Nuclear electric polarizability of 6He

We present an estimate of the nuclear electric polarizability α_E of the 6He halo nucleus based on six-body microscopic calculations. Wave functions are obtained from semirealistic two-body interactions using the hyperspherical harmonics expansion method. The polarizability is calculated as a sum rule of the dipole response function using the Lanczos algorithm and also by integrating the photoabsorption cross section calculated via the Lorentz integral transform method. We obtain α_E=1.00(14) fm3, which is much smaller than the published value αEexp=1.99(40) fm3 [Pachucki and Moro, Phys. Rev. APLRAAN1050-294710. 1103/PhysRevA.75.032521 75, 032521 (2007)] extracted from experimental data. This points toward a potential disagreement between microscopic theories and experimental observations.