Generalized oscillator strength for the argon 3p(6)-3p(5)4s transition: Correlation and exchange effects on the characteristic minimum

We have investigated the generalized oscillator strength (GOS) for a transi tion of the type np->(n + 1)s, where n is the principal quantum number of t he outermost filled shell of the atomic ground state, using the random-phas e approximation with exchange. We find that the influence of correlation an d exchange effects on the position of the characteristic minimum in the GOS of Ar(n =3) is insignificant. Also, our first Born approximation predicts the position of the minimum accurately provided that accurate target wave f unctions are employed. Our results agree excellently with measurements and are expected to be applicable equally to the corresponding subshells of Ne( n = 2), Kr(n = 4), and Xe(n = 5).