Nuclear decay rates possibly correlate with distance from Sun

[Mk]

http://arxiv.org/abs/0808.3283

Unexplained periodic fluctuations in the decay rates of Si-32 and Ra-226 have been reported by groups at Brookhaven National Laboratory (Si-32), and at the Physikalisch-Technische-Bundesandstalt in Germany (Ra-226). We show from an analysis of the raw data in these experiments that the observed fluctuations are strongly correlated in time, not only with each other, but also with the distance between the Earth and the Sun. Some implications of these results are also discussed, including the suggestion that discrepancies in published half-life determinations for these and other nuclides may be attributable in part to differences in solar activity during the course of the various experiments, or to seasonal variations in fundamental constants.

This is weird as hell. As far as I knew, nuclear decay rates were not affected by anything, except beta decay under electromagnetic fields. This could possibly have huge consequences in other sciences. Personally, I immediately went to post this in Earth. Paleoclimatologists collect data over hundreds to millions of years based on isotope ratios and nuclear decay rates. Anthropologists, archeologists, geologists— they all do as well, but who knows!

In summary, we have presented evidence for a correlation between changes in nuclear decay rates and the Earth-Sun distance. While the mechanism responsible for this phenomenon is unknown, theories involving variations in fundamental constants could give rise to such effects.

By that they mean the fine structure constant. They cite this paper: http://arxiv.org/abs/0806.4317

They also cite this paper in saying:
http://arxiv.org/abs/0808.3156

These results are also consistent with the correlation between nuclear decay rates and solar activity suggested by Jenkins and Fischbach [18] if the latter effect is interpreted as possibly arising from a change in the solar neutrino flux. These conclusions can be tested in a number of ways. In addition to repeating long-term decay measurements on Earth, measurements on radioactive samples carried aboard spacecraft to other planets would be very useful since the sample-Sun distance would then vary over a much wider range. The neutrino flux hypothesis might also be tested using samples placed in the neutrino flux produced by nuclear reactors.

Interesting, all these papers came out at about the same time in 2008. Nice stuff. I'm not a frequent poster in this forum, but I thought it would be placed well here and get some good discussion on these three papers. If it should be moved by a moderator, then go ahead and move it.

 

[arivero]

http://arxiv.org/abs/0808.3283
This is weird as hell. As far as I knew, nuclear decay rates were not affected by anything, except beta decay under electromagnetic fields.

I guess that this is the conjecture under test: that beta decay rates could be sensible enough to the variation of solar neutrinos. Weird indeed.

 

[cesiumfrog]

Has the paper been (expert) peer reviewed? (A little thing like that doesn't stop slashdot running with it of course..) Any attempts at running an identical apparatus in the opposite hemisphere?

 

[CarlB]

Another, somewhat less convincing, recent article with some of the same authors is:

Perturbation of Nuclear Decay Rates During the Solar Flare of 13 December 2006
Jere H. Jenkins, Ephraim Fischbach
http://arxiv.org/abs/0808.3156

As far as the validity of the paper, they've got 6 authors, which is a bit too many to overlook something obvious, but only Jenkins has a lot of papers to his credit.

I can see how a neutrino flux might modify beta decay; it would be a sort of lasing effect if the frequencies were right. But I don't see how neutrinos could possibly effect a decay that emitted an alpha particle, unless it was a cascade or something like that, but that's not the case, Ra-226 is a straight alpha emitter:
http://en.wikipedia.org/wiki/Radium

Rather than neutrino flux, I would think that a dependence on gravitational potential would be more likely, especially given that the rate has a small phase difference from the distance to the sun (a lag).

 

[Vanadium 50]

I think it's far more likely that the authors are observing a seasonal variation in detector performance.

There are two things in the back of my mind when I read this. One is that the authors were re-analyzing someone else's data: they weren't there when it was taken. That immediately puts them at a disadvantage. (In fact, it's even possible that this effect was noticed by the original experimenters, and the reason identified).

The other is that Fischbach has a track record of finding dramatic new physics effects in other people's data - effects that subsequently are shown not to exist.

 

[vanesch]

I think it's far more likely that the authors are observing a seasonal variation in detector performance.

This is also what came to my mind. I once had an unexpected variation in a detector efficiency with a time constant of a few hours, and it turned out to be perfectly correlated with the airconditioning which switched on and off to keep the temperature about constant (but nevertheless, the 0.5 degree variation or so was noticable).

That said, in the paper, they compare to a reference each time, which seems to have remained flat, so in principle this has been taken into account...

 

[CarlB]

In addition, Fishbach has a paper claiming that the neutrinos weigh at least 0.4 eV (snicker). But there are a bunch of other authors.

 

[arivero]

I think it's far more likely that the authors are observing a seasonal variation in detector performance.

There are two things in the back of my mind when I read this. One is that the authors were re-analyzing someone else's data: they weren't there when it was taken. That immediately puts them at a disadvantage. (In fact, it's even possible that this effect was noticed by the original experimenters, and the reason identified).

He argues that it is different latitude; but one could be safer if it were different hemisphere. If they are in the same day/night pattern, I vote for radiation and consum patterns from the light bulbs/discharge tubes. The air conditioning system is also a suspect, yes.

The other is that Fischbach has a track record of finding dramatic new physics effects in other people's data - effects that subsequently are shown not to exist.

There is a scent of almost-recursivity in this research: Do you mean that there is a pattern in Fischbach data ?

 

[arivero]

I can see how a neutrino flux might modify beta decay; it would be a sort of lasing effect if the frequencies were right. But I don't see how neutrinos could possibly effect a decay that emitted an alpha particle, unless it was a cascade or something like that, but that's not the case, Ra-226 is a straight alpha emitter:
http://en.wikipedia.org/wiki/Radium

Perhaps an increase in the phase space available for disintegration? No sure, but for fision there is a peculiar colective phenomena around: the lower peak, corresponding to the more abundant subproduct, lives at 81 GeV (told at https://www.physicsforums.com/showthread.php?t=227263 ). In any case, in the NZ plot you can see that the other huge peak in the total collection of measured beta decays corresponds to the corner of the theoretical alpha line, next to the magic N=82.

Rather than neutrino flux, I would think that a dependence on gravitational potential would be more likely, especially given that the rate has a small phase difference from the distance to the sun (a lag).

Even -Lubos labeled me recently as an archetypal model of gullibility- I myself am unable to see how a grav variation could work. Next step is to look for tidal patterns.

 

[Vanadium 50]

That said, in the paper, they compare to a reference each time, which seems to have remained flat, so in principle this has been taken into account...

The BNL work compares Si-32 to Cl-36. Si-32 is a beta emitter, and Cl-36 decays by K-capture most of the time, with a tiny fraction of positron emission. So you will have different energy spectra, a different particle mix, and a different number of Auger electrons. A subtle difference in response is not hard to imagine.

Note that the original experimenters didn't have to worry about this, since over a multiyear run these effects would average out.

 

[sanman]

Decay Rate Variance Claimed

A pair of researchers are claiming to have found variance in alpha decay rate, which they have correlated with solar neutrinos:

http://physicsworld.com/cws/article/news/36108

Are they onto something, or just barking up the wrong tree?

 

[humanino]

You've not checked, have you ?
[thread=252518]Nuclear decay rates possibly correlate with distance from Sun[/thread]

 

[hamster143]

The most likely explanation is an imperfection in their experimental setup (either the clock or the detector) that makes readings depend on an external factor.

As far as correlations with solar flares, their chart is not very convincing. They should set up two systems in two different rooms (different buildings, if possible) and see if they get strong correlation between decay rates. If there is, then you can search for an external factor that affects decay rates - solar flares, neutrinos, axion flux, etc.

 

[Vanadium 50]

They should set up two systems in two different rooms (different buildings, if possible) and see if they get strong correlation between decay rates.

As mentioned in the other thread, this is impossible. The authors did not do the experiment; they are analyzing someone else's experiment.

 

[jtbell]

You've not checked, have you ?
[thread=252518]Nuclear decay rates possibly correlate with distance from Sun[/thread]

Um, that's this very thread.

Or did someone merge two threads?

 

[Vanadium 50]

The threads were merged.

I looked at the solar flare data and find it completely unconvincing. I see the decay rate bouncing all over the place, and sometimes this bouncing happens to be near a solar flare. The authors assume they have no systematic uncertainties, which is clearly not the case if you ask how well the off-flare data fits the curve.

 

[Saul]

It is interesting to note that there is a phase lag. That is to say there is a delay in the affect to reach peak and there is a delay in the affect to reach minimum. That observation supports the assertion that there is a build up and a build down associated with what every is causing what is observed. One hypothesis presented in the paper is that solar neutrinos somehow change nuclear decay rates. A problem with that hypothesis is that as neutrinos travel at the speed of light and do not build up or build down, there would be no delay if neutrinos were the cause. The neutrino hypothesis does not explain the phase lag.

 

[Saul]

We were discussing possible observational evidence of variance of fine structure with redshift. I see there is a reference to fine structure changes and scalar fields in this paper.

As noted above there is evidence of a time lag in the observational change in the nuclear decay rate where the strongest effect occurs after the Earth reaches aphelion or perihelion. A lag in the affect points to some other cause than neutrinos as neutrinos are thought to travel at the speed of light.

A second observation point that points away from the neutrino mechanism is the nuclear decay change is affecting both beta and alpha decay, beta decay is not affected by neutrinos.

I see the authors are proposing a solar created scalar field as a possible mechanism to explain the effect. That would explain the time delay in the mechanism and why it affects both alpha and beta decay.

I see a subsequent paper that notes there is a change in the decay rate prior to a solar flare.

Following the solar scalar field hypothesis, to explain a change in nuclear decay rates prior to a solar flare, the hypothesis would be the scalar field varies prior to the solar flare and the variance in the scalar field is perhaps related to what is causing the solar flare.

Thinking along the line of a scalar field as a possible mechanism it would be interesting to ask does the scalar field show long term variance?

If you think along that the hypothesis of the scalar field hypothesis rather than the neutrino line, then observations of the nuclear rate dependency and the sun Earth distance are also dependent on the long term evolution of the large solar scalar field. (i.e. The point is that the observed affect over decades, centuries, and millennium will not necessarily be constant and hence may be discounted as insignificant because of the observational period in question.)

I have looking for other astronomical observational evidence which might provide support for a hypothesis along that line and insight into how the mechanism might work. I have found some material concerning Lithium deficient stars and planetary formation which is interesting. The hypothesis is that there are different types of stars and the Lithium deficiency which occurs in roughly 7% of stars and a mechanism to create a hypothesized scalar field would be related to planetary formation.

I started researching solar magnetic affects CME and solar flares looking for a mechanism that could cause possibly cause observed large geomagnetic inclination changes (the orientation of the geomagnetic field abruptly changes and there is some change in the intensity of the geomagnetic field at the time of the event) changes in the Earth geomagnetic field referred to as archeomagnetic jerks. (Archeomagnetic jerks are different than geomagnetic jerks which are rapid changes to the geomagnetic field. Archeomagnetic jerks are large inclination changes in the geomagnetic field and are called archeomagnetic jerks as one of analysis tools is the study of ancient pottery to determine the orientation and the intensity of the geomagnetic field at the time at the time the pottery has formed.) There have been 10 archeomagnetic jerks observed in the last 2000 years.

Following the line of thought of a scalar field one would expect changes in the size of the Earth's ionosphere which correlate with changes in the solar magnetic cycle which I see are also observed.

http://arxiv.org/PS_cache/arxiv/pdf/0808/0808.3283v1.pdf

Evidence for Correlations Between Nuclear Decay Rates and Earth-Sun Distance

The preceding considerations, along with the correlations evident in Fig. 4, suggest that the time- dependence of the 32Si/36Cl ratio and the 226Ra decay rate are being modulated by an annually varying flux or field originating from the Sun, although they do not specify what this flux or field might be. The fact that the two decay processes are very different (alpha decay for 226Ra and beta decay for 32Si) would seem to preclude a common mechanism for both. However, recent work by Barrow and Shaw [12, 13] provides an example of a type of theory in which the Sun could affect both the alpha- and beta-decay rates of terrestrial nuclei. In their theory, the Sun produces a scalar field _ which would modulate the terrestrial value of the electromagnetic fine structure constant _EM. This could, among other effects, lead to a seasonal variation in alpha and beta decay rates, both of which are sensitive to _EM [14]. We note from Fig. 3 that the fractional difference between the 226Ra counting rates at perihelion and aphelion is _ 3 × 10−3, and this would require that the coupling constant k_ of _ to _EM should be k_ _ 3 × 106.

This experiment, which extended over 15 years, overlapped in time with the BNL experiment for approximately 2 years, and exhibited annual fluctuations in the 226Ra data similar to those seen at BNL. Figure 3 exhibits the PTB data as a 5 point rolling average, and it is evident from the figure that the PTB data closely track the annual variation of 1/R2. The Pearson correlation coefficient r for the data in Fig. 3 is r=0.66 for N=1968 data points, corresponding to a formal probability of 2×10−246 that this correlation could arise from two data sets which were uncorrelated. As in the case of the BNL data, there is also a suggestion of a phase shift between 1/R2 and the PTB data (see below), although this phase shift appears to be smaller than for the BNL data.

 

[CarlB]

The surprise is that alpha decay rates would be modified; beta and anti-beta decay seem more likely to have something to do with anti-neutrinos and neutrinos (via some sort of stimulated emission of radiation). One of the references I saw proposed that the alpha decay rates were not modified; instead, what was being seen was an influence on the decay of the daughter products. The influenced alpha decay mentioned was Ra 226. The (>99%) decay chain is:

88 Ra 226 alpha decays to 86 Rn 222; 1,601 years

86 Rn 222 alpha decays to 84 Po 218; 3.8 days

84 Po 218 alpha decays to 82 Pb 214; 3.1 minutes

82 Pb 214 beta minus decays to 83 Bi 214; 26.8 minutes

83 Bi 214 beta minus decays to 84 Po 214; 19.9 minutes

84 Po 214 alpha decays to 82 Pb 210; 164 microseconds

82 Pb 210 beta minus decays to 83 Bi 210; 22.3 years

83 Bi 210 alpha decays to 81 Tl 206; 3 million years

81 Tl 206 beta minus decays to 82 Pb 206; 4.2 minutes

82 Pb 206 is stable

In the above chain, 82 Pb 210 with a half-life of 22.3 years would tend to build up as all the isotopes higher up the decay chain have much much shorter half lives. So as a pure sample of Ra 226 ages (google "secular equilibrium"), it will build up 82 Pb 210 which decays by beta minus with a half life long enough to see a yearly influence. And then 83 Bi 210, on the scale we're looking at, is essentially stable.

I got the above data from:
http://education.jlab.org/itselemental/index.html

 

[Saul]

This is a new paper by a separate set of authors concerning the alleged annual variation of nuclear decay rates. The conclusion of the study is that the effect is real however additional investigation is required to determine its cause.


http://arxiv.org/PS_cache/arxiv/pdf/1007/1007.0924v1.pdf

Power Spectrum Analyses of Nuclear Decay Rates

We provide the results from a spectral analysis of nuclear decay data displaying annually varying periodic fluctuations. The analyzed data were obtained from three distinct data sets: 32Si and 36Cl decays reported by an experiment performed at the Brookhaven National Laboratory (BNL), 56Mn decay reported by the Children’s Nutrition Research Center (CNRC), but also performed at BNL, and 226Ra decay reported by an experiment performed at the Physikalisch-Technische-Bundesanstalt (PTB) in Germany. All three data sets exhibit the same primary frequency mode consisting of an annual period.

Additional spectral comparisons of the data to local ambient temperature, atmospheric pressure, relative humidity, Earth-Sun distance, and their reciprocals were performed. No common phases were found between the factors investigated and those exhibited by the nuclear decay data. This suggests that either a combination of factors was responsible, or that, if it was a single factor, its effects on the decay rate experiments are not a direct synchronous modulation. We conclude that the annual periodicity in these data sets is a real effect, but that further study involving additional carefully controlled experiments will be needed to establish its origin.

Here, the unexplained fluctuations were observed in the 56Mn decay data (a _−-decay) and exhibited a seasonal difference of approximately 0.5% between the winter and summer months. In addition to the consideration of changes in counting efficiencies, and the contribution from the low energy component of the neutron spectrum, all other possible causes of the seasonal variation focused on effects that would impact neutron emission rates. Ultimately these were excluded since none could produce the observed variation, nor explain why no oscillations were observed in 137Cs.

The inference from our analysis that different nuclei may be affected differently by an external source could help to explain recent papers by Norman et al. [10] and Cooper [11] who have set limits on possible variations in the decay rates of several nuclides. Since the phases of the various nuclides summarized in Table 2 differ sufficiently from that of 1/R2, failure to take them into account masks the statistically significant annual variation present in the data of Norman et al. [10, 25]. More generally, it is reasonable to suppose that the same complex details of nuclear structure (e.g. nuclear wavefunctions, angular momentum selection rules, etc.), which are responsible for the fact that halflives vary from fractions of a second to tens of billions of years, could also affect the response of different nuclei to some external influence.

 

[Subluminal]

In the article at http://physicsworld.com/cws/article/news/36108 there is a Figure about a page down suggesting the decay rate falls in the time leading up to each solar flare, but then it appears to speed back up and return to the green line so that there's no long-term effect over the whole fortnight. Am I reading this incorrectly?

Thank you

 

[Drakkith]

In the article at http://physicsworld.com/cws/article/news/36108 there is a Figure about a page down suggesting the decay rate falls in the time leading up to each solar flare, but then it appears to speed back up and return to the green line so that there's no long-term effect over the whole fortnight. Am I reading this incorrectly?

Thank you

Hrmm. From the picture on the site I'm seeing multiple spikes of x-rays at the same time that the decay is slightly above average. Honestly it just looks like coincidence to me, just looking at the graph that is.

 

[Subluminal]

Hrmm. From the picture on the site I'm seeing multiple spikes of x-rays at the same time that the decay is slightly above average. Honestly it just looks like coincidence to me, just looking at the graph that is.

You're right, I had it backwards. The decay rate appears to INCREASE before and during the x-ray spikes associated with the eruptions. What does it mean when the dip returns to the straight trend line on the chart? Did the decay rate then slow down more than usual in the aftermath of the flares and then inflect back to normal, so that overall decay was as expected?

More authoritative sources suspect systematic effects. I take this to possibly mean measurement error due to an interaction between the device measuring the decay and some lurking variable that correlates to a lead up to a solar flare. Still, without inventing new physics to explain the rate increase (and to also explain the subsequent decrease?), there's potential value if such systemic effect of unknown solar radiation on that device can be improved to serve as a solar flare forecaster with a decent confidence interval. Or maybe there are new physics at work, since standard theory says neutrinos or other known causes won't affect both alpha and beta decay.

It's been 4.5 years since this was noticed with little published since (other than by Ephraim Fischbach, one of the investigators who recorded the data in the subject figure), save a study or two on other isotopes that found insufficient evidence to support or reject. Was it all just coincidence after all?

 

[bcrowell]

FAQ: Do rates of nuclear decay depend on environmental factors?

There is one environmental effect that has been scientifically well established for a long time. In the process of electron capture, a proton in the nucleus combines with an inner-shell electron to produce a neutron and a neutrino. This effect does depend on the electronic environment, and in particular, the process cannot happen if the atom is completely ionized.

Other claims of environmental effects on decay rates are crank science, often quoted by creationists in their attempts to discredit evolutionary and geological time scales.

He et al. (He 2007) claim to have detected a change in rates of beta decay of as much as 11% when samples are rotated in a centrifuge, and say that the effect varies asymmetrically with clockwise and counterclockwise rotation. He believes that there is a mysterious energy field that has both biological and nuclear effects, and that it relates to circadian rhythms. The nuclear effects were not observed when the experimental conditions were reproduced by Ding et al.

Jenkins and Fischbach (2008) claim to have observed effects on alpha decay rates at the 10^-3 level, correlated with an influence from the sun. They proposed that their results could be tested more dramatically by looking for changes in the rate of alpha decay in radioisotope thermoelectric generators aboard space probes. Such an effect turned out not to exist (Cooper 2009). Undeterred by their theory's failure to pass their own proposed test, they have gone on to publish even kookier ideas, such as a neutrino-mediated effect from solar flares, even though solar flares are a surface phenomenon, whereas neutrinos come from the sun's core. An independent study found no such link between flares and decay rates (Parkhomov 2010). Jenkins and Fischbach's latest claims, in 2010, are based on experiments done decades ago by other people, so that Jenkins and Fischbach have no first-hand way of investigating possible sources of systematic error. Laboratory experiments[Lindstrom 2010] have also placed limits on the sensitivity of radioactive decay to neutron flux that rule out a neutrino-mediated effect at a level orders of magnitude less than what would be required in order to explain the variations claimed in [Jenkins 2008].

Cardone et al. claim to have observed variations in the rate of alpha decay of thorium induced by 20 kHz ultrasound, and claim that this alpha decay occurs without the emission of gamma rays. Ericsson et al. have pointed out multiple severe problems with Cardone's experiments.

He YuJian et al., Science China 50 (2007) 170.

YouQian Ding et al., Science China 52 (2009) 690.

Jenkins and Fischbach (2008), http://arxiv.org/abs/0808.3283v1

Jenkins and Fischbach (2009), http://arxiv.org/abs/0808.3156

Jenkins and Fischbach (2010), http://arxiv.org/abs/1007.3318

Parkhomov, http://arxiv.org/abs/1006.2295

Cooper (2009), http://arxiv.org/abs/0809.4248

Lindstrom et al. (2010), http://arxiv.org/abs/1006.5071

F. Cardone, R. Mignani, A. Petrucci, Phys. Lett. A 373 (2009) 1956

Ericsson et al., Comment on "Piezonuclear decay of thorium," Phys. Lett. A 373 (2009) 1956, http://arxiv4.library.cornell.edu/abs/0907.0623

Ericsson et al., http://arxiv.org/abs/0909.2141

 

[Drakkith]

Ah, ok. Thx bcrowell!

 

[arivero]

I am worried about some elements which are marked as "stable" in the listings but whose energy balance under alpha is exothermic; the difference of masses (original)-(product+helium4) is positive. An example is the alchemical Hg 201, (I call it "alchemical" because would transmute to gold after the initial alpha to Pt and then a well known beta) but you can also find examples in Thorium and other close elements in the 150-200 range of atomic weight.

 

[Creator]

The surprise is that alpha decay rates would be modified; beta and anti-beta decay seem more likely to have something to do with anti-neutrinos and neutrinos (via some sort of stimulated emission of radiation).

Not sure what you mean by that, Carl. You mean possible stimulated emission of betas by neutrinos.?

One of the references I saw proposed that the alpha decay rates were not modified; instead, what was being seen was an influence on the decay of the daughter products. The influenced alpha decay mentioned was Ra 226. The (>99%) decay chain is:

88 Ra 226 alpha decays to 86 Rn 222; 1,601 years

86 Rn 222 alpha decays to 84 Po 218; 3.8 days

84 Po 218 alpha decays to 82 Pb 214; 3.1 minutes

82 Pb 214 beta minus decays to 83 Bi 214; 26.8 minutes

83 Bi 214 beta minus decays to 84 Po 214; 19.9 minutes

84 Po 214 alpha decays to 82 Pb 210; 164 microseconds

82 Pb 210 beta minus decays to 83 Bi 210; 22.3 years

83 Bi 210 alpha decays to 81 Tl 206; 3 million years

81 Tl 206 beta minus decays to 82 Pb 206; 4.2 minutes

82 Pb 206 is stable

In the above chain, 82 Pb 210 with a half-life of 22.3 years would tend to build up as all the isotopes higher up the decay chain have much much shorter half lives. So as a pure sample of Ra 226 ages (google "secular equilibrium"), it will build up 82 Pb 210 which decays by beta minus with a half life long enough to see a yearly influence. And then 83 Bi 210, on the scale we're looking at, is essentially stable.
l[/url]

Good possible explanation the phase lag in the data, Carl.
I wonder if they have considered the possibility of cluster decay, Known to occur for Ra 226 even though it has a much lower rate, it would skip the decay chain altogether. The split is C-14 and Pb-212.

Creator

 

[CarlB]

Not sure what you mean by that, Carl. You mean possible stimulated emission of betas by neutrinos.?

That's what I was thinking. The alpha emission is too complicated for my brain to fold around. So therefore I don't see how it would be influenced by the sun (not that I have a lot of influence on what Nature chooses to do).

 

[Creator]

That's what I was thinking. ...).

Care to share the details.

How would that work for Mn 54? How about stimulated emission of neutrinos by neutrinos... forwarding the process of inverse beta decay?

I was greatly disappointed that this proceedure a few months ago at the 'mouth' of a reactor failed to definitively determine if neutrinos could affect the Mn-54 rates since it used Anti-neutrinos, and no Ra 226... (leaving open the possibility that Jenkins (and your (or my) speculation could still work. ...he, he. )

http://www.ncbi.nlm.nih.gov/pubmed/20727777

Note the last sentence in the abstract.

So how about we test a high flux neutrino source and settle this thing?
;;..