A new theoretical framework combining lattice Quantum Chromodynamics (lattice QCD) with potential Non-Relativistic QCD (pNRQCD) has enabled the calculation of inclusive hadronic decay widths for P-wave quarkonia. This advance addresses a long-standing challenge in first-principles QCD, where precise prediction of these decays has been particularly complex. The methodology focuses on heavy quarkonia, which are bound states of a heavy quark and antiquark, such as charmonium and bottomonium.

At leading order in the velocity expansion, all non-perturbative effects, apart from the square of the derivative of the wavefunction at the origin, are encoded in a single universal moment of the two-point chromoelectric correlator. This correlator has been determined for the first time from a quenched lattice QCD calculation, matched to the $\overline{\mathrm{MS}}$ scheme via the gradient flow. This approach allows for a rigorous description of the strong interactions governing these decays.

By combining this result with perturbative short-distance coefficients and the square of the derivative of the wavefunction at the origin, the framework reproduces the observed widths for the $\chi_{cJ}(1P)$ states. Furthermore, it provides predictions for the widths of the $\chi_{bJ}(nP)$ states, which have not yet been experimentally measured. This new method not only validates predictions against existing data but also opens the door to exploring inclusive decays and production of ordinary and exotic hadrons, extending its applicability to a broader range of phenomena in particle physics.