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We consider the simplest case of Rutherford scattering, i.e. the head-on collision, where the projectile is treated quantum mechanically. The convexity of repulsive Coulomb force invokes a disagreement between the Ehrenfest's and Hamilton's dynamics. We show that the quantum projectile cannot approach as close as the corresponding classical one, and that the average distance of closest approach depends on the position spread of the wave function describing the projectile., ICMMCMSE 2020, Alagappa University (India)

We present the quantum simulation of the deuteron to calculate its binding energy using the variational quantum eigensolver, which is based on a hybrid quantum-classical approach. Apart from a commonly used Hamiltonian derived from pionless effective field theory, we consider the interaction which can be easily studied with conventional classical methods but the corresponding operator leading to nonzero off-tridiagonal matrix elements. To map the many-body basis states on the qubit states, three encodings are explored, namely, one-hot, Bravyi-Kitaev, and the Gray code. We perform a generalized transformation for many-body operators in Gray code encoding, and simulate the Hamiltonians with nonzero off-tridiagonal matrix elements. Furthermore, the analyses of the relative efficiency of all encodings and corresponding transformations are carried out using the noise model of a real IBM quantum device. We demonstrate that the Gray code is more efficient for a large basis, irrespective of the form of potential and the presence of hardware noise.

Glitches are the observational manifestations of superfluidity inside neutron stars. The aim of this paper is to describe an automated glitch detection pipeline, which can alert the observers on possible real-time detection of rotational glitches in pulsars. Post alert, the pulsars can be monitored at a higher cadence to measure the post-glitch recovery phase. Two algorithms namely, Median Absolute Deviation (MAD) and polynomial regression have been explored to detect glitches in real time. The pipeline has been optimized with the help of simulated timing residuals for both the algorithms. Based on the simulations, we conclude that the polynomial regression algorithm is significantly more effective for real time glitch detection. The pipeline has been tested on a few published glitches. This pipeline is presently implemented at the Ooty Radio Telescope. In the era of upcoming large telescopes like SKA, several hundreds of pulsars will be observed regularly and such a tool will be useful for both real-time detection as well as optimal utilization of observation time for such glitching pulsars., 10 pages, 6 figures, Accepted for publication in MNRAS

We have interpreted the recent observation [K. Auranen et al., Phys. Lett. B 792, 187 (2019)] of proton emission from $^{108}\mathrm{I}$. We find that $\ensuremath{\gamma}$ deformation is crucial to reproduce the experimental data, and have identified the decaying state as the ${1}^{+}$ state. The effect of the residual $np$ interaction is also discussed. With the present calculation, we establish the first microscopic description of a triaxial odd-odd proton emitter.

The nonadiabatic quasiparticle approach is applied to study chiral doublet bands in $^{128}\mathrm{Cs}, ^{130}\mathrm{Cs}$, and $^{130}\mathrm{La}$. The calculated energy spectra and electromagnetic transition probabilities reproduce quite well the experimental data. $^{130}\mathrm{Cs}$ turns out to be a better example for chiral symmetry breaking than $^{128}\mathrm{Cs}$, unlike it has been suggested in earlier studies. We present the first theoretical investigation of chiral geometry and its correlation with the single-particle configurations in $^{130}\mathrm{La}$ to understand the mode of chirality, i.e., static or vibrational.

Rutherford scattering is usually described by treating the projectile either classically or as quantum mechanical plane waves. Here we treat them as wave packets and study their head-on collisions with the stationary target nuclei. We simulate the quantum dynamics of this one-dimensional system and study deviations of the average quantum solution from the classical one. These deviations are traced back to the convexity properties of Coulomb potential. Finally, we sketch how these theoretical findings could be tested in experiments looking for the onset of nuclear reactions., 16 pages, 8 figures

Rotational bands built on positive parity $$ s_{1/2} $$, $$ d_{3/2} $$, and $$ g_{7/2} $$ valence neutron orbitals in $$ ^{127}\hbox {Xe}$$ have been investigated via in-beam $$ \gamma $$ ray spectroscopy. Excited states belonging to these one-quasineutron bands were populated via $$^{122} \hbox {Sn}( ^{9} \hbox {Be}, \hbox {4n} \gamma $$) fusion-evaporation reaction at a beam energy of 48 MeV. The level scheme has been updated by extending the low-lying rotational bands up to higher spin states, as well as, by assigning the spin/parity of the constituting energy levels. Signature splitting of low-j$$ \nu s_{1/2} $$, $$ \nu d_{3/2} $$ and high-j$$ \nu g_{7/2} $$ bands have been discussed in comparison to the neighbouring nuclei. Theoretical Modified Particle Rotor Model (MPRM) calculations have been carried out in order to study the microscopic structure of these bands.

Several experimental investigations have reported evidence of collective enhancement of the nuclear level density and its fadeout. However, a suitable method is needed for experimental determination of the enhancement factor as a function of excitation energy. In this study, neutron spectra were measured in coincidence with evaporated $\ensuremath{\alpha}$ particles produced in the reactions $^{11}\mathrm{B}+^{181}\mathrm{Ta},^{197}\mathrm{Au}$. The nuclear level density parameter has been extracted for the $\mathrm{Os}\phantom{\rule{0.16em}{0ex}}(A\ensuremath{\approx}188)$ and $\mathrm{Pb}\phantom{\rule{0.16em}{0ex}}(A\ensuremath{\approx}204)$ isotopes by comparing neutron spectra with statistical model prediction. Evidence for collective enhancement has been found for Os nuclei whereas no such enhancement has been seen for Pb nuclei. The energy-dependent enhancement factor has been extracted by simultaneous fitting of the neutron spectra at various excitation energies. Near a temperature of 0.8 MeV, the enhancement starts to fadeout which is lower than the theoretically predicted temperature of 1.4 MeV for $^{187}\mathrm{Os}$. Also, free energy surface calculation shows that the $^{187}\mathrm{Os}$ nucleus undergoes a transition from collective prolate to noncollective oblate shape close to the temperature of 0.8 MeV, corroborating the early fadeout. No such shape transition is seen for $^{203}\mathrm{Pb}$.

A large wealth of data and a variety of models led to significant progress in understanding the spectra of deformed nuclei. However, a robust theoretical approach, which is less reliant on adjustable parameters is still elusive. Due to the scarcity of data, this drawback gets more pronounced while studying the exotic nuclei. With the motive to overcome this difficulty, we have developed the nonadiabatic quasiparticle approach for the description of rotational states in triaxial deformed odd–odd nuclei. The rotation-particle coupling is carried out utilizing an appropriate basis transformation such that the matrix elements of the odd–odd system can be written in terms of the rotor energies. This provides the advantage of studying the role of core more efficiently as compared to the conventional particle rotor model. The residual interaction between the valence proton and neutron is incorporated in two reliable ways, namely, the constant potential form and the zero-range interaction.

This paper reports the first observation of the Jacobi shape transition in $^{31}\mathrm{P}$ using high energy $\ensuremath{\gamma}$ rays from the decay of giant dipole resonance (GDR) as a probe. The measured GDR spectrum in the decay of $^{31}\mathrm{P}$ shows a distinct low energy component around 10 MeV, which is a clear signature of Coriolis splitting in a highly deformed rotating nucleus. Interestingly, a self-conjugate $\ensuremath{\alpha}$-cluster nucleus $^{28}\mathrm{Si}$, populated at similar initial excitation energy and angular momentum, exhibits a vastly different GDR lineshape. Even though the angular momentum of the compound nucleus $^{28}\mathrm{Si}$ is higher than the critical angular momentum required for the Jacobi shape transition, the GDR lineshape is akin to a prolate deformed nucleus. Considering the present results for $^{28}\mathrm{Si}$ and similar observation recently reported in $^{32}\mathrm{S}$, it is proposed that the nuclear orbiting phenomenon exhibited by $\ensuremath{\alpha}$-cluster nuclei hinders the Jacobi shape transition. The present experimental results suggest a possibility to investigate the nuclear orbiting phenomenon using high energy $\ensuremath{\gamma}$ rays as a probe.

We study the structure and decay properties of triaxially deformed odd-$A$ proton emitter $^{147,147\text{m}}\mathrm{Tm}$ with the modified particle-rotor model, which utilizes the microscopic nonadiabatic quasiparticle approach. In this approach the core spectrum is coupled with the particle states and hence the rotor properties are carried forward to the odd-$A$ system. We demonstrate the merits of this approach by explaining the measured rotational bands in the triaxial proton emitters $^{141}\mathrm{Ho}$ and $^{145,147}\mathrm{Tm}$. With our calculated spectra and half-lives for the proton emission, we confirm the ground state of $^{147}\mathrm{Tm}$ to be $11/{2}^{\ensuremath{-}}$ and predict the positive parity isomeric state to be $5/{2}^{+}$.

The giant dipole resonance (GDR) observables are calculated within the thermal shape fluctuation model by considering the probability distributions of different angular momentum ($I$) and temperature ($T$) values estimated recently in the deexcitation process of the compound nucleus $^{88}\mathrm{Mo}$. These results are found to be very similar to the results obtained with the average $T$ (${T}_{\mathrm{ave}}$) and average $I$ (${I}_{\mathrm{ave}}$) corresponding to those distributions. The shape transitions in $^{88}\mathrm{Mo}$ at different $T$ and $I$ are also studied through the free energy surfaces calculated within the microscopic-macroscopic approach. The deformation of $^{88}\mathrm{Mo}$ is found to increase considerably with $T$ and $I$, leading to the Jacobi shape transition at $I\ensuremath{\sim}50\phantom{\rule{0.28em}{0ex}}\ensuremath{\hbar}$. The combined effect of increasing deformation, larger fluctuations at higher $T$, and larger Coriolis splitting of GDR components at higher $I$, leads to a rapid increase in the GDR width.

Exclusive measurements of high-energy $\ensuremath{\gamma}$ rays have been performed in $^{124}\mathrm{Ba}$ and $^{136}\mathrm{Ba}$ at the same excitation energy $(\ensuremath{\sim}49\phantom{\rule{4pt}{0ex}}\mathrm{MeV})$ to study the properties of the giant dipole resonance (GDR) over a wide $N/Z$ range. The high-energy $\ensuremath{\gamma}$ rays are measured in coincidence with the multiplicity of low-energy $\ensuremath{\gamma}$ rays to disentangle the effect of temperature $(T)$ and angular momentum $(J)$. The GDR parameters are extracted employing a simulated Monte Carlo statistical model analysis. The observed $\ensuremath{\gamma}$-ray spectra of $^{124}\mathrm{Ba}$ can be explained with prolate deformation, whereas a single-component Lorentzian function which corresponds to a spherical shape could explain the $\ensuremath{\gamma}$-ray spectra of $^{136}\mathrm{Ba}$. The observed GDR width in $^{136}\mathrm{Ba}$ is narrower compared to that of $^{124}\mathrm{Ba}$. The statistical model best-fit GDR cross sections are found to be in reasonable agreement with the thermal shape fluctuation model (TSFM) calculations. Further, it is shown that the variation of GDR width with $T$ is well reproduced by the TSFM calculations over the temperature range of 1.1--1.7 MeV.

We study the role of triaxial deformation in the proton-emitting nucleus $^{109}\mathrm{I}$. We analyze the rotational spectrum as well as the decay width within the nonadiabatic quasiparticle approach. The parent nuclear wave functions are calculated using a modified rotation-particle coupling where the matrix elements of the Hamiltonian representing the rotational states of the parent nucleus are written in terms of the rotational energies of the daughter nucleus. The measured spectrum of the daughter nucleus $^{108}\mathrm{Te}$ suggests a strong role of either triaxial or vibrational degrees of freedom which is applicable for $^{109}\mathrm{I}$ also. With these results we successfully explain the spectra of the parent and daughter and also the decay width in a unified way which enables us to establish the configuration of the rotational bands and the decaying state.

We discuss the formulation of a nonadiabatic approach to study the rotational states in triaxially deformed odd-$A$ nuclei. The rotation-particle coupling is treated microscopically by coupling the triaxial rotor states of the even-even core with the states of the valence particle in order to obtain the matrix elements of the odd-$A$ system. We arrive at a nonadiabatic quasiparticle approach where the rotational states can have contributions from various quasiparticle states near the Fermi level. We bring out the advantages of this approach over the conventional particle rotor model with a fixed or variable moment of inertia. One clear evidence favoring our approach is the rotation alignment phenomenon which is demonstrated in the case of $^{137}\mathrm{Pm}$. We discuss our results for $^{136}\mathrm{Nd}$ and $^{137}\mathrm{Pm}$, and justify that this approach is suitable also for studying nuclei away from stability.

We reply to the Comment by Chakrabarty and Datar, wherein they have provided a better representation of giant dipole resonance (GDR) cross sections in $^{152}\mathrm{Gd}$, along with a revised data analysis. They have demonstrated that the results presented in our original paper calculated with higher dipole-dipole interaction strength ($\ensuremath{\eta}$) are in better agreement with the data. Consequently, both the cross sections and width could be explained with the same $\ensuremath{\eta}$, unlike in Sec. III of our original paper. However, the conclusions drawn in our original paper remain intact.

To investigate the dependence of giant dipole resonance (GDR) width on temperature $(T)$ and angular momentum $(J)$, high energy $\ensuremath{\gamma}$-ray spectra were measured in the reaction $^{28}\mathrm{Si}+^{124}\mathrm{Sn}$ at ${E}_{^{28}\mathrm{Si}}=135$ MeV. The $J$ information was deduced from multiplicity of low-energy $\ensuremath{\gamma}$ rays. The GDR parameters, namely, the centroid energy and width are extracted using statistical model analysis. The observed variation of the GDR width for $T\ensuremath{\sim}1.2$\char21{}1.37 MeV and $J\ensuremath{\sim}20\ensuremath{\hbar}$\char21{}$40\ensuremath{\hbar}$ is consistent with the universal scaling given by Kusnezov et al., which is applicable in the liquid-drop regime. The GDR input cross sections extracted from the statistical model best fits are compared with thermal shape fluctuation model (TSFM) calculations and are found to be in good agreement. The TSFM calculations predominantly favor the noncollective oblate shape, while the statistical model fit with both prolate and oblate shapes describes the data. The present data together with earlier measurements indicate a very slow variation of the GDR width for $T\ensuremath{\sim}1.2$ to 1.5 MeV. The observed trend is well explained by the TSFM calculations, although the calculated values are $\ensuremath{\sim}4$%\char21{}13% higher than the data.

Proton emission from odd-odd nuclei is studied within the two quasiparticle plus rotor model which includes the non-adiabatic effects and the residual interaction between valence proton and neutron. Justification of the formalism is discussed through corroboration of our results with the experimental spectrum of 180Ta. Exact calculations are performed to get the proton emission halflives. Our results for the proton emitter 130Eu leads to the assignment of spin and parity Jπ = 1+ for the ground state. The role of Coriolis and residual neutron-proton interactions on the proton emission halflives and their interplay are also discussed.

Working within the framework of relativistic mean field theory, we study for the first time the clustering structure (nuclear sub-structure) of 112–122 Ba nuclei in an axially deformed cylindrical coordinate. We calculate the individual neutrons and protons density distributions for Ba -isotopes. From the analysis of the clustering configurations in total (neutrons-plus-protons) density distributions for various shapes of both the ground and excited states, we find different sub-structures inside the Ba nuclei considered here. The important step, carried out here for the first time, is the counting of number of protons and neutrons present in the clustering region(s). 12 C is shown to constitute the cluster configuration in prolate-deformed ground-states of 112–116 Ba and oblate-deformed first excited states of 118–122 Ba nuclei. Presence of other lighter clusters such as 2 H , 3 H and nuclei in the neighborhood of N = Z, 14 N , 34–36 Cl , 36 Ar and 42 Ca are also indicated in the ground and excited states of these nuclei. Cases with no cluster configuration are shown for 112–116 Ba in their first and second excited states. All these results are of interest for the observed intermediate-mass-fragments and fusion–fission processes, and the so far unobserved evaporation residues from the decaying Ba * compound nuclei formed in heavy ion reactions.

The nonadiabatic quasiparticle model for triaxial shapes is used to perform calculations for decay of 141Ho, the only known odd-Z even-N deformed nucleus for which fine structure in proton emission from both ground and isomeric states was observed. All experimental data corresponding to this unique case namely, the rotational spectra of parent and daughter nuclei, decay widths and branching ratios for ground and isomeric states, could be well explained with a strong triaxial deformation γ ∼ 20 ° . The recent experimental observation of fine structure decay from the isomeric state, can be explained only with an assignment of I = 3 / 2 + as the decaying state, in contradiction with the previous assignment, of I = 1 / 2 + , based on adiabatic calculations. This study reveals that proton emission measurements could be a precise tool to probe triaxial deformations and other structural properties of exotic nuclei beyond the proton drip-line.

Clustering phenomenon in nuclei is studied within the relativistic as well as non-relativistic mean field approaches, and also as a collective clusterization process in the decaying hot compound nucleus.

We have studied the giant dipole resonance (GDR) in the hot and rotating nucleus $^{152}\mathrm{Gd}$ within the framework of the thermal shape fluctuation model (TSFM) built on the microscopic-macroscopic calculations of the free energies with a macroscopic approach for the GDR. Our results for GDR cross sections are in good agreement with the experimental values except for a component peaking around 17 MeV, where the data has large uncertainties. Such a component is beyond our description which properly takes care of the splitting of GDR components due to the deformation and Coriolis effects. Around 17 MeV lies the half maximum in experimental cross sections, and hence the extracted GDR widths and deformations (estimated from these widths) turn out to be overestimated and less reliable. Reproducing these widths with empirical formulas could conceal the information contained in the cross sections. Fully microscopic GDR calculations and a more careful look at the data could be useful to understand the GDR component around 17 MeV. We also discuss the occurrence of $\ensuremath{\gamma}$ softness in the free energy surfaces of $^{152}\mathrm{Gd}$ and its role on GDR.

Apart from the higher limits of isospin and temperature, the properties of atomic nuclei are intriguing and less explored at the limits of lowest but finite temperatures. At very low temperatures there is a strong interplay between the shell (quantal fluctuations), statistical (thermal fluctuations), and residual pairing effects as evidenced from the studies on giant dipole resonance (GDR). In our recent work [Phys. Rev. C \textbf{90}, 044308 (2014)], we have outlined some of our results from a theoretical approach for such warm nuclei where all these effects are incorporated along within the thermal shape fluctuation model (TSFM) extended to include the fluctuations in the pairing field. In this article, we present the complete formalism based on the microscopic-macroscopic approach for determining the deformation energies and a macroscopic approach which links the deformation to GDR observables. We discuss our results for the nuclei $^{97}$Tc, $^{120}$Sn, $^{179}$Au, and $^{208}$Pb, and corroborate with the experimental data available. The TSFM could explain the data successfully at low temperature only with a proper treatment of pairing and its fluctuations. More measurements with better precision could yield rich information about several phase transitions that can happen in warm nuclei., Comment: 35 pages, 12 figures, Accepted for publication in Physical Review C

We present the evolution of giant dipole resonance (GDR) width as a function of angular momentum in the compound nucleus 144 Sm in the temperature range of 1.5-2.0 MeV. The high energy γ rays emitted from the decay of excited 144 Sm were measured using large NaI detector in coincidence with 4π sum spin spectrometer. GDR widths were found to comply with thermal shape fluctuation model in this temperature range over a wide range of spin. Experimental widths tend to increase rapidly at high angular momentum values.

The reaction cross-sections are calculated for various Li, Be and B+12C systems, also involving the exotic halo nuclei, by using both the spherical and deformed relativistic mean field (RMF) densities in the finite range Glauber model with Coulomb effects included. For reactions at higher energies (>500 MeV/nucleon), both the spherical and deformed RMF densities give similar results for all the isotopic chains of exotic nuclei studied here. On the other hand, for reactions between stable nuclei, though the two RMF densities (spherical and deformed) result in simply an overall normalization for the excitation functions, it gives an improved comparison with experimental data, at high and low energies for spherical and deformed densities, respectively. A similar normalization is obtained for other densities, which means to stress that, though densities are different, they do not change much with the excitation energy. Finally, some details of the characteristic properies of exotic light nuclei are shown to contain the deformation effects of the halo nuclei.

The clustering phenomenon in superheavy nuclei is studied within the relativistic mean field approach by using the axially deformed harmonic oscillator basis. The standard BCS pairing scheme is adopted for taking the pairing interaction into account. The calculated ground and intrinsic excited state properties, and the nucleon and total matter densities, as well as the proton–neutron asymmetry distributions, are analysed to look for cluster configurations and/or exotic clusters in superheavy nuclei. We have applied our method to Z = 120, N = 172–184 nuclei. A new 'bubble'-like structure for the Z = 120, N = 172, 292120 nucleus as signatures of doubly closed shells and a two-cluster configuration for the Z = 120, N = 184, 304120 nucleus are some of the interesting results obtained. New possibilities of exotic clusters at the centre of superheavy nuclei are also indicated.

We discuss the shape transitions in few medium heavy-mass nuclei with emphasis on low-temperature behaviour of the giant dipole resonance (GDR) observables. We employ a macroscopic approach towards GDR in which the GDR observables are related to the nuclear shapes. Shape calculations were done using the cranked Nilsson-Strutinsky method (CNSM) extended to finite temperature. Thermal shape fluctuations are computed with free energies calculated employing Landau parameterization as well as those calculated exactly (without using parameterizations) at given spin and temperature. The results obtained are confronted with the experimental data wherever available. Our study reveals that if the fluctuations are treated properly, then, in spite of thermal fluctuations, GDR observables could very well reflect the shape transitions at low temperature.

We investigate how well the shape parameterizations are applicable for studying the giant dipole resonance (GDR) in nuclei, in the low temperature and/or high spin regime. The shape fluctuations due to thermal effects in the GDR observables are calculated using the actual free energies evaluated at fixed spin and temperature. The results obtained are compared with Landau theory calculations done by parameterizing the free energy. We exemplify that the Landau theory could be inadequate where shell effects are dominating. This discrepancy at low temperatures and high spins are well reflected in GDR observables and hence insists on exact calculations in such cases., 10 pages, 2 figures

We analyze the results for infinite nuclear and neutron matter using the standard relativistic mean field model and its recent effective field theory motivated generalization. For the first time, we show quantitatively that the inclusion in the effective theory of vector meson self-interactions and scalar-vector cross-interactions explains naturally the recent experimental observations of the softness of the nuclear equation of state, without losing the advantages of the standard relativistic model for finite nuclei., 8 pages, 1 figure, REVTeX

We have investigated the ground-state structures of even-even Hf, W and Os isotopes within the framework of a deformed non-relativistic Hartree-Fock and a relativistic mean field formalism. A majority of the nuclei are predicted to be prolate in shape in the relativistic calculations. On the other hand, contrary to the relativistic results, we predict a shape change in a cyclic order in the non-relativistic calculations. However, in both the cases, the magnitude of the quadrupole deformation parameter agrees well with the experimental data. We also evaluated the hexadecapole deformation parameter for Hf, W and Os isotopes and irrespective of the shape change in quadrupole moments, we find a cyclic change in hexadecapole shape from positive to negative and vice versa in both the relativistic and non-relativistic formalisms.

The low-lying rotational bands of triaxially deformed nuclei 137Pr, 137Pm and 139Eu are studied with a modified particle-rotor model following the nonadiabatic quasiparticle approach. The matrix elements of the odd-A nucleus are obtained in terms of a coupling matrix and the rotational energies of the even–even core. The spectra of the cores 136Ce, 136Nd and 138Sm indicate a strong influence of triaxial deformation and vibrational degrees of freedom. These properties are appropriately carried forward to the calculations for the odd-A nucleus. We demonstrate that the ground and side bands of the odd-A nucleus and its core can be explained with the same set of deformation parameters (, γ). We argue that this method could be useful in studying the low-lying states in exotic nuclei also.

We present an approach that includes temperature-dependent shell effects and fluctuations of the pairing field in the thermal shape fluctuation model (TSFM). We apply this approach to study the width of giant dipole resonance (GDR) in $^{97}$Tc, $^{120}$Sn and $^{208}$Pb. Our results demonstrate that the TSFM that includes pairing fluctuations can explain the recently observed quenching in the GDR width. We also show that to validate pairing prescriptions and the parameters involved, we require more and precise data., Comment: Accepted for publication in Physical Review C

We discuss the non-adiabatic quasiparticle approach for calculating the rotational spectra and decay width of odd-odd proton emitters. The Coriolis effects are incorporated in both the parent and daughter wave functions. Results for the two probable ground states (1+ and 2+ ) of the proton emitter 130 Eu are discussed. With our calculations, we confirm the proton emitting state to be the Iπ = 1+ state, irrespective of the strength of the Coriolis interaction. This study provides us with an opportunity to look into the details of wave functions of deformed odd-odd nuclei to which the proton emission halflives are quite sensitive.

Landau theory used for studying hot rotating nuclei usually uses zero temperature Strutinsky smoothed total energy for the temperature dependent shell corrections. This is replaced in this work by the temperature dependent Strutinsky smoothed free energy. Our results show that this replacement has only marginal effect for temperatures greater than 1 MeV but plays significant role at lower temperatures.

High spin states of 72,73,74Se nuclei are discussed using calculations from the cranked Nilsson Strutinsky method with tuning to fixed spins. The low spin anomaly in the yrast bands of these nuclei is interpreted in a rotational co-existence picture. High K rotational isomers are proposed for I π =4+ in 72Se and 6+ in 74Se.

Proton emission from deformed nuclei near the drip line is regarded as a versatile tool in nuclear structure physics and such a study in odd-odd nuclei provides us with an excellent opportunity to understand several interesting features including the interaction between the valence proton and the valence neutron. We present a detailed formalism for a full microscopic calculation of such proton emitters, where the nuclear structure and decay aspects are taken into account exactly. This formalism is based on the nonadiabatic approach for the two quasiparticle plus rotor model, where the residual neutron-proton interactions are considered in the mean field represented by a deformed Woods-Saxon potential. We demonstrate a systematic way of unambiguously identifying several parameters involved in the calculations with the aid of the experimental data. The quality of results in the case of ${}^{180}$Ta justifies the approach which is further extended to discuss in detail the proton emission from ${}^{130}$Eu. ${I}^{\ensuremath{\pi}}={1}^{+}$ state in ${}^{130}$Eu still remains to be the proton emitting state irrespective of the choice of several parameters. We also note that the decay widths could be quite sensitive to the residual $np$ interaction in case of proton emission from isomeric states.

Extending the relativistic mean field (RMF) models either with higher order couplings or with density-dependent couplings has been proven to be successful in explaining several properties of finite nuclei, infinite matter, and neutron stars (NSs) in a unified way. Here, we compare how these two extensions fare while explaining NSs with and without antikaons. Both these extensions soften the equation of state (EoS), but the higher order couplings are more efficient in doing so. Even for a very soft EoS, we find that there is a strong possibility of antikaons being condensed. We find an exception for correlation between NS radius and density dependence of symmetry energy, which gets restored when we introduce antikaons. The implication of a precisely measured 2${M}_{\ensuremath{\bigodot}}$ NS on our results is discussed with four sets of interactions which cover all four combinations of stiff and soft symmetry energy and equations of state.

To explain several properties of finite nuclei, infinite matter, and neutron stars in a unified way within the relativistic mean field models, it is important to extend them either with higher order couplings or with density-dependent couplings. These extensions are known to have strong impact in the high-density regime. Here we explore their role on the equation of state at densities lower than the saturation density of finite nuclei which govern the phase transitions associated with pasta structures in the crust of neutron stars., Accepted in Phys Rev. C 2013

We investigate the role of higher order couplings, along with the condensation of antikaons ($K^-$ and $\bar K^0$), on the properties of neutron star (NS). We employ extended versions of the relativistic mean-field model, in which kaon-nucleon and nucleon-nucleon interactions are taken on the same footing. We find that the onset of condensation of $K^-$ and $\bar K^0$ highly depends not only on the strength of optical potential but also on the new couplings. The presence of antikaons leads to a softer equation of state and makes the neutron star core symmetric and lepton-deficient. We show that these effects strongly influence the mass-radius relation as well as the composition of neutron star. We also show that the recently observed 1.97$\pm$.04 solar mass NS can be explained in three ways: (i) a stiffer EoS with both antikaons, (ii) a relatively soft EoS with $K^-$ and (iii) a softer EoS without antikaons.

We present for the first time, the non-adiabatic quasiparticle approach to study proton emission from odd–odd deformed nuclei which includes the residual neutron–proton interaction. We perform exact calculations of decay widths for the proton emission from 130 Eu where the Coriolis effects are included in both the parent and daughter wavefunctions. Without assuming an exact Nilsson state from where the decay could happen, we could explain the experimentally observed half-life. We discuss the interplay between the Coriolis and the residual np interaction as well. This is significant because whereas most of the studies on odd–odd nuclei concern only the energies, a description of decay can test the details of the wavefunctions which may be strongly influenced by the residual interaction.

We extend the effective field theory motivated relativistic mean field (ERMF) model with the inclusion of K−-meson and Λ-hyperon and compare the nucleon (N), nucleon-kaon (NK), nucleon-Λ (NΛ), nucleon-kaon-Λ (NKΛ) phases in neutron star (NS) matter. We analyze different properties such as nucleon, kaon and Λ effective masses, the mass-radius relations of NS and the composition of NS in the presence of K− and Λ. We find that these exotic particles can strongly influence the properties of NS, even in the presence of higher order couplings of the ERMF model.

We discuss the role of higher order couplings in conjunction with kaon condensation using recent versions of relativistic mean field models.We focus on an interaction (G2) in which all the parameters are obtained by fitting the finite nuclear data and successfully applied to reproduce a variety of nuclear properties. Our results show that the higher order couplings play a significant role at higher densities where kaons dominate the behavior of the equation of state. We compare our results with other interactions (NLl, NL3, G1, and FSUGold) and show that the new couplings bring down the mass of a neutron star (NS), which is further reduced in the presence of kaons to yield results consistent with the present observational constraints. We show that the composition of the NS varies with the parameter sets., 10 pages, 11 figures

We review the role of antikaons in recent versions of relativistic mean field models and focus on the interactions in which all parameters are obtained by fitting finite nuclear data and successfully applied to reproduce a variety of nuclear and neutron star (NS) properties. We show that the recently observed 1.97 solar mass NS can be explained in three ways: (i) A stiffer EoS with both antikaons (K−, K0), (ii) a relatively softer EoS with K− and (iii) a softer EoS with nucleon phase only.