Reorientation-effect measurement of the <2[subscript 1][superscript +] [parallel to] E[hat] 2 [parallel to] 2[subscript 1][superscript +]> matrix element in [superscript 10]Be

Abstract

The highly-efficient and segmented TIGRESS [gamma]-ray spectrometer at TRIUMF has been used to perform a reorientation-effect Coulomb-excitation study of the 2[subscript1][superscript +] state at 3.368 MeV in [superscript 10]Be. This is the first Coulomb-excitation measurement that enables one to obtain information on diagonal matrix elements for such a high-lying first excited state from [gamma]-ray data. With the availability of accurate lifetime data, a value of −0.110 ± 0.087 eb is determined for the [untranscribable characters] diagonal matrix element, which assuming the rotor model, leads to a negative spectroscopic quadrupole moment of Q[subscript s](2[subscript1][superscript +] ) = −0.083 ± 0.066 eb. This result is in agreement with both no-core shell-model calculations performed in this work with the CD-Bonn 2000 two-nucleon potential and large shell-model spaces, and Green’s function Monte Carlo predictions with two- plus three-nucleon potentials.