In-medium Σ0–Λ mixing in QCD sum rules

✍ Scribed by N. Yagisawa; T. Hatsuda; A. Hayashigaki

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 281 KB
• Volume: 699
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(01)01293-3

✦ Synopsis

The 0 -mixing angle in isospin-asymmetric nuclear medium is investigated by using QCD sum rules. From the general consideration of the in-medium baryonic correlations, in-medium baryon mixings are shown to have several Lorentz structures such as the scalar mixing angle θ S and the vector mixing angle θ V . This causes a difference between the particle mixing θ (= θ S + θ V ) and the antiparticle mixing θ (= θ Sθ V ). From the finite-energy sum rules for the 0 -mixing, we find that the in-medium part of the mixing angle has a relation θ S Med ∼ -θ V Med in the isospin-asymmetric medium. This implies that the medium affects mainly the antiparticle mixing. From the Borel sum rules, we obtain |θθ 0 | 0.39|(ρ nρ p )|/ρ 0 with θ 0 , ρ n , ρ p and ρ 0 being the vacuum mixing angle, the neutron density, the proton density and the normal nuclear matter density, respectively.