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Radio detection of UHE neutrinos. E. Zas, USC Leeds July 23 rd 2004. J. Alavarez-Muñiz F. Halzen E. Marques T. Stanev R. Vazquez E. Zas. Contents:. Why UHE n? How does it work? What are the advantages? Which experiments ?. Neutrino - Cosmic Ray connection. - PowerPoint PPT Presentation
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Radio detection of UHE neutrinos
E. Zas, USC
Leeds July 23rd 2004
EZ Leeds 2004 Radio Detection 2
Contents:
•Why UHE
•How does it work?
•What are the advantages?
•Which experiments
J. Alavarez-MuñizF. HalzenE. MarquesT. StanevR. VazquezE. Zas
EZ Leeds 2004 Radio Detection 3
Neutrino - Cosmic Ray connection
• CR knwn to exist with E>1020 eV
• UHECR mechanisms produce • By fragmentation [“Top Down” Z-burst ...]
• By interaction [Fermi]• With matter
• With radiationInteractions with CMB => GZK neutrinos
There must be UHE neutrinos!
EZ Leeds 2004 Radio Detection 4
The / p flux ratio: A step towards UHECR source origin
• Acceleration • Fragmentation
p+
p+p
+ 0 p
p ::
0.09 : 2 : 6
p : 1 : 6
q q X
p :0 :+/-
0.03 : 0.3 : 0.65
+
pe e+
::e
2 : 4:2
( ) ( )
EZ Leeds 2004 Radio Detection 5
•GZK neutrino flux depends on:
•Cosmic Ray spectrum
•Source distribution
•Maximum redshift
•Source evolution
Target: The GZK -spectrum
EZ Leeds 2004 Radio Detection 6
CR
Flu
x / R
efer
ence
Flu
x
D.Gonzalez,RAV,EZ (in prep)
p-spectrum afterCMB interactions
ONE source onlyUniform Distribution UD + strong evolution
____________
E-2
EZ Leeds 2004 Radio Detection 7
CR
Flu
x / R
efer
ence
Flu
xE-2
D.Gonzalez,RAV,EZ (in prep)
_________U Dis+evol_________Unif Distr_________one source
EZ Leeds 2004 Radio Detection 8
P &
-F
lux
/ Ref
eren
ce F
lux
D.Gonzalez,RAV,EZ (in prep)
_________U Dis+evol_________Unif Distr_________one source
E-2
EZ Leeds 2004 Radio Detection 9
Radio pulses from showers: Why?
Coherent
Radiation
Radio wavelength Emission length
wl
• SIGNAL POWERElectric Field ~ Q
• STABILITYTo shower fluctuations
• INFORMATION• Spatial distribution
• Frequency Spectrum
EZ Leeds 2004 Radio Detection 10
Cherenkov in radio (Askary’an 1960)
Wavelength (>> l,w e- and e+ cancel !!
But what about excess Ne--Ne+?
•e, interactions have charge symmetry•But matter only has electrons!!
•Interaction with matter electrons
Askary’an predicted ~10% charge excess
EZ Leeds 2004 Radio Detection 11
Processes contributing to the excess charge
Compton e-
Annihilation
media electrons
e-
e+
Möller
e-
e-
Bhabha
e-
e+
e-
e+
EZ Leeds 2004 Radio Detection 12
ZHS:FH,TS,EZ, PRD(91)
ICE
EZ Leeds 2004 Radio Detection 13
)(
11)(
)()(
vki
eve
RiE
tvkiphaseoveralli
Calculate radio pulse interference
tn
tntv
)cos1(
)cos1(sin
tracklength
if =0 or =c
or t=0tv
(Fraunhofer limit)
EZ Leeds 2004 Radio Detection 14
EZ Leeds 2004 Radio Detection 15
EZ Leeds 2004 Radio Detection 16
• |E| Ne-Ne+ Scaling
• Ne-Ne+ ESHOW
Signal Power
Radio Pulse Power |E|2 E2SHOW
EZ Leeds 2004 Radio Detection 17
EZ Leeds 2004 Radio Detection 18
EZ Leeds 2004 Radio Detection 19
EZ Leeds 2004 Radio Detection 20
EZ Leeds 2004 Radio Detection 21
The slit diffraction analogy
If current is “thin”:
ikzezdzQR
iE )()(
cnk
)cos1(
Kind of FT with
EZ Leeds 2004 Radio Detection 22
• c
Stability
)(zdzQE
(because k=0)
EZ Leeds 2004 Radio Detection 23
•Calculations of UHE with hybrid code with LPM effect!!
•Electromagnetic showers ~E-1/3 above 10 PeV
•Hadronic Showers hardly any elongation up to 100 EeV
• showers measure y?
EZ Leeds 2004 Radio Detection 24
EZ Leeds 2004 Radio Detection 25
EZ Leeds 2004 Radio Detection 26
EZ Leeds 2004 Radio Detection 27
Natural transparent media• ICE:
• Antarctica– RICE (array buried)– ANITA (balloon)
• Greenland– FORTE (satellite)
• SALT:•
Domes explored– SALSA
• MOON REGOLITH:• Radiotelescopes
– GLUE • Radiotelecope array
– LUNASKA (ska)• ATMOSPHERE:
• Antenna array– LOFAR
Coherent radio detection: -experiments
EZ Leeds 2004 Radio Detection 28
Askary’an effect confirmed: SLAC
P.Gorham, D.Saltzberg et al. PRL (2000)
EZ Leeds 2004 Radio Detection 29
EZ Leeds 2004 Radio Detection 30
Coherence! |E| Esh
|E()| spectral agreement
EZ Leeds 2004 Radio Detection 31
• Radio Technique has an enormous potential• To detect highest energy events
• To get detail about showers
• To cover large surfaces
• There are many projects under consideration
• It is worth pursuing them
• It is likely that radio provides the next step in the search for UHE radiation
Summary and conclusion:
EZ Leeds 2004 Radio Detection 32
Both Cosmic Ray & -detector
CR
Different geometries
EZ Leeds 2004 Radio Detection 33
EZ Leeds 2004 Radio Detection 34Complex acceptance geometry
MOONJAlvarez Muñiz
EZ Leeds 2004 Radio Detection 35
EZ Leeds 2004 Radio Detection 36
FORTE low frequency search system for transients
(weather measurements)
central :20-300 MHz bandwith: 22 MHz 5 subbands coincidences
Lehtinen, PG et al. astro-ph/0309656
Data Sep 97-Dec 99
2003 BOUND
EZ Leeds 2004 Radio Detection 37
EZ Leeds 2004 Radio Detection 38
P. Gorham, et al. astro-ph/0310232
EZ Leeds 2004 Radio Detection 39
EZ Leeds 2004 Radio Detection 43
GZ
K
-Flu
xE-2
D.Gonzalez,RAV,EZ (in prep)
_________U Dis+evol_________Unif Distr_________one source