ar X iv : n uc l - th / 0 41 10 32 v 1 9 N ov 2 00 4 Recent Developments in the Lorentz Integral Transform ( LIT ) Method

Recent results on electromagnetic (e.m.) reactions into the continuum of systems with A from 3 to 7 are presented. They have been obtained using the LIT method [1]. The method is shortly reviewed, emphasizing how all the results, though obtained with the sole ingredient of the N-N potential, contain the full complicated dynamics of the A-body system, both in the initial and in the final states. The LIT method is suited for ab initio studies of few (many) body dynamics in the framework of non relativistic quantum mechanics. The inputs are the nuclear potential and the excitation operator relevant to the reaction. Even if the reaction brings the system to a continuum state one does not need to calculate continuum wave functions. What the method allows to calculate are matrix elements (or combinations of them) to continuum states, which is what one needs in order to evaluate cross sections. Essential to the method are solutions of the Schrödinger equation for the ground state and of a Schrödinger-like equation with a source. In both cases the solutions have bound-state asyntotic conditions. So in order to apply the LIT method one only needs a "good" technique for bound state calculations. The LIT method applies both to inclusive reactions and to exclusive ones. In a traditional approach the former case is considered more complicated, because of the necessity to know solutions for all the disintegration channels. However, it turns out that the application of the LIT method is more straightforward in this case than in an exclusive reaction. The LIT method has been benchmarked in 2-and 3-body systems where continuum states can be calculated directly [1, 3, 4, 5] The procedure of the LIT method, though similar in spirit, is different for inclusive and exclusive reactions. In the following I will list the main steps one has to take in the two cases.