Finite-range Droplet Model Research Articles

Structural and decay properties of even–even trans-lead nuclei

A systematic study of the ground-state properties of even–even Po, Rn, Ra and Th isotopes is conducted using the self-consistent Skyrme-Hartree–Fock–Bogoliubov (HFB) theory. Different Skyrme interactions are employed in the study. The bulk properties such as binding energy, two-neutron separation energies, two-proton separation energies and neutron skin thickness are investigated. The obtained results from the Skyrme-HFB formalism are compared with the calculated results from the Finite Range Droplet Model (FRDM) and the available experimental data. Our theoretical values were found to be consistent with their counterparts. In addition, the density-dependent cluster model is utilized to estimate [Formula: see text]-decay half-lives. A good agreement is achieved between the calculated results and the recent experimental data.

Re-analysis of the Gamow-Teller distributions for [formula omitted] nuclei, 24Mg, 28Si, and 32S

The Gamow-Teller (GT) strength distributions of sd-shell N=Z nuclei (24Mg, 28Si, and 32S) are investigated within the framework of proton–neutron quasi-particle random phase approximation (pn-QRPA) using a deformed basis. The nuclear properties of these special nuclei were investigated by the Relativistic Mean Field (RMF) model. The RMF framework with density-dependent interactions (DD-PC1 and DD-ME2) was employed to compute ground-state deformation parameters (β2) using potential energy curves. The β2 values computed from the RMF and the finite range droplet model (FRDM) were employed as a free parameter in the pn-QRPA calculation to investigate the resulting GT strength distributions. The present model-based analyses compare well with the observed data.

Study on the decay of Z = 127 – 132 superheavy nuclei via emission of 1-n and 2-n halo nuclei

The barrier penetrability, decay constant and decay half-life of 1-n halo nuclei 11Be, 15,17,19C, 22N, 23O, 24,26F, 29,31Ne, 34,37Na, 35,37Mg, and 55Ca; and 2-n halo nuclei 22C, 27,29F, 34Ne, 36Na, and 46P from Z = 127 – 132 parents were calculated within the framework of the Coulomb and proximity potential model by calculating the Q-values using the finite-range droplet model. A comparison between the decay half-lives is made by considering the halo candidates as a normal cluster and as a deformed structure with a rms radius. Neutron shell closure at 190, 196, 198, 200, 204, and 208 are identified from the plot of decay half-lives versus the neutron number of daughter nuclei (NP). The calculation of alpha decay half-life and spontaneous decay half-life showed that the majority of the parent nuclei survive spontaneous fission and decay through alpha emission. The Geiger-Nuttall plots of log10T1/2 versus Q-1/2 and universal plots of log10T1/2 versus -lnP for the emission of all 1-n and 2-n halo nuclei from the parents considered here are linear and show the validity of Geiger - Nuttall law in the case of decay of halo nuclei from superheavy elements.

Nuclear mass predictions based on a deep neural network and finite-range droplet model (2012)* *H.L. acknowledges the JSPS Grant-in-Aid for Early-Career Scientists under Grant No. 18K13549, the JSPS Grant-in-Aid for Scientific Research (S) under Grant No. 20H05648, and the RIKEN Pioneering Project: Evolution of Matter in the Universe. J.L. acknowledges the Research Grants Council (RGC) of Hong Kong, China with

A neural network with two hidden layers is developed for nuclear mass prediction, based on the finite-range droplet model (FRDM12). Different hyperparameters, including the number of hidden units, choice of activation functions, initializers, and learning rates, are adjusted explicitly and systematically. The resulting mass predictions are achieved by averaging the predictions given by several different sets of hyperparameters with different regularizers and seed numbers. This can provide not only the average values of mass predictions but also reliable estimations in the mass prediction uncertainties. The overall root-mean-square deviations of nuclear mass are reduced from 0.603 MeV for the FRDM12 model to 0.200 MeV and 0.232 MeV for the training and validation sets, respectively.

Evaporation residue cross sections of superheavy nuclei based on optimized nuclear data* *Supported by the National Natural Science Foundation of China (12175170, 11675066)

This study proposes an optimized method for estimating atomic nucleus masses by combining the finite-range droplet model (FRDM) with the support vector machine algorithm. The optimization process significantly improves the accuracy of the FRDM by reducing the root mean square error from 0.606 to 0.253 MeV. The optimized mass data obtained from this method are then used to calculate the evaporation residue cross-sections (ERCSs) for fusion-evaporation reactions, employing the di-nuclear system model. The experimental results for the 48Ca+238U reaction are relatively well reproduced using these optimized mass data. Additionally, the study investigates the impact of mass uncertainties on fusion and survival probabilities. By considering the mass uncertainties, the ERCSs for new elements 119 and 120 are predicted based on the obtained optimized mass data.

Alpha decay and cluster radioactivity investigation of actinide nuclei

Based on the Unified Fission Model with a Woods–Saxon potential (UFMWS), we have investigated alpha decay and cluster radioactivity of actinide nuclei. To ensure accuracy, we determined the most precise [Formula: see text]-values by comparing the results of four nuclear mass models: the liquid drop model (LDM), the DZ28 model, the WS4 model, and the finite range droplet model (FRDM), which were recently improved using a machine learning algorithm. Among these models, it is found that the improved WS4 (IWS4) provides the most accurate [Formula: see text]-values, enabling the UFMWS model to effectively reproduce experimental alpha and cluster decay half-lives. Consequently, the UFMWS model using IWS4 [Formula: see text]-values was employed to explore various combinations of parent nuclei and alpha particle as well as even–even emitted clusters ranging from Be to Si. The obtained results are consistent with previous study that identified minima in half-lives near corresponding to the doubly magic [Formula: see text]Pb daughter nucleus or its neighboring nuclei. It is found that neutron-deficient parent nuclei generally displayed the shortest half-lives, most of which are within the experimental range. Considering the experimental limitations, cluster decays favorable for measurement in the actinide region were identified. Interestingly, these decays did not involve the most neutron-deficient nuclei.

Correlation between the nuclear structure and reaction dynamics of Ar-isotopes as projectile using the relativistic mean-field approach

This theoretical study is devoted to bridging the gap between the nuclear structure and reaction dynamics and unravelling their impact on each other, considering the neutron-rich light mass 30−60Ar isotopes. Using the relativistic mean-field with the NL3⁎ parameter set, several bulk properties such as binding energies, charge radii, quadrupole deformation parameter, two neutron separation energy, and differential two neutron separation energy with the shell closure parameter are probed for the mentioned isotopic chain. For validation, the RMF (NL3⁎) results are compared with those obtained from the finite range droplet model (FRDM), Weizsäcker-Skyrme model with WS3, WS⁎ parameters, and the available experimental data. Most of the participating isotopes are found to be prolate in structure, and neutron shell closures are conspicuously revealed at N=14,20,40 but weakly shown at N=24,28,34. From our analysis, a central depletion in the nucleonic density is identified in 32 Ar and 42−58 Ar, indicating that they are possible candidates for a semi-bubble-like structure. Interestingly, these results are consistent with recent theoretical and experimentally measured data. Furthermore, using the Glauber model, the reaction cross-sections are determined by taking 26−48Ar as projectiles and stable targets such as 12C, 16O, 40Ca, 90Zr, 124,132Sn, 208Pb and 304120. Although there is no experimental evidence for the stability of 304120, it was predicted by Bhuyan and Patra (2012) [115] as a stable nucleus. A relatively higher cross-section value is noticed between 30 Ar and 32 Ar, which infers that 32Ar is the most stable isotope among the considered chain. Moreover, we noticed that the profile of the differential cross-sections and scattering angle are highly influenced by the mass of the target nuclei and the magnitude of the incident energy of the projectile nucleus.

An empirical formula for the alpha decay half-lives

Using 377 available experimental data, we have obtained an empirical formula to calculate alpha decay half-lives based on Geiger–Nuttall law for even–even, even–odd, odd–even and odd–odd nuclei. The coefficients of Geiger–Nuttall law have been modified as a function of the atomic number of the parent nucleus and the orbital angular momentum. The obtained root mean square deviations from experimental half-lives for even–even, even–odd, odd–even and odd–odd nuclei are 0.3265, 0.5412, 0.4848 and 0.4353, respectively. For most nuclei, the obtained results from this formula are in good agreement with the experimental data. We compared our results with other formulas such as universal decay law, Royer, AKRA, MYQZR and Luo. Also, using this formula, we presented predictions for superheavy nuclei with [Formula: see text]–124 using the [Formula: see text]-values based on the finite range droplet model and Weizsäcker–Skyrme. It is found that the behavior of the half-life of alpha decay is sensitive to the used [Formula: see text]-values.

Theoretical studies on structural properties and decay modes of $$^{284-375}$$119 isotopes

Within the axially deformed relativistic mean field with $$\hbox {NL3}^*$$ parametrisation, the different bulk properties like binding energy, quadrupole deformation parameter, separation energies, density profile and shape co-existence for Z = 119 isotopic chain within the mass range 284 $$\le$$ A $$\le$$ 375 are computed. Further, a competition between possible decay modes such as α-decay, $$\beta$$ -decay and spontaneous fission (SF) of the isotopic chain of Z = 119 superheavy nuclei under study is systematically analysed within self-consistent relativistic mean field model and a close agreement is noticed among the calculations performed using various semi-empirical formulae and also with the estimations made by finite range droplet model (FRDM) wherever available. Our analysis confirmed that α–decay is restricted within the mass range 284 $$\le$$ A $$\le$$ 375 and thus being the dominant decay channel in this mass range and there is no possibility of $$\beta$$ –decay for the considered isotopic chain. In addition, we forecasted the α–decay chain of fission survival nuclides, i.e. $$^{284-296}119$$ and found as one α chain from $$^{284} 119$$ and $$^{296} 119$$ , $$2 \alpha$$ chains from $$^{285}119$$ and $$^{295} 119$$ consistently, $$3\alpha$$ chains from $$^{286} 119$$ and $$^{294} 119$$ consistently, $$4 \alpha$$ chains from $$^{287} 119$$ consistently, six consistent α chains from $$^{288-293} 119$$ . A comparative study of SF and α-decay half-live computed using the formula of Santhosh et al and Coulomb proximity potential model (CPPM), respectively, for the fission surviving isotopic chain reveals that isotopes $$^{288-293} 119$$ exhibit $$6\alpha$$ chains followed by SF, isotopes $$^{295,296} 119$$ exhibit $$4\alpha$$ chains followed by SF, and the rest of the nuclei show continuous α chains. This study has also established that the alpha half-life values computed using $$\hbox {Q}_\alpha$$ (RMF) agree with half-life values computed using experimental $$\hbox {Q}_\alpha$$ values within 1 order difference. Thus, such studies can be of great significance to the experimentalists in very near future for synthesizing the isotopes of Z = 119 superheavy nuclei.

Prediction of ground-state spin in odd-<i>A</i> nuclei within decision tree

Ground-state spin, as a fundamental parameter of nucleus, has consistently been a hot topic in research on nuclear data and structure. In this paper, we extensively investigate the odd-mass nuclei (odd-<i>A</i> nuclei) on the nuclide chart by using decision trees, including odd-proton nuclei (odd-<i>Z</i> nuclei) and odd-neutron nuclei (odd-<i>N</i> nuclei), and train ground-state spin prediction models of odd-<i>Z</i> nuclei and odd-<i>N</i> nuclei. In the case of randomly dividing the training set and validation set in a ratio of 75% to 25%, the accuracy rate of the training set and validation set for odd-<i>Z</i> nuclei reach 98.9% and 79.3%, respectively. The accuracy rate of the training set and validation set for the odd-<i>N</i> nuclei reach 98.6% and 71.6%, respectively. At the same time, by 1000 random selections of training set and validation set, after being validated repetitively, the standard error of the accuracy rate obtained can be less than 5%, further verifying the reliability and generalization performance of the decision tree. On the other hand, the accuracy rate of decision tree is much higher than those of theoretical models commonly used in nuclear structure research, such as Skyrme-Hartree-Fock-Bogoliubov, covariant density functional theory, and finite range droplet model. Next, by taking all spin-determined odd-<i>Z</i> nuclei and odd-<i>N</i> nuclei as a learning set, the ground-state spin values for 254 spin undetermined but recommended odd-<i>Z</i> nuclei and 268 spin undetermined but recommended odd-<i>N</i> nuclei are predicted, with the predicted set coincidence rates reaching 68.5% and 69.0%, respectively. Finally, four odd-mass number chains, i.e. <i>Z</i> = 59, <i>Z</i> =77, <i>N</i> = 41, and <i>N</i> = 59, are selected to compare the learning (prediction) results of the decision tree with the experimental (recommended) values of the corresponding nuclei, and to discuss the differences and similarities in the results given by the three theoretical models, thereby further demonstrating the research and application value of the decision tree in the ground-state spin of nuclei.

Properties and synthesis of the superheavy nucleus Fl114298

The one-nucleon separation energy ${S}_{n}$, two-nucleon separation energy ${S}_{2n}$, one-proton separation energy ${S}_{p}$, two-proton separation energy ${S}_{2p}, \ensuremath{\alpha}$-decay energy ${Q}_{\ensuremath{\alpha}}, \ensuremath{\alpha}$-decay half-life and spontaneous fission half-life of $Z=114$ isotopes and $N=184$ isotones are calculated by the finite-range droplet model (FRDM2012). It is found that $N=184$ is a neutron magic number, and $Z=114$ is a proton magic number. The properties of $Z=114$ isotopes and $N=184$ isotones provide a vital signal that $_{114}^{298}\mathrm{Fl}$ may be a spherical double-magic nucleus and also the center of the stability island of superheavy nuclei. Based on this, we began to investigate the optimal conditions for the synthesis of superheavy nucleus $_{114}^{298}\mathrm{Fl}$ within the dinuclear system model. To produce such neutron-rich compound nucleus, we consider using the extremely neutron-rich radioactive beams to bombard actinide targets. The evaporation residue cross section of superheavy nuclei synthesized by radioactive beam is analyzed in detail. Finally, we suggest that for the synthesis of $_{114}^{298}\mathrm{Fl}$, the radioactive beam-induced fusion reaction $^{64}\mathrm{Ti}+^{238}\mathrm{U}$ in the $4n$ evaporation channel with an excitation energy of 43 MeV is optimal.

Microscopic analysis of the ground state properties of the even-even Dy isotopes in the reflection-asymmetric relativistic mean-field theory

Reflection-asymmetric relativistic mean-field theory is used to explore the ground state properties for the even-even Dy isotopes. The results are compared with those from the finite-range droplet model (FRDM), the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc), and the available data. The calculated binding energies and quadrupole deformations agree with the experimental data as well as the FRDM and DRHBc calculations. The obtained matter density distributions and potential energy surfaces clearly exhibit the ground state shapes and the presence of deformation in these nuclei. The experimental fingerprints of octupolarity in $^{148,154,156,160}\mathrm{Dy}$ around $N=88$ are convincing in the present calculations. The predictions on the octupole deformation in $^{190\text{--}194,200,202}\mathrm{Dy}$ around $N=134$ agree with the results from the FRDM calculations. In addition, we obtain more knowledge about the shape evolution and phase transition from oblate to pear shape and then to prolate shapes in the Dy isotopes.

Examination of Astrophysical S-Factor and Non-Resonant Rates of the 64Ge(p,γ)65As Reaction

The 64Ge(p,γ)65As reaction rates strongly impact the predictions of the energy generation and isotopic abundance in the rp-process in X-ray bursts. However, the rates are ambiguous at present due to the lack of experimental cross section and the uncertainty in the non-resonant reaction rates. To provide informative data for the astrophysical rates of the 64Ge(p,γ)65As reaction, we evaluate the astrophysical S factor and direct capture rates of the 64Ge(p,γ)65As reaction using the cross sections relied on the statistical theory with various mass models. The S factors at 0 energy were found to be S(0) = 7.2×105 and 1.1×106 MeV.barn for the Finite-Range Droplet Model (FRDM) and the extended Thomas-Fermi (ETFSI) mass models, respectively. These values are about 4 orders of magnitude different from the value obtained in previous study. The empirical parameters for the non-resonant-rate approximations were also deduced for the 64Ge(p,γ)65As reaction and its photodisintegration. By considering the results in this study together with those obtained in the previous work, we confirm that a strong waiting point at the 64Ge nucleus is still a doubt because of large uncertainty of the S factor and non-resonant rates. The results in this study are useful for a better understanding of the X-ray burst properties and reaction flow at 64Ge in the rp-process.
 HIGHLIGHTS
 
 Large discrepancy up to 4 orders of magnitude in the S factor at zero energy was found
 The strength of the waiting point at 64Ge in the rp-process is still questionable
 The astrophysical rates of the 64Ge(p,γ)65As reaction are very uncertain due to the S-factor uncertainty
 The non-resonant rates of the 64Ge(p,γ)65As reaction estimated using statistical method are not significantly impacted by the FRDM and ETFSI mass models
 
 GRAPHICAL ABSTRACT

Structure and decay chain of fermium isotopes using relativistic mean-field approach

In this paper, we have analyzed the ground state structural properties of fermium-isotopes in the mass range [Formula: see text] within the relativistic mean-field with NL3[Formula: see text] and Relativistic Hartree–Bogoliubov approach with DD-ME2 parameter sets. The bulk properties, such as binding energy, root mean-square charge radius, quadruple deformation parameter, chemical potentials, two-neutron separation energy and differential two- neutron separation energy, are estimated for the above Fm- isotopic chain. All the calculated observables are compared with finite range droplet model (FRDM) predictions and experimental data wherever available. The analysis predicts the existence of shell closure in the neutron-rich region of the isotopic chain at [Formula: see text]. The decay properties such as the [Formula: see text]-decay energy and corresponding half-life for three decay chains i.e. [Formula: see text]Fm, [Formula: see text]Fm and [Formula: see text]Fm are studied. Six different empirical formulae, namely; Viola-Seaborg, Royer, modified B. Alex Brown, Parkhomenko–Sobiczewski, Universal decay law and modified universal decay law are employed to ascertain the numerical dependency of the half-life for each decay energy. A comparative study of [Formula: see text]-values and half-lives for these decay chains gives a good signature of the calculated results. The half-life calculations of three decay chains suggest that [Formula: see text]Pu, [Formula: see text]Pu, [Formula: see text]Pu are shell closure nuclei having maximum half-lives, whereas [Formula: see text]Fm, [Formula: see text]Fm and [Formula: see text]Fm are shell stabilized with lower half-lives.

Deep learning approach to nuclear masses and α -decay half-lives

Ab-initio calculations of nuclear masses, the binding energy and the $\alpha$ decay half-lives are intractable for heavy nucleus, because of the curse of dimensionality in many body quantum simulations as proton number($\mathrm{N}$) and neutron number($\mathrm{Z}$) grow. We take advantage of the powerful non-linear transformation and feature representation ability of deep neural network(DNN) to predict the nuclear masses and $\alpha$ decay half-lives. For nuclear binding energy prediction problem we achieve standard deviation $\sigma=0.263$ MeV on 10-fold cross validation on 2149 nuclei. Word-vectors which are high dimensional representation of nuclei from the hidden layers of mass-regression DNN help us to calculate $\alpha$ decay half-lives. For this task, we get $\sigma=0.797$ on 100 times 10-fold cross validation on 350 nuclei on $log_{10}T_{1/2}$ and $\sigma=0.731 $ on 486 nuclei. We also find physical a priori such as shell structure, magic numbers and augmented inputs inspired by Finite Range Droplet Model are important for this small data regression task.

Ground state properties of polonium isotopes using covariant density functional theory

In the framework of the Relativistic Hartree-Bogoliubov (RHB) mean-field model, a Covariant Density Functional Theory (CDFT) is used to systematically investigate the triaxial shape evolution of even–even polonium isotopic chain (N = 102–148). Two different effective interactions, i.e. the Density-Dependent Meson-Exchange (DD-ME2) and the new parameter set of Density-Dependent Point-Coupling (DD-PCX) interactions, are utilized in the current study. Besides, the new parameter-free proxy-SU(3) model is used to investigate the ground state shapes of polonium isotopes. CDFT calculations with both parameter sets, predict shape coexistence in the neutron deficient side of polonium isotopic chain, which meets the same prediction of the proxy-SU(3) scheme. The predicted shapes of nuclei are in good agreement with several experimental studies, as well as other theoretical models presented in the current paper. Also, one triaxial ground state is predicted by DD-ME2, DD-PCX, and proxy-SU(3) but for three different nuclei. Different ground state properties like binding energy per nucleon, two-neutron separation energy and proton- neutron- and charge radii are presented in comparison with available experimental data as well as other theoretical models, like the Finite-Range Droplet Model (FRDM), the Infinite Nuclear Matter Model (INMM) and Deformed Relativistic Hartree-Bogoliubov theory in Continuum (DRHBc).

Learning correlations in nuclear masses using neural networks

There have been great improvements in the predictions of nuclear masses, yet it is difficult to exactly reproduce the measured nuclear mass. It has been suggested that the cause of such discrepancies is due to the negligence of many-body effects in the available theoretical models. The errors in the prediction of the nuclear mass show residual correlations due to the missing physics in the mass models. In the present Letter we have tried to learn such correlations by using the neural networks. We have used a neural network architecture which adaptively learns the linear and nonlinear correlations between the data of different fidelity. We have used the theoretical predictions of finite range droplet model and Hartree- Fock-Bogoliubov models in the input of the neural networks. The present approach show significant improvements in the accuracy of the predictions. It has been clearly presented that the difference between the predictions from the present approach and the experimental data behave more, such as white noise, showing that using the present approach the residual correlations arising due to the missing physics from the available mass models can be learned.

Structure and decay modes study of Th, U, and Pu isotopes using relativistic mean field model

In the present work, we have studied the structural properties, alpha and clusters (8Be, 12C, 16O, 20Ne, and 24Mg) decay half-lives for the Th, U, and Pu isotopes using the well-known Relativistic Mean-Field (RMF) theory with NL3* parameter set. We calculate the binding energy per nucleon, root-mean-square (rms) radii, two-neutron separation energies (S2n), and other observables. The results are in good agreement with the finite-range droplet model (FRDM) and experimental data. Using the calculated mass defect results from these calculations, the Effective liquid drop model (ELDM) has been used to determine alpha and cluster decay half-lives. The half-lives calculations are also carried out by using the latest empirical relations, namely Universal Decay Law (UDL), TM, VS, and the Scaling Law was given by Horoi et al., and their comparisons with ELDM results are found to be in good agreement. In the plots for log10T1/2 versus the neutron number of the daughter nucleus Nd in the corresponding decay, the half-life is found to have a minimum for the decay leading to nearly doubly magic or doubly magic daughter 208Pb nucleus (Nd=126). The Geiger-Nuttal plots for different clusters from various cluster radioactive (CR) emitters have been studied and they clearly show a linear behavior.

Structural evolution and shape transition in even-even Hf-isotopes within the relativistic mean-field approach

In this theoretical study, we calculate the ground state parameters like binding energy, charge radii, neutron skin-thickness, chemical potentials, quadrupole deformation parameter, neutron separation energy, and single-particle energy for Hf isotopes of mass 170 ⩽ A ⩽ 220. The potential energy surface in parallel with the Fermi energy as a function of the quadrupole deformation parameter is estimated to determine the ground state configuration. The Relativistic Hartree-Bogoliubov approach with density-dependent DD-ME2 and the relativistic mean-field formalism with the popular NL3 and NL3⁎ parameter sets are used for the present analysis. The study involves a constant gap BCS approach within NL3, & NL3⁎ and Bogoliubov transformation within DD-ME2 parameter sets to examine the effect of pairing correlations. The calculated bulk quantities are reasonably good agreement with available experimental data, the finite range droplet model predictions, and the Weizsäcker-Skyrme mass formula. We find the signature of shell/sub-shell closure at N = 126 for all the parameter sets, which indicates the stability of 198Hf in the neutron drip-line region of the Hf-isotopes.

Divergence in the Relativistic Mean Field Formalism: A Case Study of the Ground State Properties of the Decay Chain of 214,216,218U Isotopes

A new α-emitting 214U has been recently observed experimentally. This opens the window to theoretically investigate the ground-state properties of the lightest known even–even neutron deficient 214,216,218U isotopes and to examine α-particle clustering around the shell closure. The decay half-lives are calculated within the preformed cluster-decay model (PCM). To obtain the α-daughter interaction potential, the RMF densities are folded with the newly developed R3Y and the well-known M3Y NN potentials for comparison. The alpha preformation probability (Pα) is calculated from the analytic formula of Deng and Zhang. The WKB approximation is employed for the calculation of the transmission probability. The individual binding energies (BE) for the participating nuclei are estimated from the relativistic mean-field (RMF) formalism and those from the finite range droplet model (FRDM) as well as WS3 mass tables. In addition to Z=84, the so-called abnormal enhancement region, i.e., 84≤Z≤90 and N<126, is normalised by an appropriately fitted neck-parameter ΔR. On the other hand, the discrepancy sets in due to the shell effect at (and around) the proton magic number Z=82 and 84, and thus a higher scaling factor ranging from 10−8–10−5 is required. Additionally, in contrast with the experimental binding energy data, large deviations of about 5–10 MeV are evident in the RMF formalism despite the use of different parameter sets. An accurate prediction of α-decay half-lives requires a Q-value that is in proximity with the experimental data. In addition, other microscopic frameworks besides RMF could be more reliable for the mass region under study. α-particle clustering is largely influenced by the shell effect.