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.
118501629
Neutrino-nucleus reactions via neutral and charged currents by the quasi-particle random phase approximation (QRPA)
We developed the quasi-particle random phase approximation (QRPA) for neutrino reactions on even–even nuclei via neutral current (NC) and charged current (CC). The QRPA has been successfully applied for nuclear β and ββ decays. To describe neutrino–nucleus reactions, general multipole transitions by the weak interaction with finite momentum transfers are calculated for NC and CC reactions with detailed formulas. Since we consider neutron–proton (np) pairing as well as neutron–neutron (nn) and proton–proton (pp) pairing correlations, the nn + pp QRPA and the np QRPA are combined in a framework, which enables us to describe both NC and CC reactions in a consistent way. Numerical results for ν–12C, –56Fe and –56Ni reactions are shown to match with other theoretical calculations and well reproduce available experimental data.
119116368
Signals for Strange Quark Contributions to the Neutrino (Antineutrino) Scattering in Quasi-Elastic Region
Strange quark contributions to elastic neutrino–nucleon scattering and neutrino–nucleus scattering for 12 C target in quasi-elastic region are investigated on the incident energy of 500 MeV within the framework of a relativistic single particle model. For the neutrino–nucleus scattering, the effects of final state interaction for the knocked-out nucleon are included by a relativistic optical potential. In the cross sections for neutrino–nucleus scattering we found some cancellations of the strange quark contributions in the knocked-out proton and neutron process. Consequently, the asymmetries between the incident neutrino and antineutrino, which are given by the ratio of neutral current to charged current, and a difference between the asymmetries are shown to be more feasible quantities for the strangeness effects. In order to explicitly display the importance of such cancellations, results of the exclusive reaction 16 O(ν, ν' p ) are additionally presented for detecting the strangeness effects.
121469003
ONE- AND TWO-STEP PROCESSES ON THE NEUTRINO-NUCLEUS SCATTERING NEAR NUCLEON THRESHOLD REGION
Neutrino (antineutrino) scattering off 12C is one of key reactions for the ν-process in the nucleosysnthesis of light nuclei, which usually assumes indirect two-step processes within the energy range from a few to tens of MeV. We investigate the direct quasi-elastic scattering off 12C around the energy region liberating one nucleon and evaluate effects of the direct processes in the abundances. The direct processes might be comparable to the indirect processes if the final state interactions between outgoing nucleons and residual nuclei are explicitly taken into account.
121377058
Final state interaction and Coulomb effect for neutrino‐nucleus scattering in the quasielastic region
We study the effect of final state interaction between outgoing nucleons and residual nuclei through total cross sections of neutrino‐nucleus scattering within the framework of a relativistic single‐particle model in the quasielastic region. To investigate the effect of the FSI, a relativistic phenomenological optical potential and a real potential for final nucleons are used. The real potential refers to no loss of flux while the optical potential indicates an absorption. We calculate both neutral‐current reaction such as (v, v′) and charged‐current reactions like (ve, e−) and (vμ, μ−). In these calculations, 12C is used as a target nucleus and the incident neutrino (antineutrino) energies are exploited up to 2 GeV. We find that the effect of the FSI by the optical potential reduces cross sections about 50% and about 15% for the real potential. Furthermore, in the case of the charged‐current reaction, we also calculate the Coulomb distortion of the outgoing leptons for 12C, 40Ca, and 208Pb. As a conseque...
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.