New results on the halo structure of B-8

Authors
Smedberg, MH Baumann, T Aumann, T Axelsson, L Bergmann, U Borge, MJG Cortina-Gil, D Fraile, LM Geissel, H Grigorenko, L Hellstrom, M Ivanov, M Iwasa, N Janik, R Jonson, B Lenske, H Markenroth, K Munzenberg, G Nilsson, T Richter, A Riisager, K Scheidenberger, C Schrieder, G Schwab, W Simon, H Sitar, B Strmen, P Summerer, K Winkler, M Zhukov, MV
Citation
Mh. Smedberg et al., New results on the halo structure of B-8, PHYS LETT B, 452(1-2), 1999, pp. 1-7
Citations number
22
Categorie Soggetti
Physics
Journal title
PHYSICS LETTERS B
ISSN journal
03702693 → ACNP
Volume
452
Issue
1-2
Year of publication
1999
Pages
1 - 7
Database
ISI
SICI code
0370-2693(19990415)452:1-2<1:NROTHS>2.0.ZU;2-E
Abstract
The longitudinal momentum distribution of Be-7 fragments after fragmentatio n of B-8 and the one-proton removal cross section (sigma(-1p)) in a carbon target were measured at 1440 MeV/u with the fragment separator FRS used as an energy-loss spectrometer. The results show a narrow momentum distributio n with a FWHM value of 91 +/- 5 MeV/c and a large cross-section, sigma(-1p) = 98 +/- 6 mb. Both these results support the interpretation of a spatiall y extended proton orbit forming a halo in the B-8 ground state. The momentu m distribution and the: one-proton removal cross section are shown to be re produced with a three-body wave function for B-8 where the target is treate d as a black disc in the breakup process. (C) 1999 Published by Elsevier Sc ience B.V. All rights reserved.