We discuss the possibility of forecasting earthquakes by means of (anti)neutrino tomography. Antineutrinos emitted from reactors are used as a probe. As the antineutrinos traverse through a region prone to earthquakes, observable variations in the matter effect on the antineutrino oscillation would provide a tomography of the vicinity of the region. In this preliminary work, we adopt a simplified model for the geometrical profile and matter density in a fault zone. We calculate the survival probability of electron antineutrinos for cases without and with an anomalous accumulation of electrons which can be considered as a clear signal of the coming earthquake, at the geological region with a fault zone, and find that the variation may reach as much as 3% for νe emitted from a reactor. The case for a νe beam from a neutrino factory is also investigated, and it is noted that, because of the typically high energy associated with such neutrinos, the oscillation length is too large and the resultant variation is not practically observable. Our conclusion is that with the present reactor facilities and detection techniques, it is still a difficult task to make an earthquake forecast using such a scheme, though it seems to be possible from a theoretical point of view while ignoring some uncertainties. However, with the development of the geology, especially the knowledge about the fault zone, and with the improvement of the detection techniques, etc., there is hope that a medium-term earthquake forecast would be feasible. PACS numbers: 14.60.Pq, 13.15.+g 91.30.Px 91.35.Pn

In this work, we derive the nuclear form factor for the spin-independent collision between the WIMPs and nucleus in terms of the relativistic mean field (RMF) theory. Comparison with the traditional form factors which are commonly used in literature is given and it is found that our results are slightly above that of the 2PF model by 4% to 8%, but deviate from the Helm form factor by 15% to 25% for the whole recoil energy spectrum of 0∼ 100 keV. Moreover, taking Xe and Ge as examples, we show the dependence of the form factor on the recoil energy.

For direct dark matter detections, to extract useful information about the fundamental interaction from data, it is crucial to properly determine the nuclear form factor. The form factor for spinindependent cross section of collisions between dark matter particle and nucleus is thoroughly studied by many authors. When the analysis was carried out, the nuclei are always supposed to be spherically symmetric. In this work, we investigate the effects of deformation of nuclei from a spherical shape to an elliptical shape on the form factor. Our results indicate that as long as the ellipticity is not too large, such effects cannot cause any substantial effects, especially as the nuclei are randomly orientated in a room temperature circumstance one can completely neglect them.

In the whole Letter, 𝐽/𝜓 should be replaced by 𝜓(2𝑆). On the page 071301-3, in the fifth paragraph "ℬℛ(𝐽/𝜓 → Λ 𝑐 +Σ + ) = 1.90×10 −10 " should be "ℬℛ(𝜓(2𝑆) → Λ 𝑐 + Σ + ) = 2.87 × 10 −10 " and " ℬℛ(𝐽/𝜓 → Λ 𝑐 + 𝑝) as 1.77 × 10 −11 " should be "ℬℛ(𝜓(2𝑆) → Λ 𝑐 + 𝑝) as 2.68 × 10 −11 ".On the page 071301-3, in the sixth paragraph "ℬℛ(𝐽/𝜓 → Λ 𝑐 + Σ + ) to be 3.57 × 10 −25 for the scalar unparticle" should be "ℬℛ(𝜓(2𝑆) → Λ 𝑐 + Σ + ) to be 5.35 × 10 −25 for the scalar unparticle" and "1.59 × 10 −19 for the vector unparticle" should be "2.40 × 10 −19 for the vector unparticle".