High-Energy Neutrinos Michael Kachelrie NTNU, Trondheim [] - PowerPoint PPT Presentation

High-Energy Neutrinos Michael Kachelrieß NTNU, Trondheim []

Introduction Outline of the talk 1 Introduction 2 IceCube events ◮ properties ◮ implications 3 Astrophysical sources ◮ point sources versus diffuse flux ◮ Galactic sources versus extragalactic 4 PeV dark matter 5 Summary Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 2 / 33

Introduction Outline of the talk 1 Introduction 2 IceCube events ◮ properties ◮ implications ◮ or better speculations. . . 3 Astrophysical sources ◮ point sources versus diffuse flux ◮ Galactic sources versus extragalactic 4 PeV dark matter 5 Summary Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 2 / 33

Introduction Outline of the talk 1 Introduction 2 IceCube events ◮ properties ◮ implications ◮ or better speculations. . . 3 Astrophysical sources ◮ point sources versus diffuse flux ◮ Galactic sources versus extragalactic 4 PeV dark matter 5 Summary Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 2 / 33

Introduction Outline of the talk 1 Introduction 2 IceCube events ◮ properties ◮ implications ◮ or better speculations. . . 3 Astrophysical sources ◮ point sources versus diffuse flux ◮ Galactic sources versus extragalactic 4 PeV dark matter 5 Summary Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 2 / 33

Introduction Outline of the talk 1 Introduction 2 IceCube events ◮ properties ◮ implications ◮ or better speculations. . . 3 Astrophysical sources ◮ point sources versus diffuse flux ◮ Galactic sources versus extragalactic 4 PeV dark matter 5 Summary Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 2 / 33

Introduction 1912: Victor Hess discovers cosmic rays “The results are most easily ex- plained by the assumption that ra- diation with very high penetrating power enters the atmosphere from above; the Sun can hardly be con- sidered as the source.” Hess’ and Kolhoerster’s results: 80 60 excess ionization 40 20 0 -10 1 2 3 4 5 6 7 8 9 altitude/1000m Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 3 / 33

Introduction 1912: Victor Hess discovers cosmic rays Two main questions what are they? what are their sources? Hess’ and Kolhoerster’s results: 80 60 excess ionization 40 20 0 -10 1 2 3 4 5 6 7 8 9 altitude/1000m Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 3 / 33

Introduction What do we know 100 years later? solar modulation → LHC ⇑ Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 4 / 33

Introduction What do we know 100 years later? solar modulation → Basic information: energy density ρ cr ∼ 0 . 8 eV/cm 3 non-thermal power-law spectrum, dN/dE ∝ 1 /E α nuclear composition, few e − , γ ∼ 10 18 eV isotropic flux for E < LHC ⇑ Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 4 / 33

Introduction The CR– γ – ν connection: HE neutrinos and photons are unavoidable byproducts of HECRs astrophysical models, cosmogenic flux: ◮ ratio I ν /I p determined by nuclear composition of UHECRs and source evolution ◮ ratio I ν /I γ determined by isospin Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 5 / 33

Introduction The CR– γ – ν connection: HE neutrinos and photons are unavoidable byproducts of HECRs astrophysical models, cosmogenic flux: ◮ ratio I ν /I p determined by nuclear composition of UHECRs and source evolution ◮ ratio I ν /I γ determined by isospin astrophysical models, direct flux: ◮ model dependent fluxes: ∝ target density, . . . Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 5 / 33

Introduction The CR– γ – ν connection: HE neutrinos and photons are unavoidable byproducts of HECRs astrophysical models, cosmogenic flux: ◮ ratio I ν /I p determined by nuclear composition of UHECRs and source evolution ◮ ratio I ν /I γ determined by isospin astrophysical models, direct flux: ◮ model dependent fluxes: ∝ target density, . . . top-down DM models: ◮ large fluxes with I ν ≫ I p ◮ ratio I ν /I p fixed by fragmentation Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 5 / 33

Introduction The CR– γ – ν connection: HE neutrinos and photons are unavoidable byproducts of HECRs astrophysical models, cosmogenic flux: ◮ ratio I ν /I p determined by nuclear composition of UHECRs and source evolution ◮ ratio I ν /I γ determined by isospin astrophysical models, direct flux: ◮ model dependent fluxes: ∝ target density, . . . top-down DM models: ◮ large fluxes with I ν ≫ I p ◮ ratio I ν /I p fixed by fragmentation prizes to win: ◮ astronomy above 100 TeV ◮ identification of CR sources ◮ determination galactic–extragalactic transition of CRs ◮ test/discover new particle physics Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 5 / 33

Introduction What is the bonus of HE neutrino astronomy? astronomy with VHE photons restricted to few Mpc: 22 radio 20 18 log10(E/eV) 16 photon horizon γγ → e + e − CMB 14 IR 12 10 kpc 10kpc 100kpc Mpc 10Mpc 100Mpc Gpc Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 6 / 33

Introduction What is the bonus of HE neutrino astronomy? astronomy with VHE photons restricted to few Mpc: 22 radio 20 18 log10(E/eV) 16 photon horizon γγ → e + e − CMB 14 IR ambiguity: leptonic/hadronic origin 12 10 kpc 10kpc 100kpc Mpc 10Mpc 100Mpc Gpc Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 6 / 33

Introduction HE neutrino astronomy vs UHECRs? 22 proton horizon 20 18 log10(E/eV) 16 photon horizon γγ → e + e − CMB 14 IR 12 Virgo ⇓ 10 kpc 10kpc 100kpc Mpc 10Mpc 100Mpc Gpc Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 7 / 33

Introduction HE neutrino astronomy vs UHECRs? 22 proton horizon 20 18 log10(E/eV) 16 photon horizon γγ → e + e − CMB 14 IR ◮ large statistics of UHECRs, well-suited horizon scale 12 ◮ but no conclusive evidence that qB is small enough Virgo ⇓ 10 kpc 10kpc 100kpc Mpc 10Mpc 100Mpc Gpc Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 7 / 33

Introduction What is the bonus of HE neutrino astronomy? Neutrino astronomy: small σ νN ∼ 0 . 1 ◦ − 1 ◦ large λ ν but also “large” uncertainty � δϑ � > Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 8 / 33

Introduction What is the bonus of HE neutrino astronomy? Neutrino astronomy: small σ νN ∼ 0 . 1 ◦ − 1 ◦ large λ ν but also “large” uncertainty � δϑ � > small event numbers: ∼ 1 /yr for PAO or ICECUBE 10 3 CR flux j(E) E 2 [eV cm -2 s -1 sr -1 ] 10 2 max 0.2 10 WB 1 10 -1 10 16 10 17 10 18 10 19 10 20 10 21 10 22 E [eV] ⇒ identification of steady sources challenging Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 8 / 33

Introduction What is the bonus of HE neutrino astronomy? Neutrino astronomy: small σ νN ∼ 0 . 1 ◦ − 1 ◦ large λ ν but also “large” uncertainty � δϑ � > small event numbers: ∼ 1 /yr for PAO or ICECUBE 10 3 CR flux j(E) E 2 [eV cm -2 s -1 sr -1 ] 10 2 max 0.2 10 WB 1 10 -1 10 16 10 17 10 18 10 19 10 20 10 21 10 22 E [eV] ⇒ identification of steady sources challenging correlation with AGN flares, GRBs diffuse flux detected first Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 8 / 33

Introduction IceCube [ ] Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 9 / 33

Introduction IceCube:Top View Grid North 100 m AMANDA Counting House South Pole SPASE-2 IceCube Dome Skiway Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 10 / 33

Introduction IceTop AMANDA South Pole IceCube Skiway 80 Strings 4800 PMT 1400 m 2400 m Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 10 / 33

Introduction Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 10 / 33

Icecube events Icecube: 2 events presented at Neutrino 2012 2 cascade events close to E min = 10 15 eV, bg = 0.14 Two events passed the selection criteria 2 events / 672.7 days - background (atm. � + conventional atm. � ) expectation 0.14 events preliminary p-value: 0.0094 (2.36 ��� Run118545-Event63733662 Run119316-Event36556705 August 9 th 2011 Jan 3 rd 2012 NPE 9.628x10 4 NPE 6.9928x10 4 Number of Optical Sensors 354 Number of Optical Sensors 312 CC/NC interactions in the detector MC 8 Michael Kachelrieß (NTNU Trondheim) High-Energy Neutrinos Oslo 2014 11 / 33