124647709
Systematic study of the symmetry energy under the local density approximation
The nuclear matter symmetry energy ${C}_{\mathrm{sym}}(\ensuremath{\rho})$ and its slope parameter $L$ are studied using local density approximation. With this method, the symmetry energy of nuclear matter can be deduced from matter density distributions of finite nuclei. By systematically analyzing the extracted $L$ for different isotopes, the variation trends of values of extracted $L$ along isotopic chains can be obtained. The study can explain why the neutron rich nuclei in isotopic chains such as ${}^{208}$Pb can be used to extract $L$ under local density approximation. By studying the regularity of extracted $L$ for different isotopic chains, we finally obtain the value of $L$ and its error bar: $L=66\ifmmode\pm\else\textpm\fi{}7$ MeV. Besides, the density dependence parameter $\ensuremath{\gamma}$ is constrained to be $0.69\ifmmode\pm\else\textpm\fi{}0.07$ for the ansatz of symmetry energy ${C}_{\mathrm{sym}}(\ensuremath{\rho})={C}_{\mathrm{sym}}({\ensuremath{\rho}}_{0}){(\frac{\ensuremath{\rho}}{{\ensuremath{\rho}}_{0}})}^{\ensuremath{\gamma}}$.
121943751
Theoretical study of nuclear charge densities with elastic electron scattering
The calculated cross sections for elastic Coulomb electron scattering from the phase-shift analysis method and the eikonal approximation are compared. It is shown that the phase-shift analysis method can reproduce the experimental data very well for both light and heavy nuclei. Then the phase-shift analysis is used to investigate elastic electron scattering along the O and S isotopic chains, where the charge densities are obtained from relativistic mean-field theory. Results show that the minima of the differential cross section shift inward and upward with the increase of the neutron number.
121588345
Coupled-channels study of fine structure in the {alpha} decay of well deformed nuclei
We formulate a theoretical model for the {alpha} decay of well-deformed even-even nuclei based on the coupled-channel Schroedinger equation. The {alpha}-decay half-lives and fine structures observed in {alpha} decay are well described by the five-channel microscopic calculations. Since the branching ratios to high-spin states are hard to understand in the traditional {alpha}-decay theories, this success could be important to interpret future observations of heavier nuclei. It is also found that the {alpha} transition to high-spin states is a powerful tool to probe the energy spectrum and deformation of daughter nuclei.
122795101
Relativistic eikonal approaches to parity violating electron-nucleus scattering
The Coulomb electron scattering on even-even nuclei and the magnetic electron scattering on odd-$A$ nuclei have been investigated in the relativistic eikonal approximation and in the plane wave Born approximation, respectively. In this article, we generalize the relativistic eikonal approximation to the parity violating electron scattering on even-even nuclei. The parity violating asymmetries at electron energy of 850 MeV are calculated for three typical cases: Ca isotopes, $N=50$ isotones, and $N=Z$ doubly magic nuclei. In calculations the proton and neutron densities are obtained from the relativistic mean-field theory. The parity violating asymmetries are analyzed by comparing both the form factors and the densities of neutrons and protons. It is found that the parity violating asymmetries are sensitive to the differences between neutron and proton densities. Our results provide useful references for the parity violating electron-nucleus scattering experiments in the future.
126298012
New Geiger-Nuttall law for alpha decay of heavy nuclei
119699060
β-decay half-lives including first-forbidden contributions for neutron-rich Zn isotopes in the extended QRPA with neutron-proton pairing
The β decays of neutron-rich Zn isotopes are investigated within the extended quasiparticle random-phase approximation, where neutron-neutron, proton-proton, and neutron-proton pairing correlations are considered in the similar manner. The Bruckner G-matrix obtained with the charge-dependent Bonn nucleon-nucleon force is used for the residual particle-particle and particle-hole interactions in addition to the pairing interactions. Contributions from both allowed Gamow-Teller and first-forbidden transitions are considered, and β-decay half-lives together with β-delayed neutron emission probabilities are calculated. The calculated results are found to agree well with the available experimental data.
3955280
Combination and QCD analysis of charm production cross section measurements in deep-inelastic ep scattering at HERA
Measurements of open charm production cross sections in deep-inelastic ep scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections $\sigma_{\rm red}^{c\bar{c}}$ for charm production are obtained in the kinematic range of photon virtuality 2.5≤Q2≤2000 GeV2 and Bjorken scaling variable 3⋅10−5≤x≤5⋅10−2. The combination method accounts for the correlations of the systematic uncertainties among the different data sets. The combined charm data together with the combined inclusive deep-inelastic scattering cross sections from HERA are used as input for a detailed NLO QCD analysis to study the influence of different heavy flavour schemes on the parton distribution functions. The optimal values of the charm mass as a parameter in these different schemes are obtained. The implications on the NLO predictions for W± and Z production cross sections at the LHC are investigated. Using the fixed flavour number scheme, the running mass of the charm quark is determined.
7776635
Measurements of the continuum R(uds) and R values in e(+)e(-) annihilation in the energy region between 3.650 and 3.872 GeV.
We report measurements of the continuum R(uds) near the center-of-mass energy of 3.70 GeV, the R[uds(c)+psi(3770)](s) and the R(had)(s) values in e(+)e(-) annihilation at 68 energy points in the energy region between 3.650 and 3.872 GeV with the BES-II detector at the BEPC Collider. We obtain the R(uds) for the continuum light hadron (containing u, d, and s quarks) production near the DD threshold to be R(uds)=2.141+/-0.025+/-0.085.
209869998
Observation of the decay psi(2S) ---> K*(892)anti-K + c.c.
115206076
Search for strange pentaquark resonances with ZEUS at HERA
122743677
Multijet production in neutral current deep inelastic scattering at HERA and determination of alpha(s)
Multijet production rates in neutral current deep inelastic scattering have been measured in the range of exchanged boson virtualities 10 5 GeV and -1 < η LAB jet < 2.5. Next-to-leading-order QCD calculations describe the data well. The value of the strong coupling constant α s (M Z ), determined from the ratio of the trijet to dijet cross sections, is α s (M Z ) = 0.1179 ± 0.0013 (stat.) -0.0046 -0.0028 (exp.) -0.0046 +0.0064 (th.). © Springer-Verlag / Societa Italiana di Fisica 2005.