neutrino mixing at high energy neutrino telescopes

Neutrino mixing at Neutrino mixing at high energy neutrino high energy neutrino

telescopes telescopes

Pasquale D. SerpicoPasquale D. Serpico

MPl –MunichMPl –Munich

CARE ’05 - ECFA/BENECARE ’05 - ECFA/BENE

• “Galactic -beams” and muon-damped sources

• Conclusions

• Neutrino telescopes: an overview

Overview of the TalkOverview of the Talk

P. D. Serpico, MPIfP (WHI)- Munich “Neutrino mixing @ HE P. D. Serpico, MPIfP (WHI)- Munich “Neutrino mixing @ HE telescopes” 23-25/11 /05 ECFA/BENE Week – telescopes” 23-25/11 /05 ECFA/BENE Week – CERNCERN

• Neutrino mixing at neutrino telescopes

Neutrino-telescopes: an overviewNeutrino-telescopes: an overview

High-Energy High-Energy astronomy: a new skyastronomy: a new sky


NeutrinosNeutrinos a a powerful tool for powerful tool for high energy high energy astrophysicsastrophysics

+)Directional signal (differently from CR)

+)No absorption(differently from )

+) HE guaranteed(HECR & HEobserved

Main problem-)Small

50 m

1500 m

2500 m

300

m

IceCube Collaboration

Solutions (I)Solutions (I)

huge volumes

sparse instrumentation

natural media


1 km1 km3: : Gigaton Gigaton scale!scale!

80’s: DUMAND R&D

90’s: BAIKAL, AMANDA, NESTOR

2k’s: ANTARES, NEMO R&D

<2010: ICECUBE (km3 at the

SouthPole)

……? Mediterranean km3 (Km3Net)

AMANDAICECUBE

Mediterraneankm3

BAIKAL

DUMAND

Pylos

La Seyne

Capo Passero

Baikal

South Pole


Status of Optical Cherenkov TelescopesStatus of Optical Cherenkov Telescopes

P. D. Serpico, MPIfP (WHI)- Munich “Neutrino mixing @ HE P. D. Serpico, MPIfP (WHI)- Munich “Neutrino mixing @ HE telescopes” 23-25/11 /05 ECFA/BENE Week – telescopes” 23-25/11 /05 ECFA/BENE Week –

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Flavour discrimination (I)Flavour discrimination (I)

+ N + N →→ + X (DIS) + X (DIS)11stst detection channel: detection channel: O(km) O(km) tracks tracksdirectional error: ~ 1°σ[log10(E/TeV)] : ~ 0.3coverage: 2energy range: ~ 50 GeV to 100 PeV

Cherenkov light cone(blue light)

optical sensors(PMT)


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Flavour discrimination (II)Flavour discrimination (II)22ndnd detection channel: detection channel: cascades from cascades from e e & &

CC CC + all flavors + all flavors NCNCdirectional error: ~ 10-40°σ[log10(E/TeV)] : ~ 0.1coverage: 4energy range: ~ 1 TeV to 100 PeV

ee + N + N →→ e + X (DIS) e + X (DIS)

“Glashow Resonance”

ee- →W- → anything-

e -

+ N + N →→ + X (DIS) + X (DIS)

E > few PeV

Unique to e enhanced at E ≈ 6.3

PeV

-

Gandhi et al. ‘95

Flavour discrimination (III)Flavour discrimination (III)



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3000 3000 kmkm2

Solutions (II)Solutions (II)

Upgoing shower (seen by Los Leones telescope)P. D. Serpico, MPIfP (WHI)- Munich “Neutrino mixing @ HE P. D. Serpico, MPIfP (WHI)- Munich “Neutrino mixing @ HE telescopes” 23-25/11 /05 ECFA/BENE Week – telescopes” 23-25/11 /05 ECFA/BENE Week –

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600 km radius,1.1 million km2

ANtarctic Impulsive Transient Antenna

Solutions (III)Solutions (III)


-mixing at -mixing at -telescopes-telescopes

Astrophysical fluxes come from pp→Xp→X

flavour ratios at source → e:≈⅓:⅔:0at Earth after oscillations → e:≈⅓:⅓:⅓

quite insensitive to mixing parametersdsource>> Losc → no sensitivity to msol

2 , matm2


-telescopes and -telescopes and -mixing-mixing

Standard Paradigm: Neutrino mixing Standard Paradigm: Neutrino mixing studies studies

hopeless at high energy neutrino hopeless at high energy neutrino telescopestelescopes

I shall try to argue that this is misleading!

1. Standard oscillation phenomenology “rescues” signals, allowing some interesting measurements

2. Matter effects might imply observations sensitive to m2’s, e.g. to hierarchy

Only standard oscillation

Only standard oscillation

scenarios considered!

scenarios considered!


-telescopes and -telescopes and -mixing-mixing

3. Input from -mixing very important for diagnostics of astrophysical sources

4. “Peculiar” (but not “exotic”!) neutrino sources may exist sensitive to mixing parameters (including and CP)

Event rate of O(1 yr-1 sr-1) fortwo separable and contained showers with E ≈ PeV in a km3 -telescope

H. Athar et al. APP 18 (2003) 581

Atmospheric background issofter (relevant energy losses of mesons)-suppressed (prompt ) Losc(E≈TeV-PeV) is too large

Independent confirmation of the (large) mixing in the sector via appearence


A “rescued” signal: The Galactic diffuse A “rescued” signal: The Galactic diffuse

-flux from CR hitting Galactic matter develops a large -component via oscillations.

Earth matter effectEarth matter effect with a SN at IceCubewith a SN at IceCube

Dighe et al. 06 (2003) JCAP 005

Flux vs. time at IceCube + SK (or HK)can detect Earth matter effects(normal hierarchy and sin2 13 >10-3)Exploits high statisticsfor a galactic SN


Livermore

Garching

The measurable ratio

RGR ≡ eGR

CC≈ 15[Sin2 212 +(1-0.5 Sin2 212)] (=0oand =45o)

is sensitive both to mixing angles (mainly ) AND to the production mechanism (% of pp “contamination”

≡ )(Bhattacharjee & Gupta, astro-ph/0501191)

- -


-telescopes, the Glashow resonance and -telescopes, the Glashow resonance and 1212

“Standard” astrophysical sources produce both and via

pp→X p→X

Both give flavour ratios at production e:≈⅓:⅔:0

but pmainly gives e (via +), while pp almost equally e and e

-

-

=40o

=45o

=0o

=45o

=32.5o

=15o

=0o

=45o

=9o

=0o

=45o

=32.5o

=15o

=0o


-telescopes, the Glashow resonance and -telescopes, the Glashow resonance and 1212


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““Peculiar” high energy neutrino (re)sourcesPeculiar” high energy neutrino (re)sources

In both cases, the observable ratio of tracks to e+ showers

ee

is sensitive to crucial information of the neutrino mixing matrix !!!

R=R=

1. neutrons beams from nuclear dissociations → pure e

beam

-

2. pion beams from muon damped sources → pure

beam

-

P.S. & M. Kachelrieß PRL 94, 211102 (2005) [hep-ph/0502088],P.S., work in progress

Mixing Matrix UMixing Matrix U slk ≡ Sin lk , clk≡ Cos lk

•Matter effects negligible•dsource>> Losc :Terms sensitive to m2, sign(CP) average out•Also imply equal expressions for neutrinos and antineutrinos


Neutrino Mixing - ProbabilitiesNeutrino Mixing - Probabilities

Flavor ratios at detector

Flavor ratios at source

““Galactic Galactic -beams”-beams”

Sensitivity to Sensitivity to 13 13 (and (and 2323))


=/6 =/4

Variation of order 25-50% in 0o<< 10o, depending on

(=32.5o, best case CP=)

For =45o, R is reduced even to ½ of the canonical R=0.5

Note the octant

dependence!

R Pe

Pee+Pe

e

For experimental best fit =32.5o and =45o, the flux ratio has a maximal variation of about 30%


Sensitivity to Sensitivity to CPCP

NOTE: onlysensitive to

Cos (CP)[CP-even term]

not “direct”observation

of CP-violation


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Determination of the octant of Determination of the octant of 2323

R=Pe

Pee+Pe

Model-independent statement

R<0.21 → 23 > /4

Backgrounds can only increase R!

In cosmic rays, at E ≈ O(1 EeV) a transition between High-Z nuclei

of the Galactic spectrum (acceleration and confinementrequirements are alleviated) and p-dominated Extragalactic contribution is expected. Recent CR data support this

scenario


n from nuclei dissociations in matter and fields in (a few) galactic accelerators might become visible at EeV. Favored regions: Nuclear Bulge, dense clouds (high B-field) …

Neutrinos from nuclei in the GalaxyNeutrinos from nuclei in the Galaxy

L. Anchordoqui et al. Ann. Phys. 314 (2004) 145

AGASA reported a 4% excess in UHECR around 1018 eV (1 EeV) from a couple of hot-spots in the galactic disk

Similar, indepentent hints also from SUGAR and Fly’s Eye(but negative results from preliminary analysis of Auger

data)P. D. Serpico, MPIfP (WHI)- Munich “Neutrino mixing @ HE P. D. Serpico, MPIfP (WHI)- Munich “Neutrino mixing @ HE telescopes” 23-25/11 /05 ECFA/BENE Week – telescopes” 23-25/11 /05 ECFA/BENE Week – CERNCERN

Hint: A Galactic Plane excess in EeV Cosmic Hint: A Galactic Plane excess in EeV Cosmic RaysRays

Neutrons are natural candidates to explain the signal

no GMF bending (huge for p too!)

Energy-range of the Signal ≈ boosted n-lifetime

cn ≈ 10 kpc (En / EeV)

Harari et al. JHEP 9908

The birth of Galactic neutron Astronomy? The birth of Galactic neutron Astronomy?


This energy range nicely fits the energy-window accessible to -telescopes under construction.

If neutrons come from nuclear photodissociations on Optical/UV photons, the flux is likely to extend

down to (at least) TeV region

Notice that n are undetectable as CR anisotropies below E~ 1017 eV: similar sources of lower Energy might show-up only in the e channel !!!-

The existence of galactic neutron beams would imply e fluxes up to the PeV from n-decay.

(E / En ~ Q / mn ~ 10-3→ E ~ PeV, for En ~ EeV)

-


From Neutrons to Neutrinos From Neutrons to Neutrinos

A model of galactic neutron beamsA model of galactic neutron beams

L. Anchordoqui, H. Goldberg, F. Halzen & T.J. Weiler

PLB 593 (2004) 42

Normalizing to the CR anisotropy, ~ 20 events per year from Cygnus region in IceCube (under construction at the South pole)

In a few years, IceCube should attain discovery sensitivity for n → e → !!!

Standard oscillation phenomenology implies

≈ 4 /yr tracks in 0.7o circle (Atm. background is~2.3 /yr)≈ 16 e showers/yr in 25o,

cone, due to poor resolution.(Atm. background fluctuation is~12 e/yr)


Detectability in IceCubeDetectability in IceCube

Viable models of A → n → scenarios exist, e.g.:Cygnus region: L. Anchordoqui et al. PLB 593 (2004) 42SGR A East SN remnant: Grasso and Maccione

[astro-ph/0504323]

Within the expected statistical accuracy of IceCube & at the same subleading level of other effects neglected in our estimate

From astrophysical data e.g. on the Cygnus region (e.g. UV density) and hadronic physics data (e.g. secondary populationyields in hadronic interactions)

Vnuclear dissociation ≈ 27 x Vpp hadronic interactions

In this case, likely contaminations to flux are at the O(10%) level → R ≈ + 0.02 only!


How large is the expected “pion How large is the expected “pion contamination”? contamination”?

Normalizing the anisotropy to the “n-chain” model,

n → fluxes should easily observable in IceCube,

with a detailed measurement in a decade.

High flux and R=0.5 would disprove

the dominance of A → n →

Also -rays constraints!

If the chain dominates, the flux should be much

higher, though with a flavour ratio of about 1:1:1


Is this scenario falsifiable?Is this scenario falsifiable?

muon-damped sourcesmuon-damped sources


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Sensitivity to the octant of Sensitivity to the octant of 2323

Model-independent statement

R>0.78 → 23 > /4

Backgrounds can only decrease R!

R P

1-P

e


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Why pion beams?Why pion beams?

Effective “pion beams” produced in sources where muons (but not pions) are damped sources → pure beam-

For AGN, beams @ O(106) TeV → unobservable at OCTFor GRB, beams possibily @ O(10) TeV→ optimal for

OCT!!!Flavour ratios can be used for astrophysical diagnostics

Kahsti & Waxman, PRL 95 (2005) 181101

Boosted Lifetime E

E.m. cooling time E-1 (Inv. Compton), E0 adiabatic expansion),…Their ratio increases with E, at a certain 0 the particle is stopped before decaying. The lifetime implies 00

Concluding remarksConcluding remarks


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Overview - IOverview - I

Neutrinotelescopes are optimized for astrophysical purposes, but they may have a potential for -mixing physics, too.

appearence expected to be seen within 3-4 years (IceCube completed + 1 year of running)

“Calorimentric” detection of a galactic core-collapse SN possible. Earth matter effect (and thus hierarchy/13) possibly identified at IceCube+”HK”, or +Mediterranean km3

I showed that it is conceivable or even likely that Nature might provide “-beams” (or pion beams) for free, that could be studied at -telescopes already in construction.


Overview - IIOverview - II

Going beyond the paradigm of a “canonical” flavor equipartition would repropose at neutrino telescopes the fruitful synergy between neutrino physics and astrophysical diagnostics

Measurable flavor ratios are sensitive to 13CP , and

to the octant of 23 The latter is particularly suitable

for a model-independent determination (if 23 /4)

THANK YOU!THANK YOU!

Synergy between Earth & Heaven

Atmospheric/K2KAtmospheric/K2KBest FitSin2atm=0.5, matm

2=2.2 x 10-3 eV2

3 range 0.34 < Sin2 atm < 0.66; 1.4 x 10-3matm2/eV2 < 3.3 x

10-3

Best Fit:atm= 45°

3 range: 35.7 °< sol <54.3°

Solar/KamlandSolar/KamlandBest Fit:Sin2sol=0.29, msol

2=8.1 x 10-5 eV2

3 range: 0.23 < Sin2 12 < 0.37, 7.3x 10-5 msol2/eV2 <

9.1 x 10-5

Best Fit:sol= 32.6°

3 range: 28.7 °< sol <37.5°

Global (CHOOZ+others)Global (CHOOZ+others)Best Fit: Sin213 =03 range:Sin213<0.047, 13 <12.5°

Maltoni et al., Maltoni et al., NJP 6 (2004) 122NJP 6 (2004) 122


NNeutrino mixing parameterseutrino mixing parameters

R. Gandhi, C. Quigg, M. H. Reno and I. Sarcevic, Neutrino interactions at ultrahigh energies,

Phys. Rev. D 58, 093009 (1998) [hep-ph/9807264].


((N) vs. EN) vs. E

R. Gandhi, C. Quigg, M. H. Reno and I. Sarcevic, Neutrino interactions at ultrahigh energies,

Phys. Rev. D 58, 093009 (1998) [hep-ph/9807264].


((N) vs. EN) vs. E--


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Clarification on Clarification on CPCP

CP-even

CP-odd

Jarlskog determinant

Apollonio et al. hep-ph/0210192

neutrino mixing at high energy neutrino telescopes

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