Halo excitations in fragmentation of He-6 at 240 MeV/u on carbon and lead targets
Artikel i vetenskaplig tidskrift, 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

Författare

D. Aleksandrov

T. Aumann

Leif Axelsson

Chalmers, Institutionen för experimentell fysik, Subatomär fysik

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, Institutionen för experimentell fysik, Subatomär fysik

J. V. Kratz

G. Kraus

R. Kulessa

Y. Leifels

A. Leistenschneider

T. Leth

Karin Markenroth

Chalmers, Institutionen för experimentell fysik, Subatomär fysik

Mikael Meister

Chalmers, Institutionen för experimentell fysik, Subatomär fysik

I. Mukha

G. Munzenberg

F. Nickel

Göran Hugo Nyman

Chalmers, Institutionen för experimentell fysik, Subatomär fysik

B. Petersen

M. Pfutzner

V. Pribora

A. Richter

K. Riisager

C. Scheidenberger

G. Schrieder

W. Schwab

H. Simon

Martin Smedberg

Chalmers, Institutionen för experimentell fysik, Subatomär fysik

J. Stroth

A. Surowiec

O. Tengblad

Mikhail Zhukov

Chalmers, Institutionen för experimentell fysik, Subatomär fysik

Nuclear Physics A

0375-9474 (ISSN)

Vol. 669 51-64

Ämneskategorier

Subatomär fysik