An improved semi-empirical relationship for cluster radioactivity half-lives is proposed by introducing an accurate charge radius formula and an analytic expression of the preformation probability. Then, the cluster radioactivity half-lives for the daughter nuclei around 208Pb or its neighbors and the 12C radioactivity half-life of 114Ba are calculated within the improved semi-empirical relationship. It is shown that the accuracy of the new relationship is improved significantly compared to its predecessor. In addition, the cluster radioactivity half-lives that are experimentally unavailable for the trans-lead and trans-tin nuclei are predicted by the new semi-empirical formula. These predictions might be useful for searching for the new cluster emitters of the two islands in future experiments.
In this paper, we study the dynamics of k-essence in loop quantum cosmology (LQC). The study indicates that the loop quantum gravity (LQG) effect plays a key role only in the early epoch of the universe and is diluted at the later stage. The fixed points in LQC are basically consistent with that in standard Friedmann-Robertson-Walker (FRW) cosmology. For most of the attractor solutions, the stability conditions in LQC are in agreement with that for the standard FRW universe. But for some special fixed point, more tighter constraints are imposed thanks to the LQG effect.
In this work, we study the direct-detection constraints of light dark matter in the next-to minimal supersymmetric standard model (NMSSM) with non-universal Higgs masses (NUHM), especially the correlation between higgsino asymmetry and spin-dependent (SD) cross section. Finally, we get the following conclusions: (i) The SD cross section is proportional to the square of higgsino asymmetry in dark matter
The light-by-light (LBL) scattering with initial polarized Compton backscattered photons at the CLIC, induced by axion-like particles (ALPs), is investigated. The total cross sections are calculated, assuming CP-even coupling of the pseudoscalar ALP to photons. The 95% C.L. exclusion region for the ALP mass
The model for the cold-fusion reactions related to the synthesis of super-heavy nuclei in collisions of heavy projectile-nuclei with 208Pb target nucleus is discussed. In the framework of this model the production of the compound nucleus by two paths through, the di-nuclear system and the fusion way, are taken into account simultaneously. The formation of the compound nucleus in the framework of the di-nuclear system is related to the transfer of nucleons from the light nucleus to the heavy one. The fusion way is linked to the sequential evolution of the nuclear shape from the system of contacting nuclei to the compound nucleus. It is shown that the compound nucleus is mainly formed by the fusion way in the cold-fusion reactions. The landscape of the potential energy related to the fusion path is discussed in detail. This landscape for very heavy nucleus-nucleus systems has the intermediate state, which is linked to the formation of both the compound nucleus and the quasi-fission fragments. The decay of the intermediate state is taken into account in the calculation of the compound nucleus production cross sections and the quasi-fission cross sections. The values of the cold-fusion cross sections obtained in the model are well agreed with the experimental data.
The 218Ac and 221Th nuclide were produced via the heavy-ion induced fusion evaporation reaction 40Ar + 186W. Their decay properties were studied with the help of the gas-filled recoil spectrometer SHANS and the digital data acquisition system. The cross section ratio between 222Pa and 218Ac was extracted to be 0.69(9) experimentally. Two new possible α decay branches were suggested to 221Th. The valence neutron configurations for the daughter 217Ra were discussed by the hindrance factors.
This investigation seeks to find an appropriate dinuclear system for the formation of
By duality approach, we study condensate mass of QCD vacuum via dilaton wall background in presence of parameter
We investigate the thermodynamics and stability of the horizons in warped anti-de Sitter black holes of the new massive gravity under the scattering of a massive scalar field. Under scattering, conserved quantities can be transferred from the scalar field to the black hole, which change the state of the black hole. We determine that the changes in the black hole are well coincident with the laws of thermodynamics. In particular, the Hawking temperature of the black hole cannot be zero in the process as per the third law of thermodynamics. Furthermore, the black hole cannot be overspun beyond the extremal condition under the scattering of any mode of the scalar field.
The discovery of
The dependence of the proton decay half-lives on nuclear asymmetry parameter has been investigated using WKB method and two types of empirical formulas. Using single-folding formalism with asymmetry dependent nuclear radius and surface diffuseness of nuclear matter, the nuclear potential and consequently the half-life are functions of the asymmetry factor. Despite small values of asymmetry in neutron deficient proton emitters, noticeable changes in half-lives are observed. Addition of an asymmetry parameter term to the two forms of empirical formulas leads to a reduction in the rms error for ground state and isomeric transitions. Noticeable reduction of about 43% is obtained for isomeric transition in the second form of empirical formula. Considering ground state transitions in two categories, odd-even and odd-odd emitters, and adopting deformation and asymmetry dependent empirical formulas, the rms decreases remarkably. The lowest values of rms errors, viz. 0.1492, 0.2312, and 0.1999, are obtained for the mentioned empirical formulas of ground state transitions of odd-even and odd-odd emitters and all isomeric transitions, respectively.
In this paper, we study three scalar fields, quintessence field, phantom field and tachyon field, to explore the source of dark energy via the Gaussian processes method from the background and perturbation growth rate data. The corresponding reconstructions all suggest that the dark energy should be dynamical. Moreover, the quintom field, a combination between quintessence field and phantom field, is powerfully favored by the reconstruction. Their mean values indicate that the potential
We investigate the exotic
We investigate the prospects for discovering the Flavour Changing Neutral Current (FCNC)
In this paper, we consider a set of new symmetry in the SM, diagonal reflection symmetries
This work suggests a new quintessence anisotropic compact stars model in the
We study coupled dynamics of hydrodynamic fields and order parameter in the presence of nontrivial longitudinal flow using the chiral fluid dynamics model. We find the longitudinal expansion provides an effective relaxation for the order parameter, which equilibrates in an oscillatory fashion. Similar oscillations are also visible in hydrodynamic degrees of freedom through coupled dynamics. The oscillations are reduced when dissipation is present. We also find the quark density initially peaked at the boundary of boost invariant region moves toward forward rapidity with the peak velocity correlated with velocity of longitudinal expansion. The peak gets broadened during the evolution. The corresponding chemical potential rises due to simultaneous dropping of density and temperature. We compare the cases with and without dissipation for the order parameter, and also the standard hydrodynamics without order parameter. We find the corresponding effect on temperature and chemical potential can be understood from the conservation laws and different speed of equilibration of order parameter in the three cases.
Many experiments have confirmed the spectral hardening in a few hundred GV of cosmic ray (CR) nuclei spectra, and 3 different origins have been proposed: the primary source acceleration, the propagation, and the superposition of different kinds of sources. In this work, the break power law has been employed to fit each of the AMS-02 nuclei spectra directly when the rigidity greater than 45 GV. The fitting results of the break rigidity and the spectral index differences less and greater than the break rigidity show complicated relationships among different nuclei species, which could not been reproduced naturally by a simple primary source scenario or a propagation scenario. However, with a natural and simple assumption, the superposition of different kinds of sources could have the potential to explain the fitting results successfully. CR nuclei spectra from one single experiment in future (such as DAMPE) will provide us the opportunity to do cross checks and reveal the properties of the different kinds of sources.
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