PDA

View Full Version : Jerry's Take on IceCube null result



Jerry
2012-Feb-19, 06:44 AM
"http://arxiv.org/abs/1202.3283 Recent Results of the ANTARES Neutrino Telescope
Juan Josť HernŠndez-Rey

A quick read on what ANTARES has found. Basically, nothing from cosmic sources, although ANTARES is operating at nominal performance levels."
Disappointing. This and early Ice Cube results do not bode well for the neutrino theories these depthy telescopes hoped to flesh out. What next?

Tensor
2012-Feb-19, 06:51 AM
"http://arxiv.org/abs/1202.3283 Recent Results of the ANTARES Neutrino Telescope
Juan Josť HernŠndez-Rey

A quick read on what ANTARES has found. Basically, nothing from cosmic sources, although ANTARES is operating at nominal performance levels."
Disappointing. This and early Ice Cube results do not bode well for the neutrino theories these depthy telescopes hoped to flesh out. What next?

Jerry, how come these results are disappointing, and don't bode well. But, the lack of detection of gravity waves are an automatic "the gravitational wave detectors aren't going to detect anything", GR is wrong?

Gsquare
2012-Feb-20, 02:36 PM
I've never seen a list of the candidate sources. How many are continuous and how many are temporal and are any witin a few hundred light years.??
Just wondering..Null results gets my Holmes Detector going.:))

G^2

antoniseb
2012-Feb-20, 03:13 PM
I've never seen a list of the candidate sources. ...
What we'd be looking at as candidates are things that produce many high energy neutrinos, perhaps directed at us, or perhaps even more, just going everywhere. Such things might be relatively nearby GRBs, or perhaps active galactic nuclei (such as M87 or Cen A), or perhaps micro-quasars, or nearby supernovae.

The fact is that most models say that we should not quite yet be detecting any of these, unless we got very lucky with when a relatively close or intense event occurred.

Tensor
2012-Feb-20, 10:11 PM
Have any neutrino detectors detected anything, besides the burst from 1987a?

ngc3314
2012-Feb-20, 11:03 PM
Sun, Earth, atmospheric neutrinos produced in interactions with cosmic rays, nuclear reactors, and particle accelerators.

antoniseb
2012-Feb-21, 01:04 AM
Have any neutrino detectors detected anything, besides the burst from 1987a?
IceCube and Antares detect extremely high energy neutrinos, and they DO detect them. What they haven't done is detect any of these high energy neutrinos from a specific object or event. While it is interesting to know that there are cosmic sources producing these things, we would LOVE to get some good stats on the high energy processes in GRBs among other things.

Tensor
2012-Feb-21, 02:08 AM
Sun, Earth, atmospheric neutrinos produced in interactions with cosmic rays, nuclear reactors, and particle accelerators.

Yeah, I should have specified cosmic sources.

Tensor
2012-Feb-21, 02:10 AM
IceCube and Antares detect extremely high energy neutrinos, and they DO detect them. What they haven't done is detect any of these high energy neutrinos from a specific object or event. While it is interesting to know that there are cosmic sources producing these things, we would LOVE to get some good stats on the high energy processes in GRBs among other things.

I thought there were detection, but not specific events. Thanks for the confirmation.

Jerry
2012-Feb-21, 05:47 AM
Jerry, how come these results are disappointing, and don't bode well. But, the lack of detection of gravity waves are an automatic "the gravitational wave detectors aren't going to detect anything", GR is wrong?

It is disappointing we have not been able to isolate cosmic neutrinos from local sources - this is what these ultra-sensative large arrays are hoping to be able to isolate. Yes, a local supernova event should light these detectors up like a christmas tree...or will it? These are the first neutrino dectectors that have enough resolution to find distant point sources.

Onl the other hand, we are on about the fifth generation of failed gravitational wave detectors; and each set of expectations has been parred down from prior failures. That is about two generations beyond where Einstein declared it was stupid to keep repeating failed Michelson-Morley experiments. So what is good for the goose...

Meanwhile:

*Dark Matter*
http://arxiv.org/abs/1202.4179 Two papers on Dark Matter caught me today. First this one about the rejection of the idea that neutral muons (and other things) are polluting the DAMA data at Gran Sasso. This experiment looks at the daily flux of 2-6 keV events inside roughly a ton of Sodium-Iodide crystals down in a cave, and looks for the annual change as the Earth goes around the Sun sometimes with the presumed flow of Dark Matter around the galaxy, and sometimes against it... and a difference in flux IS observed. This paper goes through the list of non-Dark Matter alternatives and shows why they aren't causing the signal.

Funny that...is...isn't that what Michelson and Morley were hoping to find? I'm kidding - they were expected a similar signal in EMF broadbands. Nonetheless, i don't remember anyone predicting DAMA data looking like this would expose dark matter. It isn't nearly as bad as suggesting DM particle collisions produce other unexpected particles; but I get to suspect the usual unexpected suspects.