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We formulate a theoretical approach to describe photon vortex production in synchrotron/cyclotron radiation from a helical moving electron under a uniform magnetic field in the relativistic quantum framework. In quantum theory, electron orbitals in a magnetic field are under Landau states. The Landau level density increases with decreasing the magnetic field strength, and it is practically impossible to calculate exactly the synchrotron radiation in possible magnetic fields in the laboratory. We present a method to calculate it by using asymptotic formulations of the emission amplitudes under the condition of L_{i}−L_{f}≪L_{i}, where L_{i} and L_{f} are the initial and final Landau numbers, respectively. The wave function of the generated photon is the eigenstate of the z component of the total angular momentum (zTAM) when the magnetic field is parallel to the z axis. The approximation is applicable for photon vortex production of several tens ℏ of zTAM. We also calculate numerically the energy spectra and spatial distribution of photon vortices in magnetic field strengths of 10 and 20 T using electrons with energies of 150 MeV and 8 GeV and Larmor radii of 10 and 100 µm for the helical motion. Although the Landau number becomes up to 10^{8} in these conditions, the radiations could be calculated using the approximation. The results indicate that it is possible to produce predominantly photon vortices with a fixed zTAM when we control the energy and entrance trajectory of electrons and the structure of a magnetic field. The present formula contributes to the prediction and verification of photon vortex generation.

Ground states of even-even Ge isotopes with mass number A = 64-76 have been studied in the deformed Bardeen-Cooper-Schrieffer (BCS) theory by taking neutron-proton (np) pairing correlations as well as neutron-neutron (nn) and proton-proton (pp) pairing correlations. The np pairing has two different modes J = 0, T = 1 (isotriplet) and J = 1, T = 0 (isosinglet). In this work, the Brueckner G matrix, based on the CD-Bonn potential, has been exploited to reduce the ambiguity regarding nucleon-nucleon interactions inside nuclei compared to the results by a simple schematic phenomenological force. We found that the G matrix plays important roles to obtain reasonable descriptions of even-even nuclei compared to the schematic force. The np pairing strength has been shown to have a clear correlation with quadrupole deformation parameter β2 for the isotopes, and affects the smearing of the Fermi surfaces of not only N = Z nuclei but also N ≠ Z nuclei. In particular, the coexistence of the like particle (nn and pp) and the np pairing modes was found to become more salient by the G-matrix approach than by the schematic force approach. [ABSTRACT FROM AUTHOR]

We study the effects of density-dependent weak vector form factors on the inclusive neutral-current-neutrino (antineutrino)-nucleus scattering in the quasi-elastic region within the framework of a relativistic single-particle model. The density-dependent weak form factors are obtained from a quark-meson coupling model. The density-dependence effects are studied separately in protons and neutrons participating in the reactions, in each response cross section, and with regard to asymmetry. These density effects reduce the cross section at high densities and show different behavior with regard to asymmetry. Furthermore we calculate flux-averaged differential cross sections and compare them with the experimental data. [ABSTRACT FROM AUTHOR]

We study the effects of density-dependent electromagnetic, axial, and weak vector form factors on the inclusive (e,e') reaction and the charged-current neutrino-nucleus scattering in the quasi-elastic region within the framework of a relativistic single-particle model. The density-dependent form factors obtained from a quark-meson coupling model are applied into the (e,e') reaction and the neutrino-nucleus scattering via charged current. The effects of the density-dependent form factors increase the (e,e') cross sections by a few percent. However, the effects may reduce the differential cross sections up to 20% (60%) at p=1.0pO(2.0pO) for the antineutrino scattering and also reduce the cross section up to 20% (30%) at p=1.0pO(2.0pO) for the neutrino scattering around the peak positions, where the normal density is p0~0.15 fm-3. For the density of finite nuclei such as 12C, 40Ca, and 208Pb as 0.6, 0.7, and 1.0 of pO, the in-medium effects are 20% to 30%, even in the antineutrino case. Our theoretical double-differential and total cross sections are compared with the recent MiniBooNE data for 12C(µ,µ-) scattering. [ABSTRACT FROM AUTHOR]

We investigate the effect of final state interaction (FSI) on the neutrino (antineutrino) scattering via neutral current from a 12C target in the quasielastic region within the framework of a relativistic single-particle model. Three different descriptions of the FSI, which are a relativistic mean field, a complex optical potential, and its real potential, are taken into account for two incident neutrino energies of 500 MeV and 1 GeV. The effects of the FSI are studied not only on the differential cross sections but also on each longitudinal, transverse, and transverse interference cross section. We found that the FSI description may play a vital role for the estimation of those cross sections, and the FSI effects on each response cross section may differ from those on the differential cross section. However, the asymmetry between neutrino and antineutrino scattering cross sections turns out to be nearly independent of the FSI descriptions. Finally, possible FSI effects on the MiniBooNE data are studied in detail. [ABSTRACT FROM AUTHOR]

Gamow-Teller (GT) strength distributions of Mg isotopes are investigated within a framework of the deformed quasiparticle random-phase approximation. We found that the N = 20 shell closure in 28~34Mg was broken by the prolate shape deformation originating from the fp-intruder states. The shell closure breaking gives rise to a shift of low-lying GT excited states into high-lying states. Discussions regarding the shell evolution trend of single-particle states around N = 20 nuclei are also presented with the comparison to other approaches. [ABSTRACT FROM AUTHOR]

Using several relativistic mean-field models (such as GM1, GM3, NL3, TM1, FSUGold, and IU-FSU) as well as the quark-meson coupling model, we calculate the particle fractions, the equation of state, the maximum mass, and radius of a neutron star within relativistic Hartree approximation. We also discuss in detail the role of nonlinear potentials involved in the mean-field models. In determining the couplings of the isoscalar, vector mesons to the octet baryons, we examine the extension of SU(6) spin-flavor symmetry to SU(3) flavor symmetry. Furthermore, we consider the strange (σ* and Φ) mesons and study how they affect the equation of state. We find that the equation of state in SU(3) symmetry can sustain a neutron star with mass of (1.8 ~ 2.1 )M⊙, even if hyperons exist inside the core. It is noticeable that the strange vector (Φ) meson and the variation of baryon substructure in matter also play important roles in supporting a massive neutron star. [ABSTRACT FROM AUTHOR]

The nucleón form factors in free space are usually thought to be modified when a nucleón is bound in a nucleus or immersed in a nuclear medium. We investigate effects of the density-dependent axial and weak-vector form factors on the electroneutrino (ve) and anti-electroneutrino (ve) reactions with incident energy Ev ≤ 80 MeV via neutral current (NC) for a nucleón in a nuclear medium or 12C. For the density-dependent form factors, we exploit the quark-meson-coupling (QMC) model, and apply them to the ve and ve induced reactions by NC. About 12% decrease of the total cross section by the ve reaction on the nucleón is obtained at normal density, ρ = ρ0 ~ 0.15 fm-3, as well as about 18% reduction of the total ve cross section on 12C, by the modification of the weak form factors of the bound nucleón. However, similarly to the charged current reaction, effects of the nucleón property change in the ve reaction reduce significantly the cross sections about 30% for the nucleón in matter and 12C cases. Such a large asymmetry in the ve cross sections is addressed to originate from the different helicities of ve and ve. [ABSTRACT FROM AUTHOR]

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 (?μ,μ-) and (vμ,μ+) reactions. In these calculations, 12C, 40Ca, and 208Pb 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. [ABSTRACT FROM AUTHOR]

We calculated neutrino reactions on 40Ar for detecting core-collapsing supernovae (SNe) neutrinos. The nucleus was originally exploited to identify the solar neutrino emitted from 8B produced in pp chains on the Sun. With the higher energy neutrinos emitted from the core-collapsing SNe, contributions from higher multipole transitions, as well as from the Gamow-Teller and Fermi transitions, are shown to be important ingredients for understanding reactions induced by the SN neutrino. Moreover, higher excited states beyond a few states known in experiment diminish significantly the expected large difference between the cross sections of νe and νe reactions on 40Ar, which difference is anticipated because of the large Q value in the νe reaction. The reduction is shown to lead to a difference between them of only a factor of 2. [ABSTRACT FROM AUTHOR]

We perform systematic calculations regarding the effects by Coulomb and/or spin-orbit (SO) interaction on like- and unlike-pairing correlations in sd-, pf-, and sdgh-shell N=Z nuclei. The former two interactions are comprised in a deformed mean-field potential and the latter pairing correlations are treated by residual interactions in the mean field. We make use of two different pairing matrix elements (PMEs) for the residual interactions : constant and state-dependent Brueckner G matrix. The constant PME may give rise to meaningful information on the pairing correlations under the Wigner spin-isospin SU(4) symmetry in the absence of the Coulomb and the SO interaction. The state-dependent Brueckner PME takes into account the nuclear medium effect based on a realistic nucleon-nucleon interaction. In this work, through the analyses of the Coulomb and the SO interaction effects on the pairing correlations, we discuss in detail the isoscalar pair condensation and the coexistence of the isoscalar and the isovector pairs in the unlike pairing of the N=Z nuclei. Our results show that the Coulomb and the SO interaction as well as nuclear deformation affect the single-particle state evolution in a deformed mean field and, as a result, give significant impacts on the pairing correlations and the smearing of occupation probabilities near Fermi energy. In particular, the pairing gaps in the heavy nuclei are largely disturbed by the Coulomb interaction as well as the SO interaction. [ABSTRACT FROM AUTHOR]

We investigated neutron-proton pairing correlations effects on the shell evolution of ground-state energies by the deformation for N=Z nuclei in pf shell, such as 44Ti, 48Cr, 52Fe, 64Ge, 68Se, 72Kr, and 76Sr. We started from a simple shell-filling model constructed by a deformed Woods-Saxon potential with β2 deformation, and included pairing correlations in the residual interaction, which give rise to smearing of the Fermi surface revealing interesting evolution of the Fermi energy along the shell evolution. In this work, like-pairing and unlike-pairing correlations decomposed as isovector T=1 and isoscalar T=0 components are explicitly taken into account. Finally, we estimate ground-state energies comprising the mean-field energy, the pairing energy, and the self-energy due to the pairing correlations, in terms of the deformation. The enhanced T=0 pairing interaction supports oblate deformations for 72Kr and 68Se, whose features are different from other pf-shell N=Z nuclei considered in this work. [ABSTRACT FROM AUTHOR]

We study the shape evolution of N=Z nuclei 24Mg,28Si, and 32S in the axially symmetric deformed Woods-Saxon model, taking into account both T=0 and T=1 pairing interactions. We find the coexistence of T=0 and T=1 superfluidity phases in the large deformation region |β2|>0.3 in these three nuclei. The interplay between the two pairing interactions has an important effect on determining the deformation of the ground states in these nuclei. The self-energy contributions from the pairing correlations to the single particle (s.p.) energies are also examined. [ABSTRACT FROM AUTHOR]

We investigate effects of neutron-proton (np) pairing correlations on the Gamow-Teller (GT) transition of 24,26Mg by explicitly taking into account deformation effects. Our calculation is performed by a deformed quasiparticle random phase approximation (DQRPA) which includes the deformation at the Bardeen-Cooper-Schrieffer and RPA stage. In this paper, we include the np pairing as well as neutron-neutron (nn) and proton-proton (pp) paring correlations to the DQRPA. Our new formalism is applied to the GT transition of well-known deformed Mg isotopes. The np pairing effect is found to affect more or less the GT distribution of 24Mg and 26Mg. But the deformation effect turns out to be much larger than the np paring effect because the Fermi surfaces smear more widely by the deformation rather than the np pairing correlations. Correlations between the deformation and the np pairing effects and their ambiguities are also discussed with the comparison to experimental GT strength data by triton and ³He beams. [ABSTRACT FROM AUTHOR]

Production of a neutrino source through a proton-induced reaction is studied by using the particle transport code GEANT4. Unstable isotopes such as 27Si can be produced when the 27Al target is bombarded by 15-MeV energetic proton beams. Through the β-decay process of the unstable isotope, a new electron-neutrino source in the 0-5.0 MeV energy range is obtained. Proton-induced reactions are simulated with JENDL-4.0 High Energy File (JENDL-4.0/HE). For radioactive decay processes, we use the G4 radioactive decay model based on the Evaluated Nuclear Structure Data File (ENSDF). We suggest detailed target systems required for future solar neutrino experiments, in particular for the vacuum-matter transition region. As for a detection system of the new neutrino source, we evaluate reaction or event rates for available radiochemical detectors and Low Energy Neutrino Astronomy (LENA)-type scintillator detector and discuss effects due to possible sterile neutrinos as an application. [ABSTRACT FROM AUTHOR]

Using an optical model potential including an inelastic scattering potential as well as a conventional short-range nuclear potential, we investigate the ratio Pinel of the inelastic scattering cross section to the Rutherford cross section for the 11Be + 197Au system. As a result, we find that the contribution of the inelastic scattering to the first excited state of the 11Be projectile cannot be ignored at backward angles in unresolved elastic + inelastic scattering data and the Pinel relevant to the contribution of inelastic scattering depends on the incident energy Ec.m. and excitation energy ε. [ABSTRACT FROM AUTHOR]

We study the effects of the strange axial form factor and axial mass on both neutral- and charged-current reactions in the quasielastic region within the framework of a relativistic single-particle model. For this purpose, we calculate the differential cross section, the separated cross sections associated with the longitudinal and transverse response functions, the asymmetry for the neutral-current reaction, and the various ratios of the neutral- to charged-current reactions. The calculations are performed for a 12C target at specific incident neutrino (antineutrino) energies of 0.5 and 1.5 GeV, or with the flux-averaged incident energies of the MiniBooNE experiment. Then, we discuss the dependence of the cross sections, asymmetry, and ratios on the axial mass and strange axial form factor. Finally, we compare our calculations with the MiniBooNE experimental data. [ABSTRACT FROM AUTHOR]

For the 11Li + 208Pb system, we find that the breakup process takes place from the forward angle or far distance region through the interaction distance which is obtained from ratios of elastic scattering cross sections to the Rutherford cross section. It is well known that the behavior of the 11Li + Pb208 system is closely related to Coulomb dipole excitation effect. From the first Χ² analysis for the elastic cross section of the 9Li + 208Pb system, we obtain the short-range potential of the 11Li + 208Pb system by exploiting the optical model calculation for the Coulomb dipole excitation effect. To include the effect of the long-range interaction, we use a dynamic complex polarization potential including the Coulomb dipole potential and a long-range nuclear potential with Woods-Saxon form. Using the second Χ² analysis for the elastic cross section of the 11Li+ 208Pb system, we obtain the electric dipole transition probabilities B(E1) which becomes 1.42 e²fm² and 1.41 e²fm² at Ec.m. = 23.1 MeV and 28.3 MeV, respectively. [ABSTRACT FROM AUTHOR]

The roles of strange axial form factor and axial mass for both neutral-current and charged-current reactions are investigated in the quasi-elastic neutrino-nucleus scattering within a relativistic single-particle model. The calculation is performed for various target nuclei like 12C, 40Ca, 56Fe, and 208Pb at the incident neutrino (antineutrino) energies of 1.0 and 2.0 GeV. Then we discuss the dependence of differential cross section on the role of axial mass and strange axial form factor with different target nuclei on both neutral-current and charged-current reactions. Finally we compare our results with the MiniBooNE, T2K, and MINERνA experimental data for the double-differential cross section and the scaled total cross section. [ABSTRACT FROM AUTHOR]

The isotope 98Tc decays to 98Ru with a half-life of 4.2×106 yr and could have been present in the early Solar System. In this Letter, we report on the first calculations of the production of 98Tc by neutrino-induced reactions in core-collapse supernovae (the ν process). Our predicted 98Tc abundance at the time of solar system formation is not much lower than the current measured upper limit raising the possibility for its detection in the not too distant future. We show that, if the initial abundance were to be precisely measured, the 98Tc nuclear cosmochronometer could be used to evaluate a much more precise value of the duration time from the last core-collapse supernova to the formation of the solar system. Moreover, a unique and novel feature of the 98Tc ν-process nucleosynthesis is the large contribution (~20%) from charged current reactions with electron antineutrinos. This means that 98Tc becomes a unique new ν-process probe of the temperature of the electron antineutrinos. [ABSTRACT FROM AUTHOR]

We investigated effects of pairing correlations on the neutron skin thickness and the symmetry energy of finite nuclei. In this calculation we used Hartree-Fock-Bogoliubov method with Skyrme forces and effective pairing interactions. The results have been compared with available experimental data, Hartree-Fock results as well as the predictions by droplet model. Finally, our discussion was extended to study of the pairing interaction in nuclear matter. Roles of isospin T = 0 pairing in the nuclear matter were also discussed. [ABSTRACT FROM AUTHOR]

Within the framework of a relativistic single-particle model, we calculate inclusive electron-nucleus scattering by electromagnetic current, and neutrino-nucleus scattering by neutral and charged current in the quasi-elastic region. The longitudinal, the transverse, and the transverse-interference structure functions are extracted from the theoretical cross section by using the Rosenbluth separation method at fixed momentum transfer and scattering angle and then compared with each other from the viewpoint of these current interactions. The position of peak for the electron scattering shifts to higher energy transfer than that for the neutrino scattering. The axial and pseudoscalar terms turn out to play an important role in the neutrino-nucleus scattering. [ABSTRACT FROM AUTHOR]

We investigate ratios of the elastic scattering cross section to Rutherford cross section, PE, and angular distributions of breakup cross section by using an optical model which exploits various long-range dynamic polarization potentials as well as short-range nuclear bare potentials for the 11Be projectile. From these simultaneous analyses, we extract a large radius of a halo projectile from the experimental data for PE and the angular distribution of the breakup cross section of the 11Be+64Zn and 11Be+120Sn systems. It results from the fact that a large radius for the long-range nuclear potential is more reasonable for properly explaining these data simultaneously. The extracted reduced interaction radius turns out to be r0=3.18~3.61 fm for 11Be nucleus, which is larger than the conventional value of r0=1.1~1.5 fm used in the standard radius form R=r0A1/3. Furthermore, the larger radius as well as the normalization constant N is shown to be important for understanding Coulomb dipole strength distribution. [ABSTRACT FROM AUTHOR]

both the CDE and LRN potentials are essential to explaining the experimental values of PE, which is the ratio of the elastic scattering cross section to the Rutherford cross section. The Coulomb and nuclear parts of the LRDP potential are found to contribute to a strong absorption effect. Strong absorption occurs because the real part of the CDE and LRN potentials lowers the barrier, and the imaginary part of the CDE and LRN potentials removes the flux from the elastic channel in the 11Be + 64Zn system. Finally, we extract the total reaction cross section σR including the inelastic, breakup, and fusion cross sections. The contribution of the inelastic scattering by the first excited state εx = 0.32 MeV (l/2-) is found to be relatively large and cannot be ignored. In addition, our results are shown to agree quite well with the experimental breakup reaction cross section by using a fairly large radius parameter. [ABSTRACT FROM AUTHOR]

We estimate the maximum possible contribution to the early spin deceleration of protoneutron stars because of asymmetric neutrino absorption. We calculate the neutrino scattering in the context of a fully relativistic mean field theory and estimate for the first time the spin deceleration of neutron stars because of asymmetric neutrino absorption in a toroidal magnetic field configuration. We find that the deceleration can be much larger for asymmetric neutrino absorption in a toroidal magnetic field than the braking due to magnetic dipole radiation. Nevertheless, the effect is estimated to be less than the angular momentum loss due to the transport of magnetically locked material in the neutrino energized wind. [ABSTRACT FROM AUTHOR]

We investigate the structure of proto-neutron stars (PNSs) with trapped neutrinos by using a quark-meson coupling model. We adopt a phenomenological lepton density which is diffuse near the surface. We calculate the populations of baryons and leptons, the equations of state, and the mass-radius relation for isentropic PNS models. In addition, the moment of inertia is calculated for both PNS and cold-neutron-star (CNS) models as a means to study the change of the spin period due to the neutrino emission from a PNS. Neutrino emission from a hyperonic neutron star is shown to increase the spin by about 10% of the initial spin, while the spin of a nucleonic neutron star with a central density above ρc &ap; 5ρ0 is decreased by a few % by the emission of neutrinos. Therefore, the spin change owing to the leakage of neutrinos from a PNS is a small (<10%) correction compared to other processes related to the spin change [ABSTRACT FROM AUTHOR]

We investigate the structure of a proto-neutron star with trapped neutrinos by using quantum hadrodynamics. Ratios of the trapped neutrinos and corresponding leptons to the baryons are usually assumed to be constant. But relevant reactions associated with the β equilibrium could be sensitive to the given density and temperature. By adopting a phenomenological lepton density that is smeared near the surface, we calculate and discuss populations of baryons and leptons, equations of state, and the mass-radius relation of a proto-neutron star in an isentropic process. [ABSTRACT FROM AUTHOR]