The present disclosure provides a process. In an embodiment, the process includes providing a neat ethylene/ propy-lene/non-conjugated polyene terpolymer (n-terpolymer) having a Mooney viscosity (ML (1+4) at 125C) less than 100 Mooney units (MU). The process includes exposing the n-terpolymer to electron beam radiation at a dosage from 0.2 megaRad (MRad) to 1.3 MRad. The process includes forming a branched ethylene/propylene/non-conjugated polyene terpolymer (b-terpolymer) having a Mooney viscosity ML (1+4) at 125C from 25 MU to 135 MU.