Magnetic Field Effect on β^＋ Decay in the Crusts of Accreting Neutron Stars

Based on shell model of nuclei, the influence of a high magnetic field on β^＋ decay in the crusts of accreting neutron stars is analyzed. The magnetic field effect on 54 Mn is discussed. The results show that a weak magnetic field makes little effect on β^＋ decay but a strong magnetic field （B 〉 10^11 G） improves β^＋ decay rates obviously. The conclusion derived will benefit to develop further research on nuclear astrophysics in the future.     

Isovector Giant Dipole Resonance of Stable Nuclei in a Consistent Relativistic Random-phase Approximation

A fully consistent relativistic random-phase approximation is applied to study the systematic behaviour of the isovector giant dipole resonance of nuclei along the β-stability line in order to test the effective Lagrangians recently developed. The centroid energies of response functions of the isovector giant dipole resonance for stable nuclei are compared with the corresponding experimental data and the good agreement is obtained. It is found that the effective Lagrangian with an appropriate nuclear symmetry energy, which can well describe the ground state properties of nuclei, could also reproduce the isovector giant dipole resonance of nuclei along the β-stability line.     

NMR evidence of charge fluctuations in multiferroic CuBr_2

We report combined magnetic susceptibility, dielectric constant, nuclear quadruple resonance(NQR), and zero-field nuclear magnetic resonance(NMR) measurements on single crystals of multiferroics CuBr_2. High quality of the sample is demonstrated by the sharp magnetic and magnetic-driven ferroelectric transition at T_N= T_C≈ 74 K. The zero-field ~(79)Br and ~(81)Br NMR are resolved below T_N. The spin-lattice relaxation rates reveal charge fluctuations when cooled below 60 K.Evidences of an increase of NMR linewidth, a reduction of dielectric constant, and an increase of magnetic susceptibility are also seen at low temperatures. These data suggest an emergent instability which competes with the spiral magnetic ordering and the ferroelectricity. Candidate mechanisms are discussed based on the quasi-one-dimensional nature of the magnetic system.     

Shell model calculations for the allowed Gamow-Teller β-decays of light nuclei

The allowed Gamow-Teller β-decay information of Li,Be,B,C,and N isotopes under the frame work of nuclear shell model is calculated herein.Theoretical results of Q values,half-lives,excitation energies,log ft values,branching fractions,and β-delayed proton/neutron emission probabilities are tabulated and compared with experimental data.The deviations from the observations are also analyzed.The 11Be nucleus is well known for its anomaly ground state Jπ=1/2+.Thus,we compared the theoretical energy levels with the experimental data and the agreements for low excitation states are consistent.The quenching factor is also evaluated and discussed.     

NMR analogue of the generalized Grover＇s algorithm of multiple marked states and its application

The generalized Grover‘s algorithm for the case in which there are multiple marked states is demonstrated on a nuclear magnetic resonance (NMR) quantum computer. The Walsh-Hadamard transform and the phase inversion are all replaced. NMR analogues of Einstein-Podolsky-Rosen states (pseudo-EPR states) are synthesized using the above algorithm.     

NMR analogue of the generalized Grover‘s algorithm of multiple marked states and its application

The generalized Grover's algorithm for the case in which there are multiple marked states is demonstrated on a nuclear magnetic resonance (NMR) quantum computer. The Walsh－Hadamard transform and the phase inversion are all replaced. NMR analogues of Einstein－Podolsky－Rosen states (pseudo-EPR states) are synthesized using the above algorithm.     

Precise measurement of magnetic moment of short-lived β-emitting nuclei ~(12)B (I~π=1~+,T_(1/2)=20.18 ms)

1 Introduction The production of nuclear spin polarization and the maintenance of the nuclear po-larization in a stopper are the essential requirement for the measurement of nuclear magnetic and electric quadrupole moments of the b-emitting nuclei by the ?NMR and b-NQR (b-ray detected Nuclear Magnetic Resonance and b-ray detected Nuclear Quad-rupole Resonance) technique. This requirement can be realized by the selection tech-nique of the incident particle energy of the nuclear reaction th…     

Nuclear Current and Magnetic Rotation

The magnetic rotational bands based on the configuration πh11/2^2 vh11/2^-2 in ^142Gd are investigated with the newly developed tilted axis cranking relativistic mean field （RMF） theory with and without nuclear current. The effect of the nuclear current is discussed by comparing the total Routhians, single particle levels, electromagnetic transition probabilities B（M1） and B（E2） in self-consistent tilted axis cranking RMF caIculation with those obtained without the nuclear current. The nuclear currents are found to play an important role in the magnetic rotation of nuclei.     

Structure of β-emitting nuclei 29P

The extoic structure of ²⁹P was investigated by measuring its magnetic moment in the ground state with β-NMR method. We got the experimental value of 1.2346 μ_N after diamagnetism correction. It is very close to the calculated value of 1.1009 μ_N computed with shell model. The shell model calculation also gave a proton density distribution of ²⁹P with a long tail. The present results show that 2s_1/2 proton in the ²⁹P may lead to the proton-skin structure.