Electric quadrupole moments and strong interaction effects in pionic atoms of 165Ho, 175Lu, 176Lu, 179Hf and 181Ta

Abstract The effective quadrupole moments Q eff of the nuclei of 165 Ho, 175 Lu, 176 Lu, 179 Hf and 181 Ta were accurately measured by detecting the pionic atom 5g-4f X-rays of the elements. The spectroscopic quadropole moments, Q spec , were obtained by correcting Q eff for nuclear finite size effect, distortion of the pion wave function by the pion-nucleus strong interaction, and contribution to the energy level splittings by the strong interaction. The intrinsic quadrupole moments, Q 0 , were obtained by projecting Q spec into the frame of reference fixed on the nucleus. The shift, e 0 , and broadening, Γ 0 , of the 4f energy level due to the strong interaction between the pion and the nucleons for all the elements were also measured. Theoretical values of e 0 and Γ 0 were calculated and compared to the experimental values. The measured values of Q 0 were compared with existing results in muonic and pionic atoms. The measured values of e 0 and Γ 0 were also compared with existing values.