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WIMP dark matter search is nearing the end. Race for more sensitive detector can't go on much more, because there is a fundamental limit: neutrino wall. No one

by sanxiyn 12y ago

WIMP dark matter search is nearing the end. Race for more sensitive detector can't go on much more, because there is a fundamental limit: neutrino wall. No one knows how to eliminate noise from neutrino, and now detectors are nearing sensitivity enough to detect neutrino from the Sun. Since neutrino from the Sun is the noise floor that can't be eliminated, below that even if there is a signal we can't find it. http://resonaances.blogspot.com/2014/02/weekend-plot-arms-race.html http://resonaances.blogspot.com/2014/02/weekend-plot-arms-ra...

tjradcliffe 12y ago
> even if there is a signal we can't find it Yet. Although I love the notion of "neutrino noise" there are always clever tricks. Twenty years ago I designed a reactor neutrino detector that suppressed the fireball neutron background using a variety of signal processing cuts, and we could actually tell when the reactor was on after a week or so of data collection despite the raw background being three or four orders of magnitude larger than the signal. I'm sure the people working on this have thought of the obvious (neutrinos from the sun have directionality and a particular spectral shape) but anyone familiar with the history of experimental physics won't say it's impossible to beat this limit. Just that it's a problem we haven't solved. Yet.
mapt 12y ago
The terrestrial search is nearing the end, but that's not necessarily the end for all of time, just the end for a few generations of particle physicists. We're at 1AU from the sun. Titan is at 10AU from the sun, has a thick atmosphere to aerobrake into, has remarkably varied topography (including pools of liquid one could submerge detectors in), and will have one hundredth the solar neutrino flux. Neptune is at 30 AU: Add another order of magnitude if you figure out how to work a gas giant to your ends (and a beer on me). If you can work in vacuum there's not only Triton, but with microgravity operations, the whole Kuiper Belt & Oort cloud out there to use as in-place shielding against GCRs.

by sanxiyn 12y ago

tjradcliffe 12y ago

> even if there is a signal we can't find it Yet. Although I love the notion of "neutrino noise" there are always clever tricks. Twenty years ago I designed a reactor neutrino detector that suppressed the fireball neutron background using a variety of signal processing cuts, and we could actually tell when the reactor was on after a week or so of data collection despite the raw background being three or four orders of magnitude larger than the signal. I'm sure the people working on this have thought of the obvious (neutrinos from the sun have directionality and a particular spectral shape) but anyone familiar with the history of experimental physics won't say it's impossible to beat this limit. Just that it's a problem we haven't solved. Yet.

mapt 12y ago

The terrestrial search is nearing the end, but that's not necessarily the end for all of time, just the end for a few generations of particle physicists. We're at 1AU from the sun. Titan is at 10AU from the sun, has a thick atmosphere to aerobrake into, has remarkably varied topography (including pools of liquid one could submerge detectors in), and will have one hundredth the solar neutrino flux. Neptune is at 30 AU: Add another order of magnitude if you figure out how to work a gas giant to your ends (and a beer on me). If you can work in vacuum there's not only Triton, but with microgravity operations, the whole Kuiper Belt & Oort cloud out there to use as in-place shielding against GCRs.