Nuclear and High Energy Physics, Nuclear and High Energy Physics
7
Scopus Publications
61
Scholar Citations
4
Scholar h-index
3
Scholar i10-index
Scopus Publications
Indispensability of cross-shell contributions in neutron resonance spacing T Ghosh, Sangeeta, B Maheshwari, G Saxena, B K Agrawal Journal of Physics G Nuclear and Particle Physics, 2024 Spin- and parity-dependent nuclear level densities (NLDs) are obtained for a configuration interaction shell model using a numerically efficient spectral distribution method. The calculations are performed for 24Na and 25,26,27Mg nuclei using full sd-pf model space that incorporates the cross-shell excitations from the sd to the pf-shell. The obtained NLDs are then employed to determine the s-wave neutron resonance spacing (D0), which is one of the crucial inputs for the predictions of astrophysical reaction rates. Although the considered nuclei are not neutron-rich, the contributions from cross-shell excitations to the pf-shell are indispensable for explaining the experimental data for D0, which otherwise are significantly overestimated.
Astrophysical reaction rates with realistic nuclear level densities Sangeeta, T. Ghosh, B. Maheshwari, G. Saxena, B. K. Agrawal Physical Review C, 2022 Realistic nuclear level densities (NLDs) obtained within the spectral distribution method (SDM) are employed to study nuclear processes of astrophysical interest. The merit of SDM lies in the fact that the NLDs corresponding to many-body shell-model Hamiltonians consisting of residual interaction can be obtained for the full configurational space without recourse to the exact diagnolization of huge matrices. We calculate NLDs and $s$-wave neutron resonance spacings which agree reasonably well with the available experimental data. By employing these NLDs, we compute reaction cross sections and astrophysical reaction rates for radiative neutron capture in few Fe-group nuclei and compare them with experimental data as well as with those obtained with NLDs from phenomenological and microscopic mean-field models. The results obtained for the NLDs from SDM are able to explain the experimental data quite well. These results are of particular importance since the configuration mixing through the residual interaction naturally accounts for the collective excitations. In the mean-field models, the collective effects are included through the vibrational and rotational enhancement factors, and their NLDs are further normalized at low energies with neutron resonance data.
Nuclear level densities away from line of β-stability T Ghosh, B Maheshwari, Sangeeta, G Saxena, B K Agrawal Journal of Physics G Nuclear and Particle Physics, 2022 The variation of total nuclear level densities (NLDs) and level density parameters with proton number ( Z ) are studied around the β -stable isotope, Z 0 , for a given mass number. We perform our analysis for a mass range A = 40 to 180 using the NLDs from popularly used databases obtained with the single-particle energies from two different microscopic mass-models. These NLDs which include microscopic structural effects such as collective enhancement, pairing and shell corrections, do not exhibit inverted parabolic trend with a strong peak at Z 0 as predicted earlier. We also compute the NLDs using the single-particle energies from macroscopic–microscopic mass-model. Once the collective and pairing effects are ignored, the inverted parabolic trends of NLDs and the corresponding level density parameters become somewhat visible. Nevertheless, the factor that governs the ( Z − Z 0 ) dependence of the level density parameter, leading to the inverted parabolic trend, is found to be smaller by an order of magnitude. We further find that the ( Z − Z 0 ) dependence of NLDs is quite sensitive to the shell effects.
Collective enhancement in nuclear level density G. Mohanto, A. Parihari, P. C. Rout, S. De, E. T. Mirgule, B. Srinivasan, K. Mahata, S. P. Behera, M. Kushwaha, D. Sarkar, B. K. Nayak, A. Saxena, A. K. Rhine Kumar, A. Gandhi, Sangeeta, Nabendu K. Deb, P. Arumugam Physical Review C, 2019 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 $^{203}\mathrm{Pb}$.
Sensitivity of the transition energy towards mass asymmetry of the colliding nuclei Anupriya Jain, Sangeeta Arora, Suneel Kumar EPJ Web of Conferences, 2014 We investigate the role of the mass asymmetry on the transition energy by studying asymmetric reactions using the isospin dependent quantum molecular dynamics (IQMD) model. Substantial and the uniform effect of the asymmetry of the reaction has been observed on the transition energy. Moreover, isospin effects shows a small influence on the mass asymmetry (η) dependence of transition energy.
Indispensability of cross-shell contributions in neutron resonance spacing T Ghosh, Sangeeta, B Maheshwari, G Saxena, BK Agrawal Journal of Physics G: Nuclear and Particle Physics 51 (4), 045105 , 2024 2024
Investigation of 58 Ni (n, p) 58 Co reaction cross-section with covariance analysis A Hingu, S Mukherjee, S Parashari, A Sangeeta, A Gandhi, M Upadhyay, ... Chinese Physics C 48 (2), 024001 , 2024 2024 Citations: 10
Impact of density dependence of symmetry energy on astrophysical S -factor for heavy-ion fusion reactions T Ghosh, Sangeeta, G Saxena, BK Agrawal, U Datta The European Physical Journal A 59 (11), 266 , 2023 2023 Citations: 4
Onset of pressure gradient on collective flow through balance and transition geometry Sangeeta, V Kaur EPJ Web of Conferences 279, 11017 , 2023 2023
Astrophysical reaction rates with realistic nuclear level densities Sangeeta, T Ghosh, B Maheshwari, G Saxena, BK Agrawal Physical Review C 105 (4), 044320 , 2022 2022 Citations: 10
Nuclear level densities away from line of β -stability T Ghosh, B Maheshwari, Sangeeta, G Saxena, BK Agrawal Journal of Physics G: Nuclear and Particle Physics 49 (2), 025103 , 2022 2022
Effect of nuclear structure and fissility on quasifission G Mohanto, S De, A Parihari, PC Rout, K Ramachandran, K Mahata, ... Physical Review C 102 (4), 044610 , 2020 2020 Citations: 3
Effect of clusterization algorithm with isospin-dependent nuclear charge radii parameterization on azimuthal angle dependence of elliptical flow. V Kaur Indian Journal of Pure & Applied Physics 57 (9) , 2019 2019
Collective enhancement in nuclear level density G Mohanto, A Parihari, PC Rout, S De, ET Mirgule, B Srinivasan, ... PHYSICAL REVIEW C Phys Rev C 100 (011602), 011602 , 2019 2019 Citations: 22
Structural and isospin effects on balance energy and transition energy via different nuclear charge radii parameterizations V Kaur Nuclear Physics A 966, 20-33 , 2017 2017 Citations: 1
Role of different nuclear charge radii parameterizations on the thermal equilibrium in nuclear reaction Sangeeta, V Kaur EPJ Web of Conferences 146, 12017 , 2017 2017
Structural Effects Through Nuclear Charge Radius in Mass Asymmetric Collisions V Kaur Acta Physica Polonica B 48 (3), 623 , 2017 2017 Citations: 2
Influence of Nuclear Charge Radius Parameterization on the Excitation Function of Nuclear Stopping SV Kaur Indian Journal of Science and Technology 10 (31), 1-5 , 2017 2017
INITIALIZATION EFFECTS VIA NUCLEAR CHARGE RADII PARAMETERIZATIONS ON THE NUCLEAR STOPPING AND ITS RELATION TO DISTRIBUTION AND PRODUCTION OF LIGHT MASS FRAGMENTS Sangeeta ACTA PHYSICA POLONICA B 47 (3), 991-996 , 2016 2016 Citations: 2
Influence of isospin dependent nuclear charge radii on fragmentation in heavy ion collisions A Jain, S Kumar Nuclear Physics A 927, 220-231 , 2014 2014 Citations: 7
Sensitivity of the transition energy towards mass asymmetry of the colliding nuclei A Jain, S Arora, S Kumar EPJ Web of Conferences 66, 03039 , 2014 2014
MOST CITED SCHOLAR PUBLICATIONS
Collective enhancement in nuclear level density G Mohanto, A Parihari, PC Rout, S De, ET Mirgule, B Srinivasan, ... PHYSICAL REVIEW C Phys Rev C 100 (011602), 011602 , 2019 2019 Citations: 22
Investigation of 58 Ni (n, p) 58 Co reaction cross-section with covariance analysis A Hingu, S Mukherjee, S Parashari, A Sangeeta, A Gandhi, M Upadhyay, ... Chinese Physics C 48 (2), 024001 , 2024 2024 Citations: 10
Astrophysical reaction rates with realistic nuclear level densities Sangeeta, T Ghosh, B Maheshwari, G Saxena, BK Agrawal Physical Review C 105 (4), 044320 , 2022 2022 Citations: 10
Influence of isospin dependent nuclear charge radii on fragmentation in heavy ion collisions A Jain, S Kumar Nuclear Physics A 927, 220-231 , 2014 2014 Citations: 7
Impact of density dependence of symmetry energy on astrophysical S -factor for heavy-ion fusion reactions T Ghosh, Sangeeta, G Saxena, BK Agrawal, U Datta The European Physical Journal A 59 (11), 266 , 2023 2023 Citations: 4
Effect of nuclear structure and fissility on quasifission G Mohanto, S De, A Parihari, PC Rout, K Ramachandran, K Mahata, ... Physical Review C 102 (4), 044610 , 2020 2020 Citations: 3
Structural Effects Through Nuclear Charge Radius in Mass Asymmetric Collisions V Kaur Acta Physica Polonica B 48 (3), 623 , 2017 2017 Citations: 2
INITIALIZATION EFFECTS VIA NUCLEAR CHARGE RADII PARAMETERIZATIONS ON THE NUCLEAR STOPPING AND ITS RELATION TO DISTRIBUTION AND PRODUCTION OF LIGHT MASS FRAGMENTS Sangeeta ACTA PHYSICA POLONICA B 47 (3), 991-996 , 2016 2016 Citations: 2
Structural and isospin effects on balance energy and transition energy via different nuclear charge radii parameterizations V Kaur Nuclear Physics A 966, 20-33 , 2017 2017 Citations: 1
Indispensability of cross-shell contributions in neutron resonance spacing T Ghosh, Sangeeta, B Maheshwari, G Saxena, BK Agrawal Journal of Physics G: Nuclear and Particle Physics 51 (4), 045105 , 2024 2024
Onset of pressure gradient on collective flow through balance and transition geometry Sangeeta, V Kaur EPJ Web of Conferences 279, 11017 , 2023 2023
Nuclear level densities away from line of β -stability T Ghosh, B Maheshwari, Sangeeta, G Saxena, BK Agrawal Journal of Physics G: Nuclear and Particle Physics 49 (2), 025103 , 2022 2022
Effect of clusterization algorithm with isospin-dependent nuclear charge radii parameterization on azimuthal angle dependence of elliptical flow. V Kaur Indian Journal of Pure & Applied Physics 57 (9) , 2019 2019
Role of different nuclear charge radii parameterizations on the thermal equilibrium in nuclear reaction Sangeeta, V Kaur EPJ Web of Conferences 146, 12017 , 2017 2017
Influence of Nuclear Charge Radius Parameterization on the Excitation Function of Nuclear Stopping SV Kaur Indian Journal of Science and Technology 10 (31), 1-5 , 2017 2017
Sensitivity of the transition energy towards mass asymmetry of the colliding nuclei A Jain, S Arora, S Kumar EPJ Web of Conferences 66, 03039 , 2014 2014
