NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA A-NUCLEI PARTICLES AND FIELDS, vol.105, no.5, pp.703-709, 1992 (SCI-Expanded)
The isotopic-spin impurity introduced to the ground state of an alpha-particle by the Coulomb plus specifically charge-dependent nuclear forces is investigated. The upper limit of the impurity is calculated by shell model wave functions. The sum of the squared amplitudes of T=1, L not-equal 0 states is found to be in the order of 10(-4), which is one order of magnitude greater than earlier predictions.