Browsing by Author "M. Kumar Raju"

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Candidates for twin chiral bands in Rh 102
(2014) D. Tonev; M.S. Yavahchova; N. Goutev; G. De Angelis; P. Petkov; R.K. Bhowmik; R.P. Singh; S. Muralithar; N. Madhavan; R. Kumar; M. Kumar Raju; J. Kaur; G. Mohanto; A. Singh; N. Kaur; R. Garg; A. Shukla; Ts. K. Marinov; S. Brant
Excited states in Rh102, populated in the fusion-evaporation reaction Zr94(B11,3n)Rh102 at a beam energy of 36 MeV, were studied using the Indian National Gamma Array spectrometer at Inter University Accelerator Center, New Delhi. The angular correlations and the electromagnetic character of some of the gamma-ray transitions observed were investigated in detail. A new chiral candidate sister band was found. Lifetimes of exited states in both chiral candidate bands of Rh102 were measured for the first time in the A∼100 mass region by means of the Doppler-shift attenuation technique. The derived reduced transition probabilities are compared to the predictions of the two quasiparticles plus triaxial rotor model. Both experimental results and calculations do not support the presence of static chirality in Rh102. © 2014 American Physical Society.
Check for chirality in 102Rh
(2012) D. Tonev; N. Goutev; M.S. Yavahchova; P. Petkov; G. De Angelis; R.K. Bhowmik; R.P. Singh; S. Muralithar; N. Madhavan; R. Kumar; M. Kumar Raju; J. Kaur; G. Mahanto; A. Singh; N. Kaur; R. Garg; A. Sukla; Ts.K. Marinov; S. Brant
Excited states in 102Rh, populated by the fusion-evaporation reaction 94Zr(11B,3n)102Rh at a beam energy of 36 MeV, were studied using the INGA spectrometer at IUAC, New Delhi. The angular correlations and the electromagnetic character of some of the gamma-ray transitions observed were investigated in details. A new chiral candidate sister band was found in the level-scheme of 102Rh. Lifetimes of exited states in 102Rh were measured by means of the Doppler-shift attenuation technique. The experimental results do not support the presence of static chirality in 102Rh. © 2012 American Institute of Physics.
Does chirality exist in nuclei? The case of 102Rh
(Bulgarian Academy of Sciences, 2015) M.S. Yavahchova; D. Tonev; N. Goutev; G. De Angelis; P. Petkov; R.K. Bhowmik; R.P. Singh; S. Muralithar; N. Madhavan; R. Kumar; M. Kumar Raju; J. Kaur; G. Mohanto; A. Singh; N. Kaur; R. Garg; A. Sukla; Ts.K. Marinov; S. Brant
Excited states in 102Rh, populated in the fusion-evaporation reaction 94Zr(11B, 3n)102Rh at a beam energy of 36 MeV, were studied using the INGA spectrometer at IUAC, New Delhi. A new chiral candidate sister band was found. Lifetimes of exited states in 102Rh were measured for the first time by means of the Doppler-shift attenuation technique. A new band was found in the level-scheme of 102Rh. 1 band with a negative parity.
Dynamic chirality in mass regions A=105 and A=130
(Institute of Physics Publishing, 2018) M.S. Yavahchova; D. Tonev; G. De Angelis; P. Petkov; N. Goutev; R.K. Bhowmik; R.P. Singh; S. Muralithar; N. Madhavan; R. Kumar; M. Kumar Raju; J. Kaur; G. Mohanto; A. Singh; N. Kaur; R. Garg; A. Shukla; R. Mateva; E. Geleva; B. Slavchev; S. Brant
Chiral symmetry is dichotomic and its spontaneous breaking by the axial angular momentum vector leads to a pair of degenerate ΔI = 1 rotational bands, called chiral doublet bands. In many cases the energy degeneracy of the chiral candidate bands has almost been observed but the transition probabilities of the analogue states have been found to be different. In the angular momentum region where chirality sets in the B(E2) values of the electromagnetic transitions deexciting analogue states of the chiral twin bands should be almost equal. Correspondingly the B(M1) values should exhibit staggering. Experimental data for two nuclei from different mass regions are compared with theoretical predictions. Exited states in 134Pr were populated in the fusion-evaporation reaction 119Sn(19F, 4n)134Pr, while excited states in 102Rh were populated in the fusion-evaporation reaction 94Zr(11B, 3n)102Rh. Our lifetime measurements and level-scheme investigations show that there are similarities in both chiral candidates nuclei related to dynamic chirality. © Published under licence by IOP Publishing Ltd.
Evolution of collectivity and evidence of octupole correlations in Br 73
(American Physical Society, 2019) S. Bhattacharya; T. Trivedi; D. Negi; R.P. Singh; S. Muralithar; R. Palit; I. Ragnarsson; S. Nag; S. Rajbanshi; M. Kumar Raju; V.V. Parkar; G. Mohanto; S. Kumar; D. Choudhury; R. Kumar; R.K. Bhowmik; S.C. Pancholi; A.K. Jain
High-spin states in the Br73 nucleus have been populated via the Cr50(Si28,αp)Br73 fusion evaporation reaction with a beam energy of 90 MeV. The deexciting gamma rays were detected using the Indian National Gamma Array (INGA). Using the γ-γ coincidence technique, two new bands and eight new interconnecting transitions have been added. The strong interconnecting E1 transitions, between positive and negative parity bands, ensure the existence of octupole correlations at low spin. Line shapes have been observed for 17 transitions, which were analyzed by the Doppler-shift attenuation method to determine the lifetime of excited states of the yrast negative parity band and its signature partner band along with the positive parity band. The deduced transitional quadrupole moments Qt for the ground state band decrease with increasing spin, with their values ranging from 2.88 to 1.00 eb. A similar trend in the quadrupole moment has also been observed for the signature partner as well as for the positive parity band. This decrease in Qt with increasing spin for these bands is interpreted in terms of the cranked Nilsson-Strutinsky model and total Routhian surface calculations, which indicate possible band termination at higher spin. © 2019 American Physical Society.
Examples of dynamic chirality in nuclei
(EDP Sciences, 2018) M.S. Yavahchova; D. Tonev; N. Goutev; G. De Angelis; R.K. Bhowmik; R.P. Singh; S. Muralithar; N. Madhavan; R. Kumar; M. Kumar Raju; J. Kaur; G. Mahanto; A. Singh; N. Kaur; R. Garg; A. Sukla
In many cases the chirality was almost observed but the transition probabilities are different. This fact is clearly seen in the cases of 134Pr and 102Rh. In the case of chirality, the yrast and the side bands should be nearly degenerate. In the angular momentum region where chirality sets, the B(E2) values of the electromagnetic transitions deexciting analog states of the chiral twin bands should be almost equal. Correspondingly the B(M1) values should exhibit staggering. Our lifetime measurements in the cases of 134Pr and 102Rh and the theoretical analysis do not support static chirality. Chirality has mainly a dynamical character in both nuclei. In the present paper, we compare our results with the results for other chiral candidate nuclei, which fulfill static chirality conditions. © The Authors, published by EDP Sciences, 2018.
High spin structure in 130,131Ba
(Springer New York LLC, 2014) Navneet Kaur; A. Kumar; G. Mukherjee; Amandeep Singh; S. Kumar; Rajbir Kaur; Varinderjit Singh; B.R. Behera; K.P. Singh; G. Singh; H.P. Sharma; Suresh Kumar; M. Kumar Raju; P.V. Madhusudhan Rao; S. Muralithar; R.P. Singh; Rakesh Kumar; N. Madhvan; R.K. Bhowmik
High spin states of, 130,131Ba have been investigated via fusion evaporation reactions 122Sn (13C,4n)131Ba and 122Sn(13C, 5n)130Ba at Ebeam = 65MeV. The level schemes of 130,131Ba have been extended by placing several new γ transitions. A few interband transitions connecting two negative-parity bands, which are the experimental fingerprints of signature partners, have been established in 130Ba. Spin and parity of a side band have been assigned in 131Ba and this dipole band is proposed to have a three-quasiparticle configuration, vh11/2 ⊗ πh11/2⊗ πg7/2. The observed band structures and nuclear shape evolution as a function of the angular momentum have been discussed in the light of Total-Routhian-Surface calculations. © Società Italiana di Fisica/Springer-Verlag 2014.
In a search for a chiral symmetry in 102Rh
(Institute of Physics Publishing, 2014) M.S. Yavahchova; D. Tonev; N. Goutev; P. Petkov; G. De Angelis; R.K. Bhowmik; R.P. Singh; S. Muralithar; N. Madhavan; R. Kumar; M. Kumar Raju; J. Kaur; G. Mohanto; A. Singh; N. Kaur; R. Garg; A. Sukla; Ts K. Marinov; S. Brant
Excited states in 102Rh were populated in the fusion-evaporation reaction 94Zr(nB, 3n)102Rh at a beam energy of 36 MeV, using the INGA spectrometer at IUAC, New Delhi. The angular correlations and the electromagnetic character of some of the γ-ray transitions observed in 102Rh were investigated in detail. A new candidate for a chiral twin band was identified in 102Rh for the first time.
Investigation of chirality in the case of 102Rh
(Institute of Physics Publishing, 2016) M.S. Yavahchova; D. Tonev; N. Goutev; G. De Angelis; P. Petkov; R.K. Bhowmik; R.P. Singh; S. Muralithar; N. Madhavan; R. Kumar; M. Kumar Raju; J. Kaur; G. Mahanto; A. Singh; N. Kaur; R. Garg; A. Sukla; Ts. K. Marinov; R.R. Mateeva; S. Brant
Excited states in 102Rh were populated in the fusion-evaporation reaction 94Zr(11B, 3n)102Rh at a beam energy of 36 MeV using the INGA spectrometer at IUAC, New Delhi. The angular correlations and the electromagnetic character of some of the gamma-ray transitions observed were investigated in details. A new chiral candidate sister band was found. Lifetimes of exited states in 102Rh were measured using the Doppler-shift attenuation technique and the derived reduced transition probabilities are compared to the predictions of the Two Quasiparticles Plus Triaxial Rotor model. © Published under licence by IOP Publishing Ltd.
Level scheme investigation of 102Rh
(Institute of Physics Publishing, 2012) N. Goutev; M.S. Yavahchova; D. Tonev; G. De Angelis; P. Petkov; R.K. Bhowmik; R.P. Singh; S. Muralithar; N. Madhavan; R. Kumar; M. Kumar Raju; J. Kaur; G. Mahanto; A. Singh; N. Kaur; R. Garg; A. Sukla; Ts.K. Marinov; S. Brant
Excited states in102Rh were populated in the fusion-evaporation reaction 96Zr(11B, 3n)102 Rh. The angular correlations and the electromagnetic character of some of the gamma-ray transitions observed were investigated in detail. A new chiral candidate sister band was found in the level-scheme of 102Rh.
Lifetime measurements in mass regions A=100 and A=130 as a test for chirality in nuclear systems
(EDP Sciences, 2016) D. Tonev; M.S. Yavahchova; G. De Angelis; S. Brant; S. Frauendorf; P. Petkov; A. Dewald; Q. Zhong; D. Curien; N. Goutev; R.K. Bhowmik; R.P. Singh; S. Muralithar; N. Madhavan; R. Kumar; M. Kumar Raju; J. Kaur; G. Mahanto; A. Singh; N. Kaur; R. Garg; A. Sukla; E. Geleva; Ts. K. Marinov
Two odd-odd nuclei from the A ∼ 100 and A ∼ 130 regions, namely 102Rh and 134Pr have been studied in search for chiral doublet bands via 94Zr(11B,3n)102Rh and 119Sn(19F,4n)134Pr reactions, respectively. Two nearly degenerate bands built on the πg9/2 ⊗ νh11/2 configuration have been identified in 102Rh and on the πg11/2 ⊗ νh11/2 configuration for 134Pr. Lifetimes of excited nuclear states were measured using Dopplershift attenuation method and recoil distance Doppler-shift method. The deexciting gamma rays were registered by the Indian National Gamma Array for 102Rh and using the EUROBALL IV detector array with an inner Bismuth Germanate (BGO) ball for 134Pr, respectively. Polarization and angular correlation measurements have been performed to establish the spin and parity assignments for these bands. The derived reduced transition probabilities are compared to the predicitons of the two quasiparticles + triaxial rotor and interacting boson fermion-fermion models. © 2016 Owned by the authors, published by EDP Sciences.
Spectroscopy of the odd-odd chiral candidate nucleus 102Rh
(2014) M.S. Yavahchova; N. Goutev; D. Tonev; G. De Angelis; R.K. Bhowmik; P. Petkov; R.P. Singh; S. Muralithar; N. Madhavan; R. Kumar; M. Kumar Raju; J. Kaur; G. Mohanto; A. Singh; N. Kaur; A. Sukla; S. Brant; R. Garg; Ts.K. Marinov
Excited states in 102Rh were populated in the fusion-evaporation reaction 94Zr(11B, 3n)102Rh at a beam energy of 36 MeV, using the INGA spectrometer at IUAC, New Delhi. The angular correlations and the electromagnetic character of some of the 03B3-ray transitions observed in 102Rh were investigated in detail. A new candidate for achiral twin band was identified in 102Rh for the first time. © Owned by the authors, published by EDP Sciences, 2014.