Limits on the Neutrino Magnetic Moment using 1496 Days of Super-Kamiokande-I Solar Neutrino Data (original) (raw)
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Journal of Physics G: Nuclear and Particle Physics, 2004
A global analysis of the solar neutrino data from all solar neutrino experiments combined with the KamLAND data is presented assuming that the solar neutrino deficit is due to the matter-enhanced spin-flavor precession effect. We used two types of magnetic field profiles throughout the entire Sun: Wood-Saxon shape and the Gaussian shape. We showed that for Dirac neutrinos, the allowed regions are independent of the magnetic field profiles for all of the magnetic moments that we used in this paper and the allowed region in the large mixing angle (LMA) region shifted to the small mixing angle (SMA) region as µB value is increased. We calculated the allowed regions at 95% CL. We also find a limit for the electron neutrino magnetic moment at 0.95CL so that µB < 0.2 × 10 −7 µ B G for both magnetic field profiles at 1σlevel.
We present here a recopilation of recent results about the possibility of detecting solar electron antineutrinos produced by solar core and convective magnetic fields. These antineutrinos are predicted by spin-flavor oscillations at a significant rate even if this mechanism is not the leading solution to the SNP. Using the recent Kamland results and assuming a concrete model for antineutrino production by spin-flavor precession in the convective zone based on chaotic magnetic fields,we obtain bounds on the flux of solar antineutrinos, on the average conversion neutrino-antineutrino probability and on intrinsic neutrino magnetic moment. In the most conservative case, mulsim2.5times10−11muB\mu\lsim 2.5\times 10^{-11} \mu_Bmulsim2.5times10−11muB (95% CL). When studying the effects of a core magnetic field, we find in the weak limit a scaling of the antineutrino probability with respect to the magnetic field profile in the sense that the same probability function can be reproduced by any profile with a suitable peak field value...
Constraining the Neutrino Magnetic Moment with Antineutrinos from the Sun
Physical Review Letters, 2004
We discuss the impact of different solar neutrino data on the spin-flavor-precession (SFP) mechanism of neutrino conversion. We find that, although detailed solar rates and spectra allow the SFP solution as a sub-leading effect, the recent KamLAND constraint on the solar antineutrino flux places stronger constraints to this mechanism. Moreover, we show that for the case of random magnetic fields inside the Sun, one obtains a more stringent constraint on the neutrino magnetic moment down to the level of µν < ∼ few × 10 −12 µB, similar to bounds obtained from star cooling. PACS numbers: 26.65.+t Solar neutrinos 96.60.Jw Solar interior 13.15.+g Neutrino interactions 14.60.Pq Neutrino mass and mixing
Effect of neutrino magnetic moment on solar neutrino observations
Astrophysics and Space Science, 1971
Neutrino spin precession effects in the magnetic field of the Sun are considered as an explanation of the outcome of Davis' solar neutrino experiments. Theoretical/y, it is possible to account for a neutrino magnetic moment only as the result of the interaction of the electromagnetic field with charged particles into which the neutrino can transform virtually. The currently accepted theory of weak interactions (the two component neutrino and V-A interactions) forbids a resulting magnetic moment interaction with the electromagnetic field for all such virtual processes. Modifications of this theory are considered to find out whether an appreciable precession effect is permitted within the experimentally established limits. It is found that the value for the neutrino magnetic moment evaluated under these theoretically anomalous circumstances is still so small that only the largest possible estimate for the magnetic field strength in the Sun's interior would cause the required effect.
Neutrino Dipole Moments and Solar Experiments
2009
First we investigate the possibility of detecting solar antineutrinos with the KamLAND experiment. Then we analyze the first Borexino data release to constrain the neutrino magnetic moment. Finally we investigate the resonant spin flavour conversion of solar neutrinos to sterile ones, a mechanism which is added to the well known LMA one. In this last condition, we show that the data from all solar neutrino experiments except Borexino exhibit a clear preference for a sizable magnetic field. We argue that the solar neutrino experiments are capable of tracing the possible modulation of the solar magnetic field. In this way Borexino alone may play an essential role although experimental redundancy from other experiments will be most important.
Neutrino Oscillations, Solar Antineutrinos and the Solar Magnetic Fields
2003
Even after the confirmation of the large mixing angle (LMA) solution of the solar neutrino problem, the scope for resonant spin- flavor precession (RSFP) transitions as a subdominant effect still exists. In this work,we have considered suitably suppressed RSFP transitions in addition to the dominant LMA flavor transitions and translated the bounds on the antineutrino flux into the bounds on
Bounds and Implications of Neutrino Magnetic Moments from Atmospheric Neutrino Data
1999
The neutral current effects of the future high statistics atmospheric neutrino data can be used to distinguish the mechanisms between a ν_μ oscillation to a tau neutrino or to a sterile neutrino. However, if neutrinos possess large diagonal and/or transition magnetic moments, the neutrino magnetic moments can contribute to the neutral current effects which can be studied by the single π^0 production events in the Super-K data. This effect should be included in the future analyses of atmospheric data in the determination of ν_μ to tau or sterile neutrino oscillation.