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Relativistic study of medium polarization effects on superfluidity in neutron matter. nuclear. Masayuki Matsuzaki. (Fukuoka University of Education). Medium polarization effect on superfluidity. Neutron matter. reduce pairing gap significantly. reduction is weak. Symmetric matter.
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Relativistic study of medium polarization effects on superfluidity in neutron matter nuclear Masayuki Matsuzaki (Fukuoka University of Education) M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
Medium polarization effect on superfluidity Neutron matter reduce pairing gap significantly reduction is weak M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
Symmetric matter … preliminary enhance pairing gap Finite nuclei enhance pairing gap M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
Relativistic approach (σ-ω model) M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
Thermodynamics at T=0 Liquid-gas instability ! M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
Quantum mechanics 0 calculate meson propagator (q =0) M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
Nucleon propagator 0 k : pha decomposition --- M.Nakano et al., PRC56, 3287 (1997) xxx xxx xxx : FD decompositon --- standard ( ) ,
(Longitudinal) dielectric function pha FD instability ! instability ! M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
ill-defined at instability ! Pairing interaction at 1-loop level
(Cross section of dielectric function) free from instability infra-red cutoff is necessary 0.65 is chosen
(instability) (corrected using a form factor at tree (OBE) level)
Form factor at every vertex to modulate high mom. interaction so as to reproduce the result of Bonn-B potential present M.M. and T.Tanigawa, NPA683, 406 (2001) M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
FD attraction repulsion pha σ,longitudinal-ω:attraction, σ-ωmix: repulsion
Neutron matter instability M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
Summary • Liquid-gas instability occurs at medium density • Medium polarization enhances gap at low and medium density • At high density, FD enhances gap whereas pha reduces gap • Characteristic cancellation among σ,ω, and σ-ωmix • Result for neutron matter is similar M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
Acknowledgement • Prof. P. Ring (Munich) for suggesting the problem • Prof. H.Kouno (Saga) for useful discussions M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
FD attraction pha M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006
(Preliminary cal.) pha FD OBE M.M. and P.Ring, nucl-th/9712060 M. Matsuzaki, RIKEN "Mean-field theories and beyond", Mar. 21, 2006