Transcript Neutrino Astrophysics - Vanderbilt University

High-Energy Neutrino Astrophysics
Tom Weiler
Vanderbilt University
Neutrinos and the Early Universe”,
Trento ECT* Workshop,
October 4-8 2004
ECT*, October 7 2004
Tom Weiler, Vanderbilt University
Cosmic Photo- Proto-Spectra
SN87a sun
Neutrino
Incognito
hadron wall?
no wall a’tall
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Tom Weiler, Vanderbilt University
1991
Fly’s Eye reports 3x1020 eV, with proton-like profile;
Akeno/AGASA Xpt begins
mid-90sDUMAND taken off life-support; Baikal continues
90s
SuperK neutrinos from the sun (directional astro)
1996
AGASA reports event clustering within 2.50 ang. res’n
and: F(E  1020 eV) ~ 1/km2/century,
with shower diameter ~ 5km, N(e) ~ 1011
2000
20 events at and above 1020 eV
2001
HiRes withdraws 7 events; AGASA adds 6 (from z > 45o);
And the controversy has begun!
Importantly, Auger gets first “light”
2002
AMANDA pushes to 1014 eV thru-Earth neutrinos
2005
Auger Observatory data expected
2008
Extreme Universe Space Observatory (EUSO) ?
ECT*, October 7 2004
Tom Weiler, Vanderbilt University
CR Spectrum above a TeV
from Tom Gaisser
VLHC
(100 TeV)2
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Tom Weiler, Vanderbilt University
Highest Energy Event
The CR record energy is 3x1020 eV (0.3 ZeV).
Found by Fly’s Eye a decade ago (they got lucky!).
This is truly a macroscopic energy:
3x1020 eV = 50 Joules
equivalent to a Roger Clemens fastball,
a Tiger Woods tee shot,
a Pete Sampras tennis serve,
Or a speeding bullet.
(Also to 12 Calories, which heats a gram of water by 12oC)
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Tom Weiler, Vanderbilt University
3 x1020 eV = macroscopic 50 Joules
Clemens does this with 1027 nucleons;
Nature does this with one nucleon,
1027 times more efficient !
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Tom Weiler, Vanderbilt University
Fly’s Eye 3x1020 eV event (1992)
This longitudinal profile is
consistent with a primary
proton, but not with a
primary photon;
Disfavors “local” top-down
sources such as massive
Particle DK, topo-defects,
Z-bursts, etc.
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100 billion e+e- pairs
at xmax ~ 800 g/cm2
Tom Weiler, Vanderbilt University
EE Neutrinos are young
Liberated at T=Mev, t= 1 sec
Depends on energy (Lorentz boost)
Consider a 1020 eV neutrino.
Lorentz factor = 1021 for mn = 0.1 eV.
Age of Uni is 1018 sec,
But age of n is 1018/1021 sec = 1 millisecond !
And it doesn’t even see the stream of radiation
rushing past it – untouched !
ECT*, October 7 2004
Tom Weiler, Vanderbilt University
Size matters
EUSO ~ 300 x AGASA ~ 10 x Auger
EUSO (Instantaneous) ~3000 x AGASA ~ 100 x Auger
Exposure
10000
Exposure
1000
AGASA
HiRes
Auger
EUSO
100
10
1
90 92 94 96 98 00 02 04 06 08 10 12 14
19 19 19 19 19 20 20 20 20 20 20 20 20
Year
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Tom Weiler, Vanderbilt University
Extreme Universe Space Observatory
2009
EUSO onboard the ISS (Or Not!)
2012
Hundredth anniversary of Hess
– EUSO finishes three-year data-taking
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Tom Weiler, Vanderbilt University
“clear moonless nights”
Or New York State
power blackout
Blackout_14aug03.jpeg
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Tom Weiler, Vanderbilt University
Orbiting Wide-angle Lens (OWL)
3000 events/year
above 1020eV
and UHE Neutrinos!
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Tom Weiler, Vanderbilt University
n HAS event rate is small
e.g. FCR at 1020 eV implies 10-2 events/yr;
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Tom Weiler, Vanderbilt University
AGASA Spectrum: EeV to ZeV
AGASA, July 2002
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Tom Weiler, Vanderbilt University
Greisen-Zatsepin-Kuzmin and
the Cosmic-Ray Wall
Photo-pion production off CMB
p+cmb  p/n+
-resonance
multi-pions
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Tom Weiler, Vanderbilt University
HiRes vs. AGASA UHE spectrum
FlysEye event goes here
discovery
opportunity
GZK recovery ?
Z-burst uncovery ?
EUSO reach x 103 better
ECT*, October 7 2004
Tom Weiler, Vanderbilt University
AGASA hot-spots -- Data
red: E > 4 1019 eV
green: E > 1020 eV
Cluster Component
~ E -1.8±0.5
Neutrinos will point better
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Tom Weiler, Vanderbilt University
AGASA hot-spots -- numbers
Within 2.5 degree circles,
AGASA identifies six doublet, one triplet,
Out of 57 events;
Opening the angle to just 2.6 degrees,
AGASA identifies seven doublets, two triplets;
Source number ~ N12/2N2 ~ 270 to 50%,
weighting with GZK suppression,
~ 10-5 /Mpc3 for source density
Haverah Park contributes two more paired events
in AGASA directions.
NOT corroborated by HiRes.
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Tom Weiler, Vanderbilt University
Berezinsky et al Xgal proton flux
Mass-composition data (HiRes 2002)
Theory threshold for p2.7Kpe+eand data (knee) are at 1017.6 eV.
Xgal proton dominance
begins at 1018 eV, not 1019 eV !
Fn ~ 50 x Waxman-Bahcall
 AMANDA/RICE/EAS-sensitive !!
(AGHW, to appear)
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Tom Weiler, Vanderbilt University
AMANDA to 100 TeV
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Tom Weiler, Vanderbilt University
AMANDA/IceCube nm event
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Tom Weiler, Vanderbilt University
Xgal proton fit  huge n flux
low Xgal dominance flux,
with no evolution
WB fluxes
AGHW, hep-ph/04010003
x is pion energy/CR energy at source (1 for WB “limit”);
xz is cosmic evolution factor, 0.6 (no) to 3.0 (SFR)
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Tom Weiler, Vanderbilt University
Neutrinos versus Cosmic-Rays and Photons
ns come from central engines
- near Rs of massive BHs
- even from dense “hidden” sources
cf. ns vs. s from the sun
ns not affected by cosmic radiation
(except for annihilation resonance)
ns not bent by magnetic fields
- enables neutrino astronomy
Also, besides Energy and Direction, n’s carry flavor
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Tom Weiler, Vanderbilt University
n diagnostic of astro-engines:
pp vs. p 
The process ne+e--  W-- is resonant at 6.4 PeV;
IceCube will have flavor ID, and E/E of 25%,
and so can measure On-Res/Off-Res ratio.
pp make nearly equal + nm:nm:ne:ne = 2:2:1:1
 flavor democracy, ne = 1/6 total
p via + make +
 nm:nm:ne = 1:1:1 (no ne)
 ne = 1/15 total
IceCube can resolve this (AGHW, ArXiv this week)
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Tom Weiler, Vanderbilt University
Flavor ratio  Topology ratio Map
Beacom, Bell, Hooper, Pakvasa, TJW, 2003
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Tom Weiler, Vanderbilt University
The cosmic n flavor-mixing theorem
If theta32 is maximal (it is),
And if Re(Ue3) is minimal (it is),
Then nm and nt equilibrate;
Further, if initial ne flux is 1/3
(as from pion-muon decay chain),
Then all three flavors equilibrate.
ne:nm:nt = 1 : 1 : 1
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at Earth
Tom Weiler, Vanderbilt University
Democracy Broken:
1. n decay (15 minutes of fame)
2. Vacuum resonance
(MaVaNs, LIV vector)
3. Pseudo-Dirac n oscillations
4. Source dynamics (w/ Farzan)
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Tom Weiler, Vanderbilt University
Neutrino Decay -Models, Signatures, and Reach
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Tom Weiler, Vanderbilt University
“Essentially Guaranteed” High-Energy Galactic Neutrino
Flux
ctn = 10 kpc (En / EeV)
and
En / En ~ Q / mn ~ 0.8 x 10-3
 En ~ PeV, for En ~ EeV
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Tom Weiler, Vanderbilt University
Comparing to “guaranteed” cosmogenic flux, Galactic beam (here) is higher !
“More Guaranteed”
Icecube atmos background in 1o circle is just 1.5events/yr,
 3.5 events offers 95% CL detection in 1 yr;
Calculated signal is 4 nm /yr and 16 ne+nt showers/yr.
Conclude that in a few years, IceCube attains 5s
discovery sensitivity for Fe  n  ne  nm,
Providing “smoking ice” for GP neutron hypothesis.
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Tom Weiler, Vanderbilt University