相关论文: Low-energy magnetic radiation: deviations from GOE
A pronounced spike at low energy in the strength function for magnetic radiation (LEMAR) is found by means of Shell Model calculations, which explains the experimentally observed enhancement of the dipole strength. LEMAR originates from…
The enhancement observed below 2 MeV in the radiative strength function of nuclei near closed shells is explained by shell model calculations as M1 transitions between excited states. In the open-shell a change to a bimodal structure…
Magnetic dipole strength functions have been deduced from averages of a large number of $M1$ transition strengths calculated within the shell model for the nuclides $^{90}$Zr, $^{94}$Mo, $^{95}$Mo, and $^{96}$Mo. An enhancement of $M1$…
We have made a thorough study of the low-energy behaviour of the $\gamma$-ray strength function within the framework of the shell model. We have performed large-scale calculations spanning isotopic and isotonic chains over several mass…
A low-energy enhancement (LEE), observed experimentally in the $\gamma$-ray strength function ($\gamma$SF) describing the decay of compound nuclei, would have profound effects on $r$-process nucleosynthesis if it persists in heavy…
We compute the magnetic dipole (M1) $\gamma$-ray strength functions ($\gamma$SF) for the odd-mass lanthanides $^{143-151}$Nd and $^{147-153}$Sm using the shell-model Monte Carlo method in combination with the static-path approximation and…
A strong enhancement at low $\gamma$-ray energies has recently been discovered in the $\gamma$-ray strength function of $^{56,57}$Fe. In this work, we have for the first time obtained theoretical $\gamma$ decay spectra for states up to…
The experimental $E1$ strength distribution below 4 MeV in rare-earth nuclei suggests a local breaking of isospin symmetry. In addition to the octupole states, additional $1^-$ states with enhanced E1 strength have been observed in…
A low-energy enhancement (LEE) has been observed in the deexcitation $\gamma$-ray strength function ($\gamma$SF) of compound nuclei. The LEE has been a subject of intense experimental and theoretical interest since its discovery, and, if…
Studies of the $\gamma$-ray strength functions can reveal useful information concerning underlying nuclear structure. Accumulated experimental data on the strength functions show an enhancement in the low $\gamma$ energy region. We have…
We present the first theoretical results of the magnetic dipole (M1) $\gamma$-ray strength function ($\gamma$SF) for actinide nuclei within the shell-model Monte Carlo (SMMC) method. We observe a low-energy enhancement (LEE) in the M1…
Radiative diagnostics of high-energy density plasmas is addressed in this paper. We propose that the radiation produced by energetic particles in small-scale magnetic field turbulence, which can occur in laser-plasma experiments,…
The review of possible stimulation mechanisms of LENR (low energy nuclear reaction) is represented. We have concluded that transmutation of nuclei at low energies and excess heat are possible in the framework of the modern physical theory…
Magnetars are neutron stars with superstrong magnetic fields which can exceed 1e15 G. Some magnetars (the so-called soft gamma-repeaters) demonstrate occasionally very powerful processes of energy release, which result in exceptionally…
Magnetic dipole strength functions are determined for the series of germanium isotopes from $N = Z = 32$ to $N$ = 48 on the basis of a large number of transition strengths calculated within the shell model. The evolution of the strength…
We study the information content carried by the electric dipole strength with respect to isovector and isoscalar indicators characterizing bulk nuclear matter and finite nuclei. To separate isoscalar and isovector modes, and low-energy…
Circularly polarized laser field causes a shift in the nuclear magnetic resonance (NMR) spectra of all substances. The shift is proportional to the intensity of the laser beam and yields oppositely signed values for left- and…
A strength function method is adopted to describe a coupling between electric and magnetic modes of different multipolarity. The collective vibrations are analysed for a separable residual interaction in the framework of the random-phase…
The Li-7(p,gamma_0)Be-8 reaction is studied in a microscopic cluster model. All relevant subsystem properties are well reproduced. The calculated astrophysical S factor is in good agreement with the experimental data, although some M1…
Some of the most energetic pulsars exhibit rotation-modulated gamma-ray emission in the $0.1$ to $100$ GeV band. The luminosity of this emission is typically $0.1\text{-}10\%$ of the pulsar spin-down power (gamma-ray efficiency), implying…