On the accuracy of hyperspherical harmonics approaches to photonuclear reactions

Using the Lorentz integral transform (LIT) method we compare the results for the triton total-photodisintegration cross section obtained using the correlated hyperspherical harmonics (CHH) and the effective interaction hyperspherical harmonics (EIHH) techniques. We show that these two approaches, while rather different both conceptually and computationally, lead to results which coincide within high accuracy. The calculations which include two- and three-body forces are of the same high quality in both cases. We also discuss the comparison of the two approaches in terms of computational efficiency. These results are of major importance in view of applications to the much debated case of the four-nucleon photoabsorption. (author)