119204961
Ambiguities of neutrino (antineutrino) scattering on the nucleon due to the uncertainties of relevant strangeness form factors
Strange quark contributions to the neutrino (antineutrino) scattering on the nucleon level are investigated in the quasi-elastic region. Incident energy is used at 500 MeV for the scattering. All of the physical observables by the scattering are investigated within available experimental and theoretical results for strangeness form factors of the nucleon. Specifically, a newly combined datum of the parity violating electron scattering and the neutrino scattering is exploited for the strangeness form factors. Feasible quantities to be explored for the strangeness contents are discussed for the application to the neutrino–nucleus scattering.
121427481
Investigating the Suppressions for the Longitudinal Structure Function in High Energy Quasielastic Scattering from 56Fe
We investigate the cross sections for inclusive (e, e') reaction from 56 Fe in quasielastic region at large electron energies (2-4GeV) and large three momentum transfer (0.5-1.5 GeV/c). We use a relativistic mean-field single particle model for the bound and continuum nucleon wave functions based on the σ-ω model and we include the effects of electron Coulomb distortion in the calculation. The results are compared to high energy data from SLAC and more recent data from Jefferson Laboratory, particularly for the kinematics where the quasielastic process is expected to dominate the cross section with the energy transfer less than 500 to 600 MeV. The effects of the predicted weakening of the strong scalar and vector potentials of the σ-ω model at high energy are discussed. Possible evidence for "longitudinal suppression" or modifications of nucleon form factors in the medium is considered, but neither is necessary to explain the quasielastic data for four momentum transfers less than 1 (GeV/c) 2 .
121132966
ANALYSES OF THE KAON PHOTO- AND ELECTRO-PRODUCTION IN THE ISOBAR MODEL
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.
123347235
Inclusive charged-current neutrino-nucleus scattering in the quasielastic region
We study inclusive charged-current reaction through total cross sections of neutrino-nucleus scattering within the framework of a relativistic single-particle model in the quasielastic region. To describe the final-state interaction between knocked-out nucleons and the residual nucleus, a real potential of final nucleons, which is generated by a relativistic mean field, is used with the assumption of no loss of flux, which leads to current conservation and gauge invariance. We calculate ({nu}{sub {mu},{mu}}{sup -}) and ({nu}-bar{sub {mu},{mu}}{sup +}) reactions. In these calculations, {sup 12}C, {sup 40}Ca, and {sup 208}Pb are used as target nuclei and the incident neutrino (antineutrino) energies are exploited up to 4 GeV. We find that the effect of the final-state interaction by the real potential of the knocked-out nucleons reduces cross sections by about 15%, similar to the effect of electron scattering. Furthermore, the effect of the Coulomb distortion for the outgoing leptons is shown to be different from the electron scattering. Finally, our total cross sections by scaling number of participated nucleons are presented to compare with experimental data.
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.
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.
17742099
Cosmic-ray tests for quality control of the CDF plug upgrade EM calorimeter and the CDF plug preshower detector
The CDF Plug Upgrade electromagnetic (EM) calorimeter and the preshower detector consist of tile-"ber elements forming a projective tower geometry. Each of the 23 longitudinal layers is separated into 24 units in the azimuthal direction. Cosmic-ray tests as a quality control of these mechanically basic units, called the 153 units, were carried out since January 1995 and completed in June 1996. All the units amounting to a total 1200 units were processed. By using HAMAMASU R4125 for the photon readout, the average light yields were measured to be 5.8 and 21 photoelectrons for the EM and the preshower units, respectively. The light yield variation along the longitudinal layers of EM tower was measured to be 10%. A GEANT-simulation study using the results of the cosmic-ray tests was performed for a realistic calorimeter con"guration. It was found that the simulated energy resolution was consistent with the requirement of *E/E"J(16%)2/E#(1%)2 (E in GeV). Adding preshower response to EM response improved in particular the linearity of the calorimeter. It was possible to achieve the non-linearity of 1% level for energies in the range of 10}200 GeV. ( 2000 Elsevier Science B.V. All rights reserved.