Reappraisal of the Rho Meson in Nuclear Matter by the Inverse QCD Sum Rules Method

Abstract

We present a comprehensive reappraisal of the in-medium properties of the rho meson using the inverse QCD sum rules (QCDSR) formalism, offering a novel, model-independent approach to studying hadronic modifications in nuclear matter. Unlike conventional QCDSR, which rely on a predefined pole & thorn; continuum structure, the inverse method reconstructs the spectral function directly from the operator product expansion (OPE), eliminating assumptions about the spectral ansatz. To the best of our knowledge, this is the first application of the inverse QCDSR method to the rho meson in nuclear matter. Our analysis reveals a significant reduction in the rho meson mass, consistent with previous theoretical predictions, and highlights the crucial role of medium-induced modifications, including condensate suppression and factorization-breaking effects. Furthermore, we assess the sensitivity of our results to the factorization assumption and higher-dimensional condensates, demonstrating the necessity of refining nonperturbative contributions for an accurate description of in-medium hadron properties. Our findings establish the inverse QCDSR method as a robust alternative to conventional spectral analysis techniques, providing a systematically controlled framework for exploring strongly interacting matter under extreme conditions. These results offer important theoretical benchmarks for lattice QCD simulations and heavy-ion collision experiments, shedding light on the restoration of chiral symmetry and the evolution of hadronic matter in dense environments.