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Nuclear surface diffuseness in cluster decay 团簇衰变中的核表面扩散
IF 2.8 4区 物理与天体物理
Pramana Pub Date : 2023-02-20 DOI: 10.1007/s12043-022-02510-z
L Vasanthi, N S Rajeswari
{"title":"Nuclear surface diffuseness in cluster decay","authors":"L Vasanthi,&nbsp;N S Rajeswari","doi":"10.1007/s12043-022-02510-z","DOIUrl":"10.1007/s12043-022-02510-z","url":null,"abstract":"<div><p>Yukawa-plus-exponential potential, a generalisation of modified liquid drop model, incorporates the finite range of nuclear force and diffuse nuclear surface. The range of Yukawa folding function, <i>a</i>, accounts for both surface diffuseness and saturation condition. The present study deals with the influence of <i>a</i>, in experimentally identified cluster decay of heavy nuclei. Further, its dependence on neutron excess of the parent nucleus, has been studied. For the experimentally identified cluster emitters, systematic calculations for values of <i>a</i> between 0.54 fm and 0.8 fm have been carried out. The results suggest that as <i>a</i> increases, the nuclear interaction potential widens and deepens, which subsequently influences the total potential. The study shows the dependence of surface diffuseness on neutron excess of isotopes of a parent nucleus. A correlation between <i>a</i>, corresponding to the best-matching half-lives with experimental ones, and the neutron excess of the corresponding parent nuclei has been carried out with an appropriate fitting function. Based on the good agreement between the calculated and experimental half-lives and the branching ratio for cluster emission relative to alpha, the analysis has been extended to alpha and cluster emission of heavy and superheavy nuclei in the range <span>(99le Z le 116)</span> with <span>(252 le A le 293)</span>. Half-lives of alpha decay of the superheavy nuclei match reasonably well with the experimental values. Predicted half-lives of the clusters, <span>(^{46})</span>Ar and <span>(^{48})</span>Ca from <span>(^{253})</span>Es and <span>(^{252})</span>Fm respectively, compare well with other predictions.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"97 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4791459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Correction: Spontaneous symmetry breaking and massive photons from a Fresnel-type potential 修正:自发对称性破缺和菲涅耳型势的大质量光子
IF 2.8 4区 物理与天体物理
Pramana Pub Date : 2023-02-17 DOI: 10.1007/s12043-023-02518-z
Rami Ahmad El-Nabulsi, Waranont Anukool
{"title":"Correction: Spontaneous symmetry breaking and massive photons from a Fresnel-type potential","authors":"Rami Ahmad El-Nabulsi,&nbsp;Waranont Anukool","doi":"10.1007/s12043-023-02518-z","DOIUrl":"10.1007/s12043-023-02518-z","url":null,"abstract":"","PeriodicalId":743,"journal":{"name":"Pramana","volume":"97 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4680235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Elastic scattering analysis using different phenomenological and microscopic potentials for ({}^{7})Li (+ {}^{27})Al system 利用不同现象学和微观势对({}^{7}) Li (+ {}^{27}) Al体系进行弹性散射分析
IF 2.8 4区 物理与天体物理
Pramana Pub Date : 2023-02-17 DOI: 10.1007/s12043-023-02515-2
Sh Hamada, Norah A M Alsaif, M El-Azab Farid, B M Alotaibi, Mohammed Alotiby, Awad A Ibraheem
{"title":"Elastic scattering analysis using different phenomenological and microscopic potentials for ({}^{7})Li (+ {}^{27})Al system","authors":"Sh Hamada,&nbsp;Norah A M Alsaif,&nbsp;M El-Azab Farid,&nbsp;B M Alotaibi,&nbsp;Mohammed Alotiby,&nbsp;Awad A Ibraheem","doi":"10.1007/s12043-023-02515-2","DOIUrl":"10.1007/s12043-023-02515-2","url":null,"abstract":"<div><p>Experimental <span>({}^{7})</span>Li<span>(+ {}^{27})</span>Al elastic scattering angular distributions in the 6–89 MeV laboratory energy range have been re-analysed using different phenomenological and microscopic potentials to investigate the cluster nature of the weakly-bound <span>({}^{7})</span>Li projectile and the associated break-up effect on the elastic scattering data. The consistency of the results obtained within the various implemented potentials was also analysed. A new microscopic dynamical polarisation potential was applied to simulate the significant coupling effect to the break-up channel, which is responsible for the observed reduction in the strength of the implemented real potentials. A reasonable agreement between the considered experimental results and the present theoretical calculations was obtained. The study confirms the absence of the usual threshold anomaly present in nuclear systems involving tightly-bound projectiles.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"97 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4675113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Occurrence of non-smooth bursting oscillations in a Filippov system with slow-varying periodic excitation 具有慢变周期激励的Filippov系统中非光滑爆破振荡的发生
IF 2.8 4区 物理与天体物理
Pramana Pub Date : 2023-02-16 DOI: 10.1007/s12043-023-02516-1
Yawei Ge,  JuntingGou, Xiaofang Zhang, Qinsheng Bi
{"title":"Occurrence of non-smooth bursting oscillations in a Filippov system with slow-varying periodic excitation","authors":"Yawei Ge,&nbsp; JuntingGou,&nbsp;Xiaofang Zhang,&nbsp;Qinsheng Bi","doi":"10.1007/s12043-023-02516-1","DOIUrl":"10.1007/s12043-023-02516-1","url":null,"abstract":"<div><p>The main purpose of this paper is to explore the mechanism of the non-smooth bursting oscillations in a Filippov neuronal model with the coupling of two scales and to try to explain some special phenomena appearing on the attractors. Based on a typical Hindmarsh–Rose neuronal model, when the recovery variable of the slow current is replaced by a slow-varying periodic excitation, which means the exciting frequency is far less than the natural frequency, the coupling of two scales in frequency exists, leading to the non-smooth bursting oscillations. By regarding the whole exciting term as a slow-varying parameter, we can define the full subsystem as Filippov type, which appears in generalised autonomous form. Equilibrium branches and their bifurcations of the fast subsystem can be derived by varying the slow-varying parameter. With the increase of the exciting amplitude, different types of equilibrium branches and the bifurcations may involve the slow–fast vector field, which may cause qualitative change of the bursting attractors, resulting in several types of periodic non-smooth bursting oscillations. By employing the modified slow–fast analysis method, the mechanism of the bursting oscillations is presented upon overlapping the transformed phase and the equilibrium branches as well as their bifurcations of the generalised autonomous system. The sliding phenomenon in the bursting oscillations may occur since the governing system with different stable attractors may alternate between two subsystems located in two neighbouring regions divided by the boundary. Furthermore, the inertia of the movement along an equilibrium branch increases with the increase of the exciting amplitude, leading to the disappearance of the influence of the associated bifurcations on the attractors.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"97 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4643410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On photonic tunnelling and the possibility of superluminal transport of electromagnetic energy 光子隧穿与电磁能量超光速输运的可能性
IF 2.8 4区 物理与天体物理
Pramana Pub Date : 2023-02-15 DOI: 10.1007/s12043-022-02511-y
Luca Nanni
{"title":"On photonic tunnelling and the possibility of superluminal transport of electromagnetic energy","authors":"Luca Nanni","doi":"10.1007/s12043-022-02511-y","DOIUrl":"10.1007/s12043-022-02511-y","url":null,"abstract":"<div><p>Motivated by the increased interest in experiments in which light appears to propagate by tunnelling at superluminal velocity, the Lorentz invariant theory proposed by Partha Ghose to explain these surprising effects is revisited. This theory is based on the Harish-Chandra formalism, which describes the relativistic dynamics of a massless spin-1 boson, like a photon. By this formalism, the Bohmian average transport velocity of the electromagnetic energy is formulated. It is proved that this velocity can be superluminal if the dielectric making the waveguide is non-absorptive and non-dispersive. This result is validated in the framework of quantum electrodynamics, demonstrating that the average velocity of the photon inside the waveguide is given by the contribution of instantaneous superluminal velocities. This theory, therefore, suggests the optimal conditions for designing the optical devices capable of locally transporting electromagnetic energy at superluminal velocities mitigating signal attenuation.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"97 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12043-022-02511-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4603390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Chaotic and regular behaviours of classical and fractional Gross–Pitaevskii equations including two-body, three-body and higher-order interactions 经典和分数Gross-Pitaevskii方程的混沌和规则行为，包括二体、三体和高阶相互作用
IF 2.8 4区 物理与天体物理
Pramana Pub Date : 2023-02-09 DOI: 10.1007/s12043-022-02497-7
NESLIHAN ÜZAR
{"title":"Chaotic and regular behaviours of classical and fractional Gross–Pitaevskii equations including two-body, three-body and higher-order interactions","authors":"NESLIHAN ÜZAR","doi":"10.1007/s12043-022-02497-7","DOIUrl":"10.1007/s12043-022-02497-7","url":null,"abstract":"<div><p>This study investigates the chaotic and regular behaviours of classical and fractional Gross–Pitaevskii equations (GPE) for interacting boson systems under combined harmonic and optical lattice potentials by Poincaré section of phase space, Lyapunov exponents, power spectrum and bifurcation analysis techniques. Also, the effects of system parameters on the system behaviour are discussed. After certain values of the harmonic potential (for <span>(beta = 0.00{1})</span> and above), it is seen that the classical GP equation with two-body interaction shows shock wave-like dynamics. In addition, it is found that the harmonic potential is dominant where only binary interaction and three types of interactions exist for <span>(beta = 0.00{1})</span> and above. While the boson system exhibits a regular<span>(/)</span>quasiperiodic behaviour for a small order of fractional derivative operator, it displays a chaotic structure as it approaches the value of 2.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"97 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4383128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Spherically symmetric viscous cosmology in Brans–Dicke theory 布兰斯-迪克理论中的球对称粘性宇宙论
IF 2.8 4区 物理与天体物理
Pramana Pub Date : 2023-02-06 DOI: 10.1007/s12043-022-02495-9
S P Hatkar, G D Karhale, S D Katore
{"title":"Spherically symmetric viscous cosmology in Brans–Dicke theory","authors":"S P Hatkar,&nbsp;G D Karhale,&nbsp;S D Katore","doi":"10.1007/s12043-022-02495-9","DOIUrl":"10.1007/s12043-022-02495-9","url":null,"abstract":"<div><p>In the present paper, we investigated spherically symmetric space–time for bulk viscosity in the context of Brans–Dicke theory (BBT) of gravitation. It is observed that the Universe is accelerating for small values of expansion scalar and decelerating for large values of expansion scalar. The coefficient of bulk viscosity is negative, the wormhole is compact in Case I whereas in Case II, it is proportional to energy density and positive and the wormhole is non-compact. The required conditions for the wormhole are satisfied.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"97 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12043-022-02495-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4249569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Numerical simulation of moving boundary problem by modified Keller box method with boundary immobilisation technique 基于边界固定技术的改进Keller盒法移动边界问题的数值模拟
IF 2.8 4区 物理与天体物理
Pramana Pub Date : 2023-02-04 DOI: 10.1007/s12043-022-02506-9
V P Rabeeb Ali, Ashish Awasthi
{"title":"Numerical simulation of moving boundary problem by modified Keller box method with boundary immobilisation technique","authors":"V P Rabeeb Ali,&nbsp;Ashish Awasthi","doi":"10.1007/s12043-022-02506-9","DOIUrl":"10.1007/s12043-022-02506-9","url":null,"abstract":"<div><p>A modified Keller box (MKB) method is applied to the moving boundary problem (MBP) based on the boundary immobilisation technique. MBP is the modelling of the melting or solidification process. The mathematical importance of this problem is that the boundary of the domain is also unknown. The moving front position depends on time; hence this problem is inherently non-linear. Simulation time is used to evaluate the computational complexity of the schemes. The proposed scheme is compared to the existing schemes in the literature regarding the accuracy and simulation time. In both space and time, the proposed scheme has a second-order accuracy. For the known boundary, the constant boundary condition is taken and the proposed numerical algorithm is validated with the corresponding similarity solution. The MKB method provides good agreement with the similarity solution and also confirms that the computational rate of convergence of our scheme is two. This paper gives an idea of the MKB scheme for an MBP. This mathematical framework can be extended to 2D and 3D MBPs.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"97 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4161451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A demonstration of spectral level reconstruction of intrinsic B-mode power 本征b模功率的谱级重建演示
IF 2.8 4区 物理与天体物理
Pramana Pub Date : 2023-02-02 DOI: 10.1007/s12043-022-02509-6
Barun Kumar Pal
{"title":"A demonstration of spectral level reconstruction of intrinsic B-mode power","authors":"Barun Kumar Pal","doi":"10.1007/s12043-022-02509-6","DOIUrl":"10.1007/s12043-022-02509-6","url":null,"abstract":"<div><p>We investigate the prospects and consequences of the spectral level reconstruction of primordial <i>B</i>-mode power by solving the system of linear equation. We find that this reconstruction technique may be very useful to estimate the amplitude of primordial gravity waves or more specifically, the value of tensor-to-scalar ratio. We also see that one may have very accurate reconstruction of the intrinsic <i>B</i>-mode power up to a few hundred multipoles which is more than sufficient to estimate the tensor-to-scalar ratio. The small-scale cosmic microwave background (CMB) anisotropies are not sourced by the primordial gravity waves generated during inflation. We have also demonstrated the efficiency of our algorithm by incorporating the impact of instrumental noise considering CMB-Bharat-like futuristic space mission complemented with Planck 2018 cosmology. We shall see that spectral delensing is capable of reducing the variance in lensed CMB. We do not make any conclusive comments on this as the true non-Gaussian structure and errors in the observed CMB along with the lensing by gravity waves have been ignored.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"97 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4078395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Spin–orbit splitting of protons and neutrons 质子和中子的自旋轨道分裂
IF 2.8 4区 物理与天体物理
Pramana Pub Date : 2023-02-02 DOI: 10.1007/s12043-022-02488-8
P Mehana, N S Rajeswari
{"title":"Spin–orbit splitting of protons and neutrons","authors":"P Mehana,&nbsp;N S Rajeswari","doi":"10.1007/s12043-022-02488-8","DOIUrl":"10.1007/s12043-022-02488-8","url":null,"abstract":"<div><p>Within the framework of Yukawa-plus-exponential macroscopic model, the binding energies of magic nuclei and nuclei which are adjacent to them, are calculated using volume energy coefficient <span>(a_V)</span> and surface energy coefficient <span>(a_S)</span> as fitting parameters. Single-particle energies (SPE) are deduced for both protons and neutrons using binding energies of the core and core ± nucleon. Spin–orbit splitting of protons and neutrons are computed from the single-particle energies of protons and neutrons and compared with other literature values. SPEs calculated for the nuclei show gap for the usual proton and neutron magic numbers and new magic numbers <span>(Z, N = 14)</span> and 16. In superheavy region, a gap is noted in SPE for the proton numbers 92, 114 and neutron numbers 164 and 184. Further, the reduced spin–orbit splitting of protons and neutrons are found to possess a linear dependence on <span>(A^{-2/3})</span> and directly proportional to (<span>(ell +1/2)</span>).\u0000</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"97 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4079319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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