6533b859fe1ef96bd12b7f69

RESEARCH PRODUCT

Halo excitations in fragmentation of He at 240 MeV/u on carbon and lead targets

R. HolzmannMikael MeisterMikael MeisterTh. W. ElzeThomas NilssonKarin MarkenrothM. H. SmedbergW. DostalThomas AumannG. KrausJ. HoleczekBrian PetersenDmitry AleksandrovL. AxelssonA. LeistenschneiderA. GrünschloßL. V. ChulkovMargareta HellströmHans GeisselK. RiisagerJ. V. KratzC. ScheidenbergerY. LeifelsH. EmlingAchim RichterGöran Hugo NymanF. NickelM. PfütznerBjörn JonsonV. Z. GoldbergR. KulessaG. MünzenbergV. PriboraA. SurowiecT. LethHaik SimonHaik SimonThomas BaumannOlof TengbladB. EberleinJoachim StrothMaría José García BorgeW. SchwabJ. CubG. SchriederMikhail V. ZhukovMikhail V. ZhukovI. Mukha

subject

PhysicsNuclear and High Energy PhysicsFragmentation (mass spectrometry)QuadrupoleCoulombHalo nucleusNeutronAtomic physicsInelastic scatteringResonance (particle physics)Excitation

description

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.

yearjournalcountryeditionlanguage
2000-04-01Nuclear Physics A
https://doi.org/10.1016/s0375-9474(99)00825-8