Isovector soft dipole mode in 6Be
Abstract
By using the 1H(6Li,6Be)n charge-exchange reaction, continuum states in 6Be were populated up to E_t=16 MeV, E_t being the 6Be energy above its three-body decay threshold. In kinematically complete measurements performed by detecting alpha+p+p coincidences, an E_t spectrum of high statistics was obtained, containing approximately ~5x10^6 events. The spectrum provides detailed correlation information about the well-known 0^+ ground state of 6Be at E_t=1.37 MeV and its 2^+ state at E_t=3.05 MeV. Moreover, a broad structure extending from 4 to 16 MeV was observed. It contains negative parity states populated by Delta L=1 angular momentum transfer without other significant contributions. This structure can be interpreted as a novel phenomenon, i.e. the isovector soft dipole mode associated with the 6Li ground state. The population of this mode in the charge-exchange reaction is a dominant phenomenon for this reaction, being responsible for about 60% of the cross section obtained in the measured energy range.
Cite
@article{arxiv.1106.2179,
title = {Isovector soft dipole mode in 6Be},
author = {A. S. Fomichev and V. Chudoba and I. A. Egorova and S. N. Ershov and M. S. Golovkov and A. V. Gorshkov and V. A. Gorshkov and L. V. Grigorenko and G. Kamiński and S. A. Krupko and I. G. Mukha and Yu. L. Parfenova and S. I. Sidorchuk and R. S. Slepnev and L. Standyło and S. V. Stepantsov and G. M. Ter-Akopian and R. Wolski and M. V. Zhukov},
journal= {arXiv preprint arXiv:1106.2179},
year = {2015}
}
Comments
8 pages, 7 figures