Predictions of Ultra - High Energy Neutrino fluxes Dmitry Semikoz APC Paris

Overview: Introduction: high energy neutrinos Neutrinos from UHECR protons, diffused neutrino flux Neutrinos from astrophysical sources Conclusion

INTRODUCTION

n's in AMANDA-II We can also say a few words about localy created nus we have improvement compared to B10, better reco and energy measurement...sufficient statistics to do unfolding in statistically meaningfull way.... 1 TeV

Why UHE neutrinos can exist? Protons are attractive candidates to be accelerated in astrophysical objects up to highest energies E~1020 eV. Neutrinos can be produced by protons in P+P -> pions or P+g-> pions reactions inside of astrophysical objects or in intergalactic space. Neutrinos are produced by neutron decays: nuclei, proton-neutron conversion on CMB Neutrinos can be produced by protons or nuclei during propagation.

Pion production n p Conclusion: proton, photon and neutrino fluxes are connected in well-defined way. If we know one of them we can predict other ones:

Photons cascade down to low energies

Neutrinos from UHECR protons

The Greisen-Zatsepin-Kuzmin (GZK) effect Nucleons can produce pions on the cosmic microwave background  nucleon pair production energy loss pion production energy loss pion production rate -resonance multi-pion production sources must be in cosmological backyard within 50-100 Mpc from Earth (compare to the Universe size ~ 5000 Mpc)

HiRes: cutoff in the spectrum “GZK” Statistics 3 Expect 42.8 events Observe 15 events ~ 5 s 9 1 2 Bergman (ICRC-2005)

Auger Energy Spectrum 2007 6s -----------------------------------------

Mixed composition model: less neutrinos due to nuclei D.Allard, E.Parizot and A.Olinto, astro-ph/0512345 problem: escape of the nuclei from the source; galactic Fe?

Protons can fit UHECR data: minimal model V.Berezinsky , astro-ph/0509069 problem: composition

Photo-pion production

Parameters which define diffuse neutrino flux Proton spectrum from one source: Distribution of maximum energy of sources: Distribution of sources:

Theoretical predictions of neutrino fluxes WB bound: 1/E2 protons; distribution of sources – AGN; analytical calculation of one point near 1019 eV. MPR bound: 1/E protons; distribution of sources – AGN; numerical calculation for dependence on Emax The g-ray bound: EGRET

Parameter degeneration G.Gelmini, O.Kalashev and D.S., astro-ph/0702464

EGRET: diffuse gamma-ray flux The high energy gamma ray detector on the Compton Gamma Ray Observatory (20 MeV - ~20 GeV)

Contribution of UHECR to EGRET GLAST ------------------------------------------------------------------------------- O.Kalashev , D.S. and G.Sigl, astro-ph/0704.2463

Contribution UHECR to EGRET diffuse background for different a and m. ---------------------------------------------------------------------------------------------------

Low flux of neutrino Z.Fodor et al, hep-ph/0309171

Future detection of neutrinos from UHECR protons (2002) AGN,1/E / EUSO Old sources 1/E^2

Auger tau-neutrino limit 2007

Summary GZK neutrinos There is low bound E^2F(E) > 0.3 eV/cm^2/s/sr One need in “good” energy resolution to figure out the shape of the flux One do not need in angular resolution Search for individual sources at highest energies is hopeless

Neutrinos from astrophysical sources

TeV gamma-sources Pulsars and PWN SNRs GRBs AGNs

Problem I with TeV sources In order TeV blazars be a neutrino sources: = spg ng R>>1 = sgg ng R <<1 spg = 6x10-28cm2 while sgg = 6.65 x 10-25cm2 CONTRADICTION!!! Way out – production at different place/time or in p-p reactions.

Problem II with TeV sources Any part of TeV gamma’s can be produced by electrons One need to explain all low energy emission radio-to-X-ray in hadronic models: usually requires to introduce electrons anyway. For individual source one can spread energy in gamma-rays on larger angle –neutrino flux can be enhanced. Price – few neutrino sources as compared to gamma-rays

Neutrino production in AGN core A.Neronov & D.S., hep-ph/0208248

Example 1: blazars. Photon background in AGN core Energy scale Eg= 0.1 – 10 eV Time variability t ~ few days or R = 1016cm Model: hot thermal radiation. T=10 eV T=1 eV

Photo-pion production

Neutrino spectrum for various proton spectra and backgrounds Atm. flux 1/E E~1018eV 1/E2 AMANDA II ANTARES T=1 eV T=10 eV 1/E2

Example 2: Variable TeV emission from binary LS I +61 303 Ten points at equal phase intervals from F = 0 to F = 0.9, with MAGIC observations (where available) on the right. The periastron is at F = 0.2. MAGIC Collaboration, Science 312:1771-1773,2006 F=(2.7+-0.4+-0.8)*10-12 /cm2/s/TeV .

Electromagnetic model of binary LS I +61 303 Zdziarski et al, arXiv:0802.1174

Neutrino emission from p+p process Diego F. Torres, Francis Halzen , Astropart.Phys.27:500-508,2007. If F_nu=F_gamma 0.3-0.7 events /2.5 background /year

Other galactic sources Galactic cosmic rays (talk by A.Taylor) Milagro sources (talk by A.Kappes)

Summary neutrinos from point sources P-P reaction can give a hope to follow galactic TeV sources (example: binary systems) GLAST: May 2008! Galactic and extragalactic candidates at multi-GeV! One need in “as good as possible” angular resolution to suppress background AND to find out which source is real one. It would be nice to have good energy resolution.

Neutrinos from Galactic Supernova

Possible neutrino signals from Galactic SN in km^3 detector Prompt neutrino signal in 1-50 MeV energies. 1-10 sec after SN burst/Strong signal in each optical module / SN 1987A signal 50-200 events with E> 1TeV in 10-12 hours after burst. Shock front reached surface and became colisionless. Duration t ~ 1 hour / Waxman & Loeb 2001 SN shock interact with pre-SN wind and interstelar medium. 1000-10000 events with E>1 TeV in km^3 detector From 10 days till 1 year /Berezinsky & Ptuskin 1989

Supernova Monitor Amanda-II B10: 60% of Galaxy A-II: 95% of Galaxy IceCube: up to LMC Amanda-B10 0 5 10 sec Count rates IceCube

Pointing to Galactic SN AMANDA II can see 5-20 events with E> 1TeV. For AMANDA II angular resolution 2o of each event. Pointing to SN direction is possible with resolution ~0.5o For ANTARES pointing is up to 0.1o . Compare to SuperKamiokande 8o now and 3.5o with gadolinium. HyperKamiokande ~0.6o

Detection of Galactic SN from ‘wrong side’ by km^3 detector Atmospheric muons 5*1010/year or 300/hour/(1o)2 Signal 200 events, besides energy cut 1 TeV. Angular resolution 0.8o for each event or less then 0.1o for SN signal !!! (A.Digle, M.Kachelriess, G.Raffelt, D.S. and R.Tomas, hep-ph/0307050)

Conclusions All top-down and exotic models are not needed anymore for UHECR data. Bad news for neutrinos: no high fluxes at high energies. Secondary neutrino flux from UHECR protons can be detected by km^3 experiments. Situation will clear up in 1-2 years after input of GLAST and new results from AUGER. Neutrino flux from different kind of astrophysical sources can be detected by km^3 neutrino telescopes. However relation of neutrino fluxes to gamma-ray fluxes strongly model dependent.