Periodically does a measured value of Radon decay rate change, mad be the scientist who will assert influences by solar and cosmic neutrinos on beta decay...
... before having checked more mundane causes with scrutiny!
It is well-known that a radioactive substance follows a fixed exponential decay, no matter what you do to it. The fact has been set in stone since 1930 when the “father” of nuclear physics Ernest Rutherford, together with James Chadwick and Charles Ellis, concluded in their definitive Radiations from Radioactive Substances that “the rate of transformation…is a constant under all conditions.”
But this is no longer the view of a pair of physicists in the US. Ephraim Fischbach and Jere Jenkins of Purdue University in Indiana are claiming that, far from being fixed, certain decay “constants” are influenced by the Sun. It is a claim that is drawing mixed reactions from others in the physics community, not least because it implies that decades of established science is flawed.
02 Oct 2008
An analysis of 85,000 measurements of gamma radiation associated with the decay of radon and its progeny in a sealed container located in the yard of the Geological Survey of Israel (GSI) in Jerusalem, between February 15, 2007 and November 7, 2016, reveals variations in both time of day and time of year with amplitudes of 4% and 2%, respectively. The phase of maximum of the annual oscillation occurs in June, suggestive of a galactic influence. Measurements made at midnight show strong evidence of an influence of solar rotation, but measurements made at noon do not. We find several pairs of oscillations with frequencies separated by 1 year⁻¹, indicative of an influence of rotation that is oblique with respect to the normal to the ecliptic, notably a pair at approximately 12.7 year⁻¹ and 13.7 year⁻¹ that match the synodic and sidereal rotation frequencies of the solar radiative zone as determined by helioseismology.
Another notable pair (approximately 11.4 year⁻¹ and 12.4 year⁻¹ ) may correspond to an obliquely rotating inward extension of the radiative zone. [Thus these results may have implications concerning solar structure.] We also find a triplet of oscillations with approximate frequencies 7.4 year⁻¹, 8.4 year⁻¹ and 9.4 year⁻¹ which, in view of the fact that the principal oscillation in Super-Kamiokande measurements is at 9.4 year⁻¹, may have their origin in an obliquely rotating core. We propose, as a hypothesis to be tested, that neutrinos can stimulate beta decays and that, when this occurs, the secondary products of the decay tend to travel in the same direction as the stimulating neutrino. The effective cross-section of this process is estimated to be of order 10⁻¹⁸ cm². [this influence of neutrinos on radioactive material may be large enough to be open to experimental tests of force and torque as suggested in Sturrock. Fischbach, Javorsek et al...
To be cautious, one might also consider the possibility that neutrinos may stimulate alpha decays, but – to the best of our knowledge – there is no evidence of variability in nuclear processes that involve only alpha decays... Our current analysis of GSI data is restricted to measurements of gamma radiation that has its origin in beta decays, not in alpha decays. For these reasons, we here confine our hypothesis to a possible influence of neutrinos on beta decays. If future experiments yield evidence of an intrinsic variability of alpha decays, it will be necessary to revise this hypothesis.]
The striking diurnal asymmetry appears to be attributable to a geometrical asymmetry in the experiment... Night-time data show a number of curious “pulses” of duration 1 - 3 days... We have been unable to identify any similar features in any record of known solar phenomena. This raises the possibility that they may have their origin in cosmic neutrinos that have passed through or near the Sun and are traveling away from the Sun.
If the association of neutrino and beta-decay oscillations with solar rotation proves valid, one will need to understand theoretically the mechanism that leads to this association. One promising theoretical approach seems to be the Resonant Spin Flavor Precession mechanism by which neutrinos of one flavor, traveling through a plasma permeated by magnetic field, can change to a different flavor ({Voloshin 1986,} Akhmedov, 1988...)
Here is the last rebuttal by S. Pommé based on a detailed analysis of the largest amount of data
communicated to him up to now:
The instabilities in the radon measurements at the Geological Survey of Israel are obviously related with solar irradiance and rainfall and cannot be ascribed to neutrinos. Besides sensitivity of the electronics, free movement of radon gas inside the tank along temperature gradients is the most likely mechanism behind the diurnal and seasonal decay rate changes in the small gas volumes monitored by the detectors.
The observation of “neutrino-induced decay” appears to be an illusion fed by confirmation bias. The experiment has not been conducted with sufficient care to eliminate environmental influences and counter-evidence has been systematically ignored to maintain the claim of new physical discoveries. The evidence does not suggest that radioactive decay is triggered by neutrinos. The subsequently emitted radiation is not aligned with neutrino flux. There are no cyclic deviations from the exponential decay law. Ensuing inference about solar dynamics is unfounded.
Acknowledgements: The authors thank Dr. Gideon Steinitz for kindly providing the additional data set for the three counters recorded between 2007 and 2011.
S. Pommé (Received: 5 December 2018 / Accepted: 11 January 2019)
A nice review article on the different aspects of neutrino oscillations to celebrate 50 years of discoveries thanks to solar neutrinos
“If the oscillation length is large. . . from the point of view of detection possibilities an ideal object is the Sun.” This statement from Pontecorvo’s 1967 paper [1] published before release of the first Homestake experiment results [2] can be considered as the starting point for the solar neutrino studies of new physics.
Observation of the deficit of signal in the Homestake experiment was the first indication of existence of oscillations. This result had triggered vast experimental [3] and theoretical developments in neutrino physics. On theoretical side, various non-standard properties of neutrinos have been introduced and new effects in propagation of neutrinos have been proposed. These include:
1. Neutrino spin-precession in the magnetic fields of the Sun due to large magnetic moments of neutrinos [4, 5]: electromagnetic properties of neutrinos have been studied in details.
2. Neutrino decays: Among various possibilities (radiative, 3ν decay, etc.) the decay into light scalar, e.g., Majoron, is less restricted [6, 7].
3. The MSW effect: The resonance flavor conversion inside the Sun required neutrino mass splitting in the range ∆m2 = (10−7 − 10−4 ) eV2 and mixing sin2 2θ > 10−3 [8– 13]. This was the first correct estimation of the neutrino mass and mixing intervals. With adding more information three regions of ∆m2 and sin2 2θ have been identified: the so called SMA, LMA and LOW solutions.
4. “Just-so” solution: vacuum oscillations with nearly maximal mixing and oscillation length comparable with distance between the Sun and the Earth have been proposed [14].
5. Oscillations and flavor conversion due to non-standard neutrino interactions of massless neutrinos [8, 9, 15, 16].
6. Resonant spin-flavor precession [17, 18], which employs matter effect on neutrino spin precession in the magnetic fields. The effect is similar to the MSW conversion.
7. Oscillation and conversion in matter due to violation of the equivalence principle [19], Lorentz violating interactions [20], etc.
In turn, these proposals led to detailed elaboration of theory of neutrino propagation in different media as well as to model-building which explains non-standard neutrino properties.
Studies of the solar neutrinos and results of KamLAND experiment [21–23] led to establishing the LMA MSW solution as the solution of the solar neutrino problem. Other proposed effects are not realized as the main explanation of the data. Still they can be present and show up in solar neutrinos as sub-leading effects. Their searches allow us to get bounds on corresponding neutrino parameters. Thus, the Sun can be used as a source of neutrinos for exploration of non-standard neutrino properties. In this review we summarize implications of results from the solar neutrino studies for neutrino physics, the role of solar neutrinos in establishing the 3ν mixing paradigm, in searches for new physics beyond the standard model.
(Submitted on 19 Jul 2015 (v1), last revised 16 Jan 2017 (this version, v4))
