The main result of the study is that, in this example, the quantum mechanical predictions violate the Leggett-Garg inequality even for particles with large mass. This implies that either the particle does not obey realism or that the measurements are invasive. But as the physicists ruled out the latter by proposing to use a measurement procedure called the negative result measurement, which is specifically designed to be noninvasive, the results indicate that the particle does not obey realism, a sign of nonclassical behavior.

"In this context, our work opens up a novel direction for testing macrorealism by showing that the quantum mechanical violation of macrorealism is testable for a system like a harmonic oscillator, which has a well-defined classical description and is initially in a state which is the most classical-like of all quantum states, the harmonic oscillator coherent state."