Isospin effects in two-particle correlation functions: A probe for the isospin dependence of the nuclear equation of state

Small-angle two-particle correlation functions, involving neutrons and protons, have been measured for E/A=61 MeV Ar+Sn112,124 collisions, i.e. systems similar in size but with different isospin asymmetry. The correlation strength of neutron-proton (np) and proton-proton (pp) pairs is stronger for the more neutron-rich system, indicating a shorter average emission time for this system. Comparisons with isospin-dependent BUU transport model simulations are presented, and their implications for the density dependence of the nuclear symmetry energy are discussed.