Eur. Phys. J. A (2005) 23: 473-480
https://doi.org/10.1140/epja/i2004-10109-6

Fusion-evaporation cross-sections for ⁴⁸Ca + ¹⁵⁴Sm near the Coulomb barrier

Evidence for fusion enhancement and hindrance

¹ INFN - Laboratori Nazionali di Legnaro, viale dell’Università 2, I-35020, Legnaro (Padova), Italy
² INFN - Sezione di Napoli and Dipartimento di Fisica, Università di Napoli, Italy
³ Dipartimento di Fisica, Università di Padova and INFN, Sezione di Padova, Padova, Italy
⁴ Flerov Laboratory of Nuclear Reactions, JINR, 141980, Dubna, Moscow region, Russia
⁵ IReS, UMR 7500, IN2P3-CNRS/Université Louis Pasteur, B.P. 28, F-67037, Strasbourg Cedex 2, France

^* e-mail: alberto.stefanini@lnl.infn.it

Received: 15 October 2004
Accepted: 24 November 2004
Published online: 12 January 2005

Abstract

Measurements of fusion-evaporation cross-sections for the system ⁴⁸Ca + ¹⁵⁴Sm have been performed in the sub- and near-barrier energy range. Barrier-passing cross-sections have been obtained by adding recently measured capture-fission cross-sections at the same energies, and the barrier distribution for capture has been extracted. The data have been analyzed within a coupled-channel model, and a large subbarrier cross-section enhancement is observed, due to the ground-state prolate deformation of ¹⁵⁴Sm. The ⁴⁸Ca + ¹⁵⁴Sm capture cross-sections are compared to existing data on ¹⁶O + ¹⁸⁶W fusion, leading to the same CN, where a few higher-energy points have also been measured. The evaporation residue cross-sections for the two systems above the barrier indicate that complete fusion is inhibited for ⁴⁸Ca + ¹⁵⁴Sm by ≈ 40% in that energy region, with respect to ¹⁶O + ¹⁸⁶W.