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Particle Physics Opportunities with the Next Generation. Ultra High Energy Neutrino Telescopes. David Saltzberg.
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David Saltzberg
University of California, Los Angeles
Aspen Winter Conference
“The Highest Energy Physics”
February 17, 2005
Particle Physics with a Tevatron
Teraton
Homestake
Super-K
SN1987AKamiokande
dispersion
ν
mass limits
constrains
ν
decay scenarios
ν
weak eigenstates
mass eigenstates
ν
mass
z
Exotic
Physics:
UHECR would result from decays of super-
heavy particles.
z
Example: Grand Unified Supersymmetric Theories:
Is its lifetime comparable to age of universe or is it ~
sec?
Loophole—produce them continuously by “topological defects
” remaining from
Big Bang
X
25
eV
`EM’
`weak’
strong
13
19
25
(eV)
z
Some specific models
Ê
Bhattacharjee, Hill, Schramm PRL 69, 567, (1992)
Ê
Protheroe & Stanev PRL 77,3708 (1996)
Ê
Sigl, Lee, Bhattacharjee, Yoshida PRD 59,043504 (1998)
Ê
Barbot, Drees, Halzen, Hooper, PLB 555, 22 (2003)
z
Basic ideas
Were attractive to circumvent GZK cutoff for UHE cosmic rays.
Topological defects could be monopoles, superconducting cosmicstrings, domain walls
Generally these models produce hard neutrino spectrum: ~ E
-(1-1.5)
“bottom-up” scenarios are more steeply falling: E
to E
not ruled out by lower energy telescopes
constrained by MeV—GeV isotropic photon fluxes
Neutrino flux vs. energy sensitive to source evolution vs. z of TD’s.
z
Possible point of confusion:
Models give brightness
But, experiments measure intensity
from P. Gorham
n
p e
ν
ν
e
n
p
Most commonly used:Ghandhi et al., Astropart. Phys. 5, 81 (1996):
z
Probing interactions at high CM
Ê
E
cm
= [2 m
p
E
ν
]
1/
Î
150 TeV for E
ν
= 10
19
eV
Ê
σ
SM
(
ν
+N) ~ 10
£
σ
SM
(p +N)
z
Large extra dimension models could enhance
ν
cross section
Ê
Gravity could become strong at E
CM
=M
D
Ê
Non-perturbative effects could produce KK-exitations, string excitation, pea- branes, micro-BH above E
CM
z
Astrophysics and laboratory limits still allow
Ê
n=4, M
D
10 TeV
Ê
n¸ 5 M
D
1 TeV
D
~1 TeV, n~6-7:
SM
Alvarez-Muniz,Feng,Halzen,Han,HooperPRD65, 124015 (2002)
Anchordoqui et al., PRD66, 103002 (2002)
10
10
10
(cm σ
2
)
10
19
10
17
10
21
E
ν
(eV)
SM
z
Caveat: not all energy goes into BH or excitation, and need minimum energy for
classical BH formation. z
UHE
ν
cross sections could be up to ~100£ Standard Model
Anchordoqui,Feng,Goldberg,Shapere,PRD65, 103002 (2002)
Wick, Kephart, Weiler, Biermann
Ê
produce EM showers along path by pair-production, photo-nuclear
Ê
continuously produces shower along its path
Æ
unique
signature
3
Ê
SalSA could do ~10-100 times better:
Ê
sensitive for M
mp
up to 10
23
eV, far beyond production at
accelerators.
Ê
Flux limit better than typical searches
z
Critical parameter for neutrino oscillations and decay is proper time, L/E.
Ê
Solar neutrinos: 150,000 km/5£
6
eV = 30 m/eV
Ê
“SalSA” neutrinos from 4 Gpc/
17
eV = 10
9
m/eV
z
No SM
ν
decay from SM on these time scales
Ê
However,
ν
!
ν
(J= Majoran)
Ê
Flavor ratios would be from lightest mass eigenstate
z
Beacom,Bell, Hooper, Pakvasa, Weiler
z
ν
e
:
ν
μ
:
ν
τ
z
~1:1:1!
5:1:
Excess charge moving faster than
c/n
in matter emit Cherenkov
Radiation
In dense material R
Moliere
~ 10cm.
λ
<<R
Moliere
(optical case), random phases
⇒
P
∝
N
λ
R
Moliere
(microwaves), coherent
⇒
P
∝
N
2
ν
ν
ν
d
CR
∝
Confirmed with Modern simulations + Maxwell’s equations:
(Halzen, Zas, Stanev, Alvarez-Muniz, Seckel, Razzaque,
Buniy, Ralston, McKay …)
Each charge emits field |E|
e
ik•r
and Power
tot
(^2)
Another
Good Idea from Askaryan (II):
Acoustic Detection
(1957)
sim @1km perp.
z
Verified in beamtests at Brookhaven (J. Learned, L. Sulak…)
z
“Radio in Ice Experiment”
z
Dipoles (100-1000 MHz) on AMANDA strings@ South Pole
z
200 x 200 x 200 meter array
z
Uses long attenuation length (view to ~ 7km)
z
E
ν
~
17
eV
z
[V
∆Ω
]» 10 km
3
-sr
z
Status
Ê
published on 333 hour dataset
Ê
results from 3-year dataset
Ê
datataking ongoing
z
Expected events in 5 years:
Ê
~9 TD events
Ê
2-7 GZK events
Ê
~3 GRB/AGN events
Candidate event
I. Kravchenko,
et al
., ICRC-03, astro-ph/
et al
., PRL 93, 041101 (2004)
Two antennas at JPL’sGoldstone, Calif. TrackingStation z
limits on >
20
eV
ν
’s
z
regolith atten. len. ~20 m
z
~123 hours livetime
z
eff
~600 km
3
-sr
z
datataking complete
Earlier experiment: 12 hrs using single Parkes 64m dish inAustralia: T. Hankins
et al
., MNRAS 283, 1027 (1996)
