Andrew Hopkins- The Cosmic Star Formation History and the Diffuse Supernova Neutrino Background
Diffuse supernova neutrinos at underground laboratories
description
Transcript of Diffuse supernova neutrinos at underground laboratories
Diffuse supernova neutrinos at underground
laboratoriesCecilia Lunardini
Arizona State University And RIKEN BNL Research Center
INT workshop “Long-Baseline Neutrino Physics and Astrophysics”
• Motivations • Current status• The future:
– Detection potential– What can we learn?
• Extras: what else?
C. Lunardini, arXiv:1007.3252 (review)
Diffuse neutrinos from all SNe
• Sum over the whole universe:
Supernovae
S. Ando and K. Sato, New J.Phys.6:170,2004.
Motivations
Clip art from M. Vagins
Sooner and more• Faster progress
– Alternative to a galactic SN! • ~20 events/yr/Mt everyday physics!
• New science– What’s typical ?– New/rare SN types– Cosmological Sne
• Physics in the 10-100 MeV window?
Current status
The “ingredients”
Cosmological rate of
supernovaeNeutrino flux at
production +
Propagation effects:
OscillationsRedshift
….
Cosmology
Supernova rateRSN(z) ~RSN(0) (1+z)β , z<1
normalization uncertainThis work: β=3.28, RSN(0) = 10-4 Mpc-3 yr-
1
Beacom & Hopkins, astro-ph/0601463
From Star Formation Rate
From SN data
Original spectra
• Models: – Lawrence Livermore– Thompson, Burrows, Pinto (Arizona)– Keil, Raffelt, Janka (Garching)
• 3 1053 ergs , equipartitioned between 6 species
Keil,, Raffelt,Janka, 2003 Astrophys. J. 590 971
x=μ, τ
Flavor oscillations• Self-interaction + MSW (H) + MSW (L)
– Spectral swap
• Depend on θ13 and hierarchy– Normal (inverted): ∆m2
31>0 (∆m231<0)
Jumping probability, PH
Duan, Fuller, Quian, PRD 74, 2006
C.L. & A. Y. Smirnov, JCAP 0306, 2003
• p= 0 – 0.32 , p = 0 – 0.68
Chakraborty et al., hep-ph/08053131
Higher energy tail
DSNnF spectrumExponential decay with E
LL
TBP KRJ
Neutrinos, p=0.32 Neutrinos, p=0
C.L., in preparation
Upper limits and backgrounds
Energy window
SuperKamiokande (Malek et al., PRL, 2003):
Red dashed: HomestakeSolid, grey: Kamioka
anti-e flux: predictions
C.L., Astropart.Phys.26:190-201,2006
The future: detection potential
Detectiontechnology
mass Reaction Energy window
Events/(5 yrs)
Water Cherenkov
0.4 Mt Anti-nue, inverse beta,(90% eff.)
19 – 40 MeV
27 - 227
Water + Gadolinium(GADZOOKS)
0.0225 Mt Anti-nue, inverse beta(90% eff.)
11 – 40 MeV
4 - 17
Liquid Argon 0.1 Mt nue + Ar, CC(100% eff.)
19 – 40 MeV
6 – 28
Liquid Scintillator (LENA)
50 kt Anti-nue, inverse beta(100% eff.)
11 – 40 MeV
O(10)
Water Energy window Background/signal ~ 5
-6(at Kamioka)
Fogli et al., JCAP 0504, 002, 2005
Bulk of events missed
Large statistics: ~ 1-2 events/MeV/yr
GADZOOKS Energy window Background/signal<1
Invisible muons reduced to 1/5
Beacom & Vagins, PRL93, 2004
Larger energy window:
Bulk of events captured!
Modest statistics… Scaling to Mt??
LAr Energy window
Background/signal ~ 0.2-0.3
Bulk of events may be captured!
Statistics modest: ~0.2
events/yr/MeVScaling?
New!
C.L., in preparation
What can we learn?
Water+Gd: effective spectrum
Normalized to 150 events, b=3.28
C.L., Phys.Rev.D75:073022,2007
A step beyond SN1987A!
• Test SN codes of spectra formation, some oscillation effects, etc.
• 0.1 Mt yr :– Tests part of
parameter space– May not reach
SN1987A region
0.1 Mt yr
Yuksel, Ando and Beacom, Phys.Rev.C74:015803,2006
Chance to test b
r ~ 0.6 – 0.9
Normalized to 150 events
C.L., Phys.Rev.D75:073022,2007
New SN types: failed SNe• M > 40 Msun, 9-22% of all collapses
• Direct BH-forming collapse (no explosion):– Higher energies: E0 ~ 20 – 24 MeV
• For all flavors• Due to rapid contraction of protoneutron star before
BH formation
– Electron flavors especially luminous• (e- and e+ captures)
Liebendörfer et al., ApJS, 150, 263, K. Sumiyoshi et al., PRL97, 091101 (2006), T. Fischer et al., (2008), 0809.5129, K. Nakazato et al., PRD78, 083014 (2008)
– Progenitor: M=40 Msun, from Woosley & Weaver, 1995– “stiffer” eq. of state (EoS) more energetic neutrinos
Shen et al. (S) EoS
Anti-nue
nux
nueBH
NS
K. Nakazato et al., PRD78, 083014 (2008)
Number of events: water..• Best case scenario: 22% failed, S EoS
Total
Normal
Failed
C.L., arXiv:0901.0568, Phys. Rev. Lett., 2009, J. G. Keehn and C.L., in preparation
LAr• Bulk of events from failed SNe captured• Failed SN at least a 10% effect in energy window
J. Keehn & C.L., in preparation
Failed
Normal
Total
Reducing uncertainties• Precise SN rates coming soon from
astronomy
• Neutrino uncertainties more serious– SN modeling?– Galactic SN?
http://snap.lbl.gov/ http://www.jwst.nasa.gov/,
C.L., Astropart.Phys.26:190-201,2006
Extras
What else is there?
Neutrinos from solar flares?• LSD: 27 flares
examined in 3 years
• Mt-size advocated for detectionRelic SN, 1 year
Flare, best
Flare,conservativeErofeeva et al., 1988; Bahcall PRL 1988Kocharov et al., 1990, Fargion et al., 2008
Aglietta et al., 1990
Miro
shni
chen
ko e
t al.,
Spa
ce S
cien
ce R
evie
ws
91: 6
15–7
15, 2
000
Solar antineutrinos• Spin-flavor
oscillations– νe anti-νe
Rashba & Raffelt, Phys.Atom.Nucl.73:609-613,2010
Neutrinos from relic decay/annihilation
• χ ν + anti-ν• χ+ χ ν + anti-ν
Gamma rays
Yuksel & Kistler, PRD, 2007
Palomares Ruiz & Pascoli, Phys.Rev.D77, 2008Palomares Ruiz, Phys.Lett.B ,2008
MeV Dark Matter absorption
Kile and Soni, Phys.Rev.D80:115017,2009
Summary• DSNnF may be seen with few years running!
– 100 kt LAr : O(10) events– 0.4 Mt water : O(102) events
• New science:– Typical neutrino emission– Sensitive to failed Sne– Other physics in energy window?
• To advance further:– Resolve parameter degeneracies (theory)– reduce background at low E