One of the main problems in trying to understand quantum physics is the nature of the referent of quantum theory. This point is addressed in the official French curriculum in upper secondary school. Starting in 2012, after about 20 years of absence, quantum physics has returned to the national program. On the basis of the historical construction of quantum physics, we identify two epistemological positions with respect to this problem: The first one (close to the so-called Copenhagen school) is termed the conservative position and the second one (associated with the work of Bunge and Lévy-Leblond) the innovative position. We then analyze French textbooks used by teachers, in order to reveal the implicit positions adopted. We conclude with the idea that highlighting these epistemological choices can help teachers reflect upon the historical and epistemological roots of quantum physics. Such an analysis can contribute to developing and implementing appropriate teaching sequences for quantum physics. We explore the application of these epistemological positions to Young's paradigmatic experiment using the double slits.

Isospin effects on multifragmentation properties were studied thanks to nuclear collisions between different isotopes of xenon beams and tin targets. It is shown that, in central collisions leading to multifragmentation, the mean number of fragments and their mean kinetic energy increase with the neutron-richness of the total system. Comparisons with a stochastic transport model allow to attribute the multiplicity increase to the multifragmentation stage, before secondary decay. The total charge bound in fragments is proposed as an alternate variable to quantify preequilibrium emission and to investigate symmetry energy effects.