Speaker
Description
We investigate the chemical-potential dependence of hadron masses in two-color QCD (QC$_2$D) using first-principles lattice simulations. QC$_2$D provides a useful theoretical laboratory for studying cold dense QCD matter, since it is free from the sign problem while sharing several important nonperturbative features with three-color QCD. In this work, we compute two-point correlation functions for all allowed hadronic operators, newly including contributions from disconnected diagrams, and extract the corresponding effective masses at finite quark chemical potential.
In the meson sector, we find that the mass hierarchy in the hadronic phase is qualitatively similar to that in three-color QCD, while it is substantially modified after the onset of the superfluid phase. In the diquark sector, the Nambu--Goldstone mode associated with the spontaneous breaking of U(1)_B is confirmed to be nearly massless, and the ordering of the diquark spectrum remains relatively stable across the transition. We also compare correlators of chiral partners and find indications of chiral symmetry restoration at high density.
Our results provide a systematic view of how hadronic excitations evolve from the normal vacuum to dense superfluid matter in QC$_2$D, and offer useful benchmarks for effective theories of dense QCD-like matter.
This talk is based on arXiv:2606.13974.