International Journal of Modern Physics E

In this paper, the investigations have been conducted on the half-lives of proton radioactivity of 32 nuclei. The main goal of the paper is to improve the formation probability (S_p) that proposed by Chen et al. [Eur. Phys. J. A  57 (2021) 1]. The obtained results in mentioned paper have been reproduced with uncertainties for all parameters by fitting the experimental data of proton emitters. To carry out the further investigations, we have proposed a new S_p which has a different type of shape from linear. The replacement of the linear form with an exponential, one of the formation probabilities, has affected the rms result positively. The new form of S_p, which has been presented in this study, depends on the mass number of daughter nucleus like the previous one but in exponential form. The obtained findings here may be important for studies while making new predictions.

In this paper, we look for a novel analytical solution of the Bohr Hamiltonian in the presence of the Hulthen plus screened Kratzer potential in $\beta$-part of the collective nuclear potential. The new expression for the energy spectra is obtained using the method of super symmetric quantum mechanics. The effect of the Hulthen plus screened Kratzer potential is studied on root mean square deviation, and normalized eigen energies of ground state band, $\gamma$-band and $\beta$-band of ¹⁹²Pt, ¹⁹⁴Pt and ¹⁹⁶Pt atomic nuclei. The $B(E2)$ transition rates are calculated for the latter potential. Furthermore, our results are compared with experimental data, and other relevant theoretical works. We discuss on how the combination of these two potentials makes it possible to improve the results of energy spectra and quadrupole transitions of triaxial nuclei. We discuss the quantitative and qualitative descriptions concerning the structure of the nucleus using some indicators such as root mean square and staggering of the $\gamma$-band. The results provided by our model are found to be in good agreement with experimental data and improved in comparison with previous works.

Theoretical nuclear reaction codes are crucial for studying cross-section and S-factors of nuclear reactions required for the thermonuclear reaction rate calculations. We analyze two reactions ⁸Li($\alpha ,n$)¹¹B and ¹⁴N($p,\gamma$)¹⁵O, using both TALYS and EMPIRE codes. We stress that these reactions are highly important for CNO cycle but the extent of involvement of experimental datasets are meager and conflicting. For the first reaction, the trend of experimental data has been predicted satisfactorily by the codes. The reaction rate is also matched with REACLIB calculation. However, in ¹⁴N($p,\gamma$)¹⁵O, none of the codes could predict the resonant structures in the experimental data at the lower energies. The importance of our work is a sincere attempt to validate the TALYS and EMPIRE predictions for cross-section, S-factor and the reaction rate, simultaneously.

Excited states of ¹¹⁷Sn have been populated using the fusion-evaporation reaction ¹¹⁴Cd(⁷Li, 1p3n) at a beam energy of 48MeV. A total of nine new transitions have been identified and added into the level scheme of ¹¹⁷Sn. Based on the systematical comparisons with the neighboring Sn isotopes and the configuration-fixed constrained triaxial relativistic mean-field (RMF) calculations, a collective structure and two isomers are proposed to exist in ¹¹⁷Sn. The phenomenon of shape coexistence has been extended to A = 117 in odd-A Sn isotopes for the first time.

In this work, we calculate the mass spectrum of the bottom mesons with a modified nonrelativistic quark model by involving the screening effect, and explore their strong decay properties within the ³P₀ model. Our results suggest that the $B_1(5721)$, $B_2^{\ast }(5747)$, $B_J(5840)$ and $B_J(5970)$ could be reasonably assigned as the $B_1^{\prime }(1P)$, $B(1^3{P}_2)$, $B(2^1{S}_0)$ and $B(1^3{D}_3)$, respectively. The more precise measurements of the excited bottom mesons are crucial to confirm these assignments.

The Jost functions, constructed by fitting available partial cross-sections for the elastic p ⁷Be scattering with $J^{\pi }=3^{+},2^{-}$, are analytically continued to complex energies, where the resonances are located as their zeros. In addition to the resonance energies and widths, the residues of the $S$-matrix at the corresponding poles, as well as the Asymptotic Normalization Constants (ANC) are determined. The fitting is done using the semi-analytic representation of the Jost function with proper analytic structure, defined on the Riemann surface whose topology involves not only the square-root but also the logarithmic branching caused by the Coulomb interaction.

Cluster preformation probability in heavy nuclei is studied using the empirical formula of Ni and Zhou [Ren. Phys. Rev. C  82 (2010) 24311]. Dong et al. [Eur. Phys. J. A  41 (2009) 197–204], and four new formulae of Santhosh et al. [Indian J. Phys.  95 (2021) 121]. The predictions of these formulae are then compared to the preformation probabilities extracted from the experimental decay half-lives using the generalized liquid drop model (GLDM), density-dependent cluster model (DDCM), and unified fission model (UFM). It has been found that except for the isospin-dependent formula of Santhosh et al., all other formulae predict much larger preformation probability than the experimentally extracted values. Further, we propose four new empirical formulae for the cluster preformation probability in heavy nuclei, and the predictions are compared to the experimentally extracted values using different theoretical models. It is found that the predictions of all the four proposed formulae are in good agreement with the predictions of various theoretical models.

The mass spectra and decay properties of $B$ and $B_s$ mesons are obtained using the nonrelativistic potential model by applying the variational approach. The quark–anti-quark potential used in our model consists of a Hulthen potential and a confining linear potential. The hyper-fine interaction is introduced to obtain the splittings of the spin-singlet and triplet states, while the spin–orbit and tensor interactions provide the fine structure splittings. The model parameters and the wave functions that reproduce the mass spectra are used to investigate the decay properties of $B$ and $B_s$ mesons. The mass spectra of $B$ and $B_s$ mesons have been enhanced using coupled channel effects.

Based on the similarity renormalization group (SRG) method, proton and neutron asymmetry in the nuclear pseudospin is investigated for the deformed system. We have checked influences of every term on the proton pseudospin splitting and their correlation with nuclear deformation. Further, we have found that dynamical term always made a similar effect on the proton pseudospin symmetry (PSS), which is different from the neutron case. By exerting its influence on the dynamical term, the vector–isovector $V_{\rho }$ potential gives the main contribution to the isospin asymmetry in the PSS except for several deeply bound states. The phenomenon that isospin asymmetry in the PSS becomes worse for the levels closer to the continuum and its reasons is disclosed.

In this paper, the fission of the single stars and galaxies in the mass-asymmetry (mass transfer) coordinate is considered. Using the potential energy derived as a function of mass asymmetry, the possibility of the formation of binary stars (binary galaxies) from the single stars (single galaxies) is studied.