Precision measurement of the electromagnetic dipole strengths in Be11

The electromagnetic dipole strength in Be11 between the bound states has been measured using low-energy projectile Coulomb excitation at bombarding energies of 1.73 and 2.09 MeV/nucleon on a Pt196 target. An electric dipole transition probability B(E1;1/2−→1/2+)=0.102(2) e2fm2 was determined using the semi-classical code Gosia, and a value of 0.098(4) e2fm2 was determined using the Extended Continuum Discretized Coupled Channels method with the quantum mechanical code FRESCO. These extracted B(E1)B(E1) values are consistent with the average value determined by a model-dependent analysis of intermediate energy Coulomb excitation measurements and are approximately 14%14% lower than that determined by a lifetime measurement. The much-improved precisions of 2% and 4% in the measured B(E1)B(E1) values between the bound states deduced using Gosia and the Extended Continuum Discretized Coupled Channels method, respectively, compared to the previous accuracy of ∼10%∼10% will help in our understanding of and better improve the realistic inter-nucleon interactions.