Geo-neutrino Working Group

Goals and Progress

10 December 2011- CIDER Workshop

Geo-neutrinologists

S Dye4, Y Huang6, W Gosnold7, C Jaupart5, V Lekic6, J-C Mareschal3, WF McDonough6, C Phaneuf3, W

Roggenthen8, R Rudnick6, S Shirey1, K Sims9, O Sramek6, S Zhong2

1. Carnegie Institution2. University of Colorado

3. GEOTOP4. Hawaii Pacific University

5. IPGP6. University of Maryland

7. University of North Dakota8. South Dakota School of Mines Technology

9. University of Wyoming

Geo-neutrino Projects

(Enomoto, Neutrino Sciences 2007)operating

Japan

operating

Italy

Canada

2013

Finland

20??

Hanohano 20??

KamLAND- operational in Japan

νe + p → n + e+

Reactor antineutrinoinverse beta

Primary Goal

• operating since 3/9/02• 1000 tonnes LS• 1879 PMTs

Geo-neutrino result Gando et al., 2011

3.49x1032 p-y

KamLAND Geo-nu Data

Geonu signal of ~100 eventscompeting with

large background

Uncertainty in geo-nu signal

limited by systematic

error

Borexino- operational in ItalyPrimary Goal

νe + e- → νe + e-

Solar neutrino-electron scattering

Geo-neutrino resultBellini et al., 2010

0.15 x 1032 p-y• operating since 5/16/07• 300 tonnes LS• 2200 PMTs • ~30% PC coverage

Borexino Geo-nu data

Geo-nu signal of ~10 events collected

in ~ 5% KamLAND exposure yet

similar precision:Controlled background

Uncertainty in geo-nu signal

limited by statistical

error

Observations & Model Predictions

Mantle signal- 10 ±11 TNUMhhomogeneous mantle = 11 ±13 TW

Mantle signal- 39 +27/-23 TNUMhhomogeneous mantle = 45 +32/-26 TW

KamLAND 2011 (Th:U=3.9) Borexino 2010 (Th:U=3.9)

Gando et al., 2011 Bellini et al., 2010

Mantle- Signal, Heat, Th:U

Mantle signal is key to resolving geological models but masked

by crust error

EH

CI

GP

Site-dependent Measurement Error

Error5% reactor15% crust

Geo-neutrino Working Group Progress

Kite and Lekic; Sramek et al. Mareschal, Phaneuf, Jaupart

ULVPs thermal or chemical? Crust flux model discrepancy

Geo-neutrino Working Group Goals

• Identify and implement projects that maximize geological information from terrestrial antineutrino observation– Geoscience community- seismology, heat flow,

geochemistry, geophysics, mineral physics, +…– Improve precision of crust flux estimates

• “see” mantle from continents– Determine exposures required to test hypotheses

• Super-plumes thermal or compositional• Crust flux predicted by CRUST 2.0 or heat flow• More…

– + ???