authors.forename: T
authors.initials: T
authors.lastname: Ruhe
authors.forename: B
authors.initials: B
authors.lastname: Ruzybayev
authors.forename: D
authors.initials: D
authors.lastname: Ryckbosch
authors.forename: S M
authors.initials: SM
authors.lastname: Saba
authors.forename: T
authors.initials: T
authors.lastname: Salameh
authors.forename: H-G
authors.initials: HG
authors.lastname: Sander
authors.forename: M
authors.initials: M
authors.lastname: Santander
authors.forename: S
authors.initials: S
authors.lastname: Sarkar
authors.forename: K
authors.initials: K
authors.lastname: Schatto
authors.forename: M
authors.initials: M
authors.lastname: Scheel
authors.forename: F
authors.initials: F
authors.lastname: Scheriau
authors.forename: T
authors.initials: T
authors.lastname: Schmidt
authors.forename: M
authors.initials: M
authors.lastname: Schmitz
authors.forename: S
authors.initials: S
authors.lastname: Schoenen
authors.forename: S
authors.initials: S
authors.lastname: Schöneberg
authors.forename: A
authors.initials: A
authors.lastname: Schönwald
authors.forename: A
authors.initials: A
authors.lastname: Schukraft
authors.forename: L
authors.initials: L
authors.lastname: Schulte
authors.forename: O
authors.initials: O
authors.lastname: Schulz
authors.forename: D
authors.initials: D
authors.lastname: Seckel
authors.forename: Y
authors.initials: Y
authors.lastname: Sestayo
authors.forename: S
authors.initials: S
authors.lastname: Seunarine
authors.forename: C
authors.initials: C
authors.lastname: Sheremata
authors.forename: M W E
authors.initials: MW
authors.lastname: Smith
authors.forename: M
authors.initials: M
authors.lastname: Soiron
authors.forename: D
authors.initials: D
authors.lastname: Soldin
authors.forename: G M
authors.initials: GM
authors.lastname: Spiczak
authors.forename: C
authors.initials: C
authors.lastname: Spiering
authors.forename: M
authors.initials: M
authors.lastname: Stamatikos
authors.forename: T
authors.initials: T
authors.lastname: Stanev
authors.forename: A
authors.initials: A
authors.lastname: Stasik
authors.forename: T
authors.initials: T
authors.lastname: Stezelberger
authors.forename: R G
authors.initials: RG
authors.lastname: Stokstad
authors.forename: A
authors.initials: A
authors.lastname: Stößl
authors.forename: E A
authors.initials: EA
authors.lastname: Strahler
authors.forename: R
authors.initials: R
authors.lastname: Ström
authors.forename: G W
authors.initials: GW
authors.lastname: Sullivan
authors.forename: H
authors.initials: H
authors.lastname: Taavola
authors.forename: I
authors.initials: I
authors.lastname: Taboada
authors.forename: A
authors.initials: A
authors.lastname: Tamburro
authors.forename: S
authors.initials: S
authors.lastname: Ter-Antonyan
authors.forename: G
authors.initials: G
authors.lastname: Tešić
authors.forename: S
authors.initials: S
authors.lastname: Tilav
authors.forename: P A
authors.initials: PA
authors.lastname: Toale
authors.forename: S
authors.initials: S
authors.lastname: Toscano
authors.forename: M
authors.initials: M
authors.lastname: Usner
authors.forename: D
authors.initials: D
authors.lastname: van der Drift
authors.forename: N
authors.initials: N
authors.lastname: van Eijndhoven
authors.forename: A
authors.initials: A
authors.lastname: Van Overloop
authors.forename: J
authors.initials: J
authors.lastname: van Santen
authors.forename: M
authors.initials: M
authors.lastname: Vehring
authors.forename: M
authors.initials: M
authors.lastname: Voge
authors.forename: M
authors.initials: M
authors.lastname: Vraeghe
authors.forename: C
authors.initials: C
authors.lastname: Walck
authors.forename: T
authors.initials: T
authors.lastname: Waldenmaier
authors.forename: M
authors.initials: M
authors.lastname: Wallraff
authors.forename: R
authors.initials: R
authors.lastname: Wasserman
authors.forename: Ch
authors.initials: Ch
authors.lastname: Weaver
authors.forename: M
authors.initials: M
authors.lastname: Wellons
authors.forename: C
authors.initials: C
authors.lastname: Wendt
authors.forename: S
authors.initials: S
authors.lastname: Westerhoff
authors.forename: N
authors.initials: N
authors.lastname: Whitehorn
authors.forename: K
authors.initials: K
authors.lastname: Wiebe
authors.forename: C H
authors.initials: CH
authors.lastname: Wiebusch
authors.forename: D R
authors.initials: DR
authors.lastname: Williams
authors.forename: H
authors.initials: H
authors.lastname: Wissing
authors.forename: M
authors.initials: M
authors.lastname: Wolf
authors.forename: T R
authors.initials: TR
authors.lastname: Wood
authors.forename: K
authors.initials: K
authors.lastname: Woschnagg
authors.forename: C
authors.initials: C
authors.lastname: Xu
authors.forename: D L
authors.initials: DL
authors.lastname: Xu
authors.forename: X W
authors.initials: XW
authors.lastname: Xu
authors.forename: J P
authors.initials: JP
authors.lastname: Yanez
authors.forename: G
authors.initials: G
authors.lastname: Yodh
authors.forename: S
authors.initials: S
authors.lastname: Yoshida
authors.forename: P
authors.initials: P
authors.lastname: Zarzhitsky
authors.forename: J
authors.initials: J
authors.lastname: Ziemann
authors.forename: S
authors.initials: S
authors.lastname: Zierke
authors.forename: A
authors.initials: A
authors.lastname: Zilles
authors.forename: M
authors.initials: M
authors.lastname: Zoll