[en] We investigate the neutron polarization induced by interfering pseudo-spins between two graphene sheets inserted into a cavity with a circularly polarized photon field. We find that only when two graphene sheets are located at the coordinate positions of some anti-nodes of standing photon field, the neutron polarization is most remarkable. This is caused by an interference effect of pseudo-spins between two graphene sheets induced by photons and neutron. This neutron polarization mechanism has potential application on neutron polarization device. (author)

No abstract available

[en] We completed our analysis of experiments, some completed, some planned, and some only conceptual at present, that purport to demonstrate new kinds of non-local and topological effects in the interaction of a neutron with an external electromagnetic field. In the Aharonov-Casher effect (AC), the neutron interacts with an electric field and in the Scalar Aharonov-Bohm effect (SAB) the neutron interacts with a magnetic field. In both cases, the geometry can be arranged so that there is no force on the neutron but an interference experiment nevertheless finds a phase shift proportional to the applied field and to the neutron's magnetic moment. Previously, we showed that the accepted interpretation of these phenomena as topological effects due to a non-local interaction between the neutron and the electromagnetic field is incorrect. Both AC and SAB follow from local torques on the neutron whose expectation values vanish at every instant but which have non-vanishing effect on the measurable spin-correlation variables S(t) = (1/2) [σ_xσ_x(t) + σ_y(0)σ_y(t) + h.c.] and V(t) = [σ_x(0)σ_y(t) - σ_y(0)σ_x(t) + h.c.]. We have now completed this work by observing that a criterion often used for identifying a topological effect, energy independence of the phase shift between two arms of an interferometer, is only a necessary condition, and by describing a phase shifter which obeys the energy-independence condition but whose interaction with the neutron is neither topological nor even non-local

[en] Similar to the well-known Gamow window for charged particle induced reactions, there exists an effective energy window for photon-induced reactions. Properties of this window are discussed in detail for (γ, n) and (γ, α) reactions. These reactions are important for the nucleosynthesis of rare neutron-deficient p nuclei

[en] We present an analysis of the Beam-Target double polarization asymmetry for the photoproduction of Θ⁺ in γn→Θ⁺K^-. We show that this quantity can serve as a filter for the determination of the Θ⁺'s spin-parity assignment near threshold. It is highly selective between 1/2⁺ and 1/2^- configurations due to dynamical reasons

No abstract available

[en] We have measured (γ,p) and (γ,n) differential yields at 90 degree for the two-body photodisintegration of ⁴He using tagged photons of energy E_γ=25--60 MeV. Data for both channels were obtained simultaneously using windowless ΔE-E telescopes to detect the ³He and ³H recoils. The ration of our angle-integrated yields, which is insensitive to systematic uncertainies due to the simultaneity of the measurements, agrees with calculations employing only charge-symmetric nuclear interactions. Thus, within the present errors, our data show no evidence of a significant charge-symmetry violation in ⁴He in this energy range

[en] An overview is presented of the progress of the project, coordinated by the IAEA Nuclear Data Section, to assess the status of photon production data for applications, to improve database and calculational methods and to recommend procedures and methods for evaluation of these data. The project focuses on photons produced primarily in interactions with low-energy neutrons (< 30 MeV). (author)

No abstract available

[en] It is demonstrated that measurements of photon asymmetry in the γn→K^-K⁺n reaction, can most likely determine the parity of the newly discovered Θ⁺ pentaquark. We predict that if the parity of Θ⁺ is positive, the photon asymmetry is significantly positive; if the parity is negative, the photon asymmetry is significantly negative. If the background contribution is large, the photon asymmetry may become very small in magnitude, thereby making it difficult to distinguish between the positive and negative parity results. However, even in this case, a combined analysis of the (K⁺n) invariant mass distribution and photon asymmetry should allow a determination of the parity of Θ⁺