Delta baryons are the first excitations of the nucleons that can bemeasured in nuclear matter and experimental data on some resonances point to a general broadening of these states with a small effect to their masses. More recent data seems to indicate a stronger effect to the mass of states at higher densities, what is more in line with early theoretical studies, which predict dropping hadron masses at finite density.The QCD sum rules are naturally suited to study hadrons in nuclear matter as the effects of themedium are encoded in effects on the condensates. Several works have studied the value of these condensates in medium and highlighted the importance of four-quark condensates, which, in the vacuum, can be described in terms of two-quark condensates but not so in the nuclear medium.During the program we will collaborate to improve the existing results on the QCDSR for the delta in nuclear matter. The aim is to do a deeper study of the interpolating currents and compare with the recent results obtained for the neutron and hyperons.
News published in Agência FAPESP Newsletter about the scholarship: