Halo excitations in fragmentation of He-6 at 240 MeV/u on carbon and lead targets
Journal article, 2000

Dissociation of a 240 MeV/u beam of He-6, incident on carbon and lead targets, has been studied in kinematically complete experiments to investigate low-lying excitation modes in the halo nucleus He-6. It is shown that alignment effects characterize the inelastic scattering and allow an unambiguous assignment of the spin of a narrow resonance observed in the excitation energy spectrum. The differential cross sections for the He-6 inelastic scattering on carbon and lead targets were deduced from the measured moments of the two neutrons and the a-particle. An analysis of these distributions shows that quadrupole and, possibly, monopole excitations characterize the hadronic interaction, while the dipole mode is dominating in Coulomb dissociation. Neither theoretically predicted new resonance states in He-6 nor nuclear excitation of a dipole mode were found. Direct evidence has been obtained for strong suppression of Coulornb post-acceleration in direct Coulomb breakup in a lead target.

nuclei

spectrum

c-12

be-11

resonances

states

inelastic-scattering

model

li-11

breakup

Author

D. Aleksandrov

T. Aumann

Leif Axelsson

Chalmers, Department of Experimental Physics, Subatomic Physics

T. Baumann

M. J. G. Borge

L. V. Chulkov

J. Cub

W. Dostal

B. Eberlein

T. W. Elze

H. Emling

H. Geissel

V. Z. Goldberg

A. Grunschloss

M. Hellstrom

J. Holeczek

R. Holzmann

Björn Jonson

Chalmers, Department of Experimental Physics, Subatomic Physics

J. V. Kratz

G. Kraus

R. Kulessa

Y. Leifels

A. Leistenschneider

T. Leth

Karin Markenroth

Chalmers, Department of Experimental Physics, Subatomic Physics

Mikael Meister

Chalmers, Department of Experimental Physics, Subatomic Physics

I. Mukha

G. Munzenberg

F. Nickel

Thomas Nilsson

Göran Hugo Nyman

Chalmers, Department of Experimental Physics, Subatomic Physics

B. Petersen

M. Pfutzner

V. Pribora

A. Richter

K. Riisager

C. Scheidenberger

G. Schrieder

W. Schwab

H. Simon

Martin Smedberg

Chalmers, Department of Experimental Physics, Subatomic Physics

J. Stroth

A. Surowiec

O. Tengblad

Mikhail Zhukov

Chalmers, Department of Experimental Physics, Subatomic Physics

Nuclear Physics A

0375-9474 (ISSN)

Vol. 669 1-2 51-64

Subject Categories

Subatomic Physics

More information

Created

10/7/2017