Münster 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HK: Fachverband Physik der Hadronen und Kerne
HK 23: Nuclear Astrophysics II
HK 23.3: Vortrag
Dienstag, 28. März 2017, 14:45–15:00, F 33
Expansion of the equation of state of neutron-rich nuclear matter from χEFT beyond quadratic order — •Susanne Strohmeier and Norbert Kaiser — Technische Universität München
Based on chiral effective field theory, the equation of state of neutron-rich nuclear matter is investigated systematically. The contributing diagrams up to three-loop order include one- and two-pion exchange together with three-body terms arising from virtual Δ(1232)-isobar excitations. The expansion of the energy per particle in the proton fraction δ for the nuclear many-body system with neutron density ρn= kf3 (1−δ)/3 π2 and proton density ρp= kf3 δ/3 π2 is performed analytically up to quadratic order: Ē(kf,δ) = Ēn(kf) + δ B1(kf) +δ5/3 B5/3 (kf) + δ 2 B2 (kf) + … . Yet higher orders in the δ-expansion are necessary for a reasonable description of the equation of state for proton fractions above 20%. The evaluation of a S-wave contact interaction to second order establishes a non-analytical δ7/3lnδ-term. The higher order coefficients of the expansion are determined by a least-squares fit. With terms up to order δ8/3 a good description is obtained from pure neutron matter (δ=0) up to symmetric nuclear matter (δ=0.5).
Work supported in part by DFG and NSFC (CRC110).