118015801
Strange quark contributions to neutrino and antineutrino nucleus scattering via neutral current in quasi-elastic region
Strange quark contributions to the neutral current reaction in the neutrino scattering are investigated on the nucleon level and extended to the $^{12}$C target nucleus through the neutrino-induced knocked-out nucleon process in the quasi-elastic region within the framework of a relativistic single particle model. The incident energy range between 500 MeV and 1.0 GeV is used for the neutrino(antineutrino) scattering. Effects of the final state interaction for the knocked-out nucleon are included by a relativistic optical potential. We found that the sensitivity of the strange quark contents could be salient on the asymmetry between neutrino and antineutrino scattering cross sections. In specific, $A (\nu ({\bar \nu}), \nu^{'} ({\bar \nu}^{'}) N)$ reaction is shown to be very sensitive test in the searches of the strangeness.
189904802
Parity Violation in Electron Quasi-Elastic Scattering
Parity violating electron scattering on a nucleus in the quasi-elastic region is investigated within a relativistic single particle model from 208Pb and with the incident electron energy up to 1 GeV. We discuss the effect of nucleon electromagnetic form factors by comparing the standard Sachs form factors with the parameterized form recently adjusted to the world data. The effect of the strangeness is also investigated through the recent results of the strangeness form factors, and we separately calculate the asymmetries of longitudinal and transverse response functions.
37323655
Coulomb sum rule in the quasielastic region
Within a relativistic single particle model, we calculate the Coulomb sum rule of inclusive electron scattering from {sup 40}Ca and {sup 208}Pb in the quasielastic region. Theoretical longitudinal and transverse structure functions are extracted for three-momentum transfers from 300 to 500 MeV/c and compared with the experimental data measured at Bates and Saclay. We find that there is no drastic suppression of the longitudinal structure function and that the Coulomb sum rule depends on the nucleus in our theoretical model.
116255134
Roles of Direct Break-up Reaction on Neutrino Scattering off $^{12}$C near Nucleon Threshold Region
Neutrino (antineutrino) scattering off $^{12}$C is one of various important key reactions for $\nu$-process in the nucleosysnthesis of light nuclei. Most of neutrino-nucleus scattering are considered through indirect processes within the energy range from a few to tens of MeV. Target nuclei are excited by incident neutrino (antineutrino) through various transitions, and subsequently decay into other nuclei with emitting particles. But, direct processes are also feasible, in which incident neutrino (antineutrino) strips directly one nucleon from target nuclei. Consequently, direct processes may affect abundances of $^{11}$C and $^{11}$B additionally to indirect processes. We investigate direct neutrino (antineutrino) quasi-elastic scattering off $^{12}$C around the energy region liberating one nucleon and discuss implications of direct processes in the nucleosynthesis. The direct processes might be comparable to the indirect processes if the final state interaction is taken into account.
121016358
Lifetime of a Nuclear Excited State in Cascade Decay
It is shown that the lifetime of a nuclear excited state in the region of femtoseconds could be accurately measured by a precision measurement facility of a flat crystal spectrometer, if the angular correlation of two successive γ-rays in cascade decay is taken into account in the Doppler shift attenuation method.
122428021
ANALYSIS OF PION WEAK-PRODUCTION NEAR THRESHOLD BY MULTIPOLE AMPLITUDES
By exploiting the chiral Ward identities based on the QCD Lagrangian for pion weak production, we derive a transition amplitude by the weak current and show analytical results of relevant multipole amplitudes without any expansion. Their physical implications and numerical results are also discussed.
118406337
Coherent/incoherent metal transition in a holographic model
A bstractWe study AC electric (σ), thermoelectric (α), and thermal κ¯$$ \left(\overline{\kappa}\right) $$ conductivities in a holographic model, which is based on 3+1 dimensional Einstein-Maxwell-scalar action. There is momentum relaxation due to massless scalar fields linear to spatial coordinate. The model has three field theory parameters: temperature (T), chemical potential (μ), and effective impurity (β). At low frequencies, if β < μ, all three AC conductivities (σ, α,κ¯$$ \overline{\kappa} $$) exhibit a Drude peak modified by pair creation contribution (coherent metal). The parameters of this modified Drude peak are obtained analytically. In particular, if β ≪ μ the relaxation time of electric conductivity approaches to 23μ/β2$$ 2\sqrt{3\mu }/{\beta}^2 $$ and the modified Drude peak becomes a standard Drude peak. If β > μ the shape of peak deviates from the Drude form (incoherent metal). At intermediate frequencies (T < ω < μ), we have analysed numerical data of three conductivities (σ, α,κ¯$$ \overline{\kappa} $$) for a wide variety of parameters, searching for scaling laws, which are expected from either experimental results on cuprates superconductors or some holographic models. In the model we study, we find no clear signs of scaling behaviour.