1996/03/22 by Michael C. Birse, Boris Krippa · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Nuclear physics research studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1016/0370-2693(96)00636-3
published as Phys.Lett. B381 (1996) 397-401 · 11 pages (RevTeX)
arxiv created 1996/03/22 · openalex publication_date 1996/07/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The quark condensate in nuclear matter contains a term of order ρmπ, arising from the contribution of low-momentum virtual pions to the πN sigma commutator. Standard treatments of QCD sum rules for a nucleon in matter generate a similar term in the nucleon effective mass, although this is inconsistent with chiral perturbation theory. We show how an improved treatment of pionic contributions on the phenomenological side of the sum rules can cancel out this unwanted piece. Our results also show that factorisation ansatz for the four-quark condensate cannot be valid in matter.