Search

Your search keyword '"Srivastava, P.C."' showing total 271 results
Start Over Author "Srivastava, P.C."
271 results on '"Srivastava, P.C."'

11. Three-phonon multiplets in 116Sn

Author

Ray, Prithwijita, Pai, H., Ali, Sajad, Mukherjee, A., Rajbanshi, S., Chakraborty, S., Bhattacharya, Soumik, Banik, R., Nandi, S., Bhattacharyya, S., Mukherjee, G., Bhattacharya, C., Gangopadhyay, G., Samanta, S., Das, S., Chatterjee, S., Raut, R., Ghugre, S.S., Srivastava, P.C., Jehangir, S., Bhoy, Bharti, Rather, N., Bhat, G.H., Sheikh, J.A., and Goswami, A.

Published
2022
Full Text
View/download PDF

28. Beta Decay Study of the [formula omitted]56Zn Nucleus and the Determination of the Half-Lives of a Few fp-shell Nuclei

Author

Rubio, B., Orrigo, S.E.A., Kucuk, L., Montaner-Pizá, A., Fujita, Y., Fujita, H., Blank, B., Gelletly, W., Adachi, T., Agramunt, J., Algora, A., Ascher, P., Bilgier, B., Cáceres, L., Cakirli, R.B., de France, G., Ganioğlu, E., Gerbaux, M., Giovinazzo, J., Grevy, S., Kamalou, O., Kozer, H.C., Kurtukian-Nieto, T., Marqués, F.M., Molina, F., Oktem, Y., de Oliveira Santos, F., Perrot, L., Popescu, L., Raabe, R., Rogers, A.M., Srivastava, P.C., Susoy, G., Suzuki, T., Tamii, A., and Thomas, J.C.

Published
2014
Full Text
View/download PDF

32. Emergence of an island of extreme nuclear isomerism at high excitation near Pb

Author

Wahid, S.G., Tandel, S.K., Suman, Saket, Srivastava, P.C., Kumar, Anil, Chowdhury, P., Kondev, F.G., Janssens, R.V.F., Carpenter, M.P., Lauritsen, T., Seweryniak, D., and Zhu, S.

Abstract

Metastable states with T$_{1/2}$ = 8(2) ms in $^{205}$Bi and T$_{1/2}$ = 0.22(2) ms in $^{204}$Pb, with ≈ 8 MeV excitation energy and angular momentum ≥ 22 ħ, have been established. These represent, by up to two orders of magnitude, the longest-lived nuclear states above an excitation energy of 7 MeV, ever identified in the nuclear chart. Additionally, the half-life of the 10.17 MeV state in $^{206}$Bi has been determined to be 0.027(2) ms, the next highest value in this highly excited regime. These observations indicate the emergence of an island of extreme nuclear isomerism arising from core-excited configurations at high excitation in the vicinity of the doubly closed-shell nucleus $^{208}$Pb. These results are expected to provide discriminating tests of the effective interactions used in current large-scale shell-model calculations.

Published
2022

35. Isomers in Tl 203 and core excitations built on a five-nucleon-hole structure

Author

Bothe, V., Wahid, S.G., Seweryniak, D., Zhu, S., Carpenter, M.P., Kondev, F.G., Chowdhury, P., Janssens, R.V.F., Srivastava, P.C., Tandel, S.K., Bhoy, B., and Lauritsen, T.

Abstract

Isomers with three- and five-nucleon-hole configurations have been established in Tl203. These include newly identified levels with a three-nucleon-hole structure: Iπ = (15/2-) with T1/2 = 7.9(5) ns and Iπ = (35/2-) with T1/2 = 4.0(5) ns. In addition, five-nucleon-hole states have also been established: Iπ = (39/2-) with T1/2 = 1.9(2) ns and Iπ = (49/2+) with T1/2 = 3.4(4) ns. The previously determined long-lived decay, T1/2 = 6.6(3) μs from this work, is associated with isomerism of the Iπ = (29/2+) state. Levels above this long-lived isomer have been identified through a delayed-prompt γ-γ coincidence measurement. Five-nucleon-hole states with excitation energies Ex≈ 7 MeV have been established as well as possible octupole excitations of the Pb208 core built on these levels. The level scheme of Tl203 is extended up to Ex≈ 11 MeV with the inclusion of 25 new transitions. Empirical and shell-model calculations have been performed to aid in the description of the observed states which are found to be of intrinsic character.

Published
2022
Full Text
View/download PDF

36. Three-phonon multiplets in 116Sn

Author

Ray, Prithwijita, primary, Pai, H., additional, Ali, Sajad, additional, Mukherjee, A., additional, Rajbanshi, S., additional, Chakraborty, S., additional, Bhattacharya, Soumik, additional, Banik, R., additional, Nandi, S., additional, Bhattacharyya, S., additional, Mukherjee, G., additional, Bhattacharya, C., additional, Gangopadhyay, G., additional, Samanta, S., additional, Das, S., additional, Chatterjee, S., additional, Raut, R., additional, Ghugre, S.S., additional, Srivastava, P.C., additional, Jehangir, S., additional, Bhoy, Bharti, additional, Rather, N., additional, Bhat, G.H., additional, Sheikh, J.A., additional, and Goswami, A., additional

Published
2021
Full Text
View/download PDF

42. Deformed shell model results for two-neutrino double-beta decay of [sup.82]Se

Author

Sahu, R., Srivastava, P.C., and Kota, V.K.B.

Subjects
Selenium -- Chemical properties -- Atomic properties, Neutrinos -- Chemical properties -- Composition, Physics
Abstract

The half-life for two-neutrino double-beta decay has been calculated for 82Se, within the framework of the deformed shell model (DSM) based on Hartree-Fock states employing a modified Kuo interaction in ²p3/2, ¹f5/2, 2p1/2, and ¹g9/2 space with single particle energies (relative to a [sup.56]Ni core) for the four orbitals taken as 0.0, 0.78, 1.08, and 4.25 MeV, respectively. A reasonable description is obtained for the spectroscopic properties of yrast levels in 82Se, and similarly in the past [sup.82]Kr was studied successfully using DSM. The half-life calculated using DSM is ~3.56 X [10.sup.20] a compared to the experimental value (0.92 ± 0.07) X [10.sup.20] a. We have also recalculated the half-life by including the ¹f7/2 orbit in the preceding model space using the fpg interaction introduced by Sorlin et al. (Phys. Rev. Lett. 88, 092501 (2002)). The calculated halflife is 2.05 X [10.sup.19] a (0.58 X [10.sup.20] a if we include the quenching factor of 0.77). PACS Nos: 23.40.Hc, 21.10.Tg, 21.60.Jz, 27.50.+e Nous calculons la demi-vie de la double desintegration beta a deux neutrinos du [sup.82]Sn, dans le cadre du modele en couches deformees (DSM) base sur des etats de Hartree-Fock employant une interaction de Kuo modifiee dans l'espace d'etats (²p3/2, ¹f5/2, ²p1/2, ¹g9/2), avec des energies a une particules (relatives au coeur de [sup.56]Ni) pour les quatre orbites prises comme etant 0,0, 0,78, 1,08 et 4,25 MeV respectivement. Nous obtenons ainsi une description raisonnable des proprietes spectroscopiques pour les niveaux d'yrast dans le [sup.82]Se, comme dans le passe le [sup.82]Kr, a ete etudie avec succes en utilisant le DSM. La demi-vie calculee en utilisant le DSM est ~3,56 X [10.sup.20] a, comparee a la valeur experimentale de (0,92 ± 0,07) X 1020 a. Nous avons aussi recalcule la demi-vie en introduisant l'orbite ¹f7/2 dans l'espace modele ci-dessus avec l'interaction fpg de Sorlin et al. (Phys. Rev. Lett. 88, 092501 (2002)). La demi-vie calculee est alors de 2,05 X [10.sup.20] a (0,58 X [10.sup.20] asi nous incluons le facteur de reduction de 0,77). [Traduit par la Redaction], 1. Introduction Double-β decay (DBD) is an extremely rare weak-interaction process in which two identical nucleons inside the nucleus undergo decay with or without emission of neutrinos. Theoretically, the two-neutrino [...]

Published
2011
Full Text
View/download PDF

46. Metastable states from multinucleon excitations in Tl 202 and Pb 203

Author

Suman, S., Janssens, R.V.F., Lister, C.J., Zhu, S., Sharma, A., Singh, R.P., Deo, A.Y., Bhoy, B., Bhattacharjee, S.S., Seweryniak, D., Muralithar, S., Khoo, T.L., Pragati, Carpenter, M.P., Lauritsen, T., Srivastava, P.C., Patel, A., Rai, S., Kondev, F.G., Roy, P., Wahid, S.G., Tandel, S.K., Hemalatha, M., and Chowdhury, P.

Abstract

The excited level structures of Tl202 and Pb203, above the 7+ and 29/2- isomers, respectively, have been studied. An isomer with Iπ=20+ and T1/2=215(10)μs has been established in Tl202, and the level scheme extended from I=10 to 20ℏ with the placement of fifteen new transitions. In Pb203, the Iπ=37/2+ state is established to be metastable, with T1/2=2.5(3)ns. Levels in both nuclei arise from intrinsic excitations, with likely particle-hole character for the higher-lying states in Pb203. The 20+ isomer in Tl202 is most likely associated with a πh11/2-1 - ν(i13/2-2,f5/2-1) configuration, while the 37/2+ state in Pb203 results from the excitation of five neutrons. Calculations, using both an empirical approach and the oxbash code, have been performed to aid in the description of the excited level structure.

Published
2020
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results