A beam of electrons and a beam of neutral carbon-60 (\(\text{C}_{60}\)) fullerene molecules are each prepared such that the particles in both beams have the same kinetic energy \(K\). Each beam is directed through an identical transmission diffraction grating with slit spacing \(d\), and the resulting pattern of detected particles is recorded on a screen located a distance \(L\) behind the grating. Although both beams produce distinct interference fringes on the screen, the fringe spacing \(\Delta y\) for the \(\text{C}_{60}\) beam is significantly smaller than that for the electron beam. Which of the following statements provides the correct physical explanation for this observation?