Eur. Phys. J. A (2006) 29: 151-159
https://doi.org/10.1140/epja/i2006-10084-x

Nuclear Structure and Reactions

Spin-parity measurements in the neutron-rich N ∼ 20 ³⁴P and ³⁶S nuclei

¹ UGC-DAE Consortium for Scientific Research, Kolkata Centre, Sector III/LB-8, Bidhan Nagar, 700 098, Kolkata, India
² Department of Physics, The University of Burdwan, 713 104, Burdwan, India
³ Department of Physics, University of Notre Dame, 46556, Notre Dame, IN, USA
⁴ Variable Energy Cyclotron Centre, Sector-I/AF, Bidhan Nagar, 700 064, Kolkata, India
⁵ Department of Physics, Govt. College, 324 009, Kota, India
⁶ Department of Physics, Banaras Hindu University, 221 005, Varanasi, India
⁷ Saha Institute of Nuclear Physics, 700 064, Kolkata, India
⁸ Department of Physics and Astrophysics, University of Delhi, 110 007, New Delhi, India
⁹ Nuclear Science Centre, Aruna Asaf Ali Marg, 110 067, New Delhi, India

Received: 5 January 2006
Accepted: 10 August 2006
Published online: 6 September 2006

Abstract

Yrast and near-yrast energy levels in the neutron-rich N ∼ 20 nuclei ³⁴P, ³⁶S were populated using transfer/deep-inelastic processes following the ³⁴S + ¹¹⁵In reaction at an incident energy of 140MeV. The use of a multi-clover array has facilitated polarization measurements of the observed γ-rays and necessitated some changes in the previously known level scheme. The observation of the negative-parity levels in these nuclei on the periphery of the “island of inversion” is indicative of the influence of the intruder orbitals on the level structure at low spins. Shell-model calculations indicate that the inclusion of the orbitals from the upper pf shell is important even for the low-lying positive-parity states.