Pionic modes studied by quasielastic ((p)over-right-arrow,(n)over-right-arrow) reactions

It has long been expected that the picnic modes show some collective phenomena such as the pion condensation in the high density nuclear matter and its precursor phenomena in the ordinary nuclei. Here we show an evidence of the precursor observed in the isovector spin longitudinal cross sections IDq of the quasielastic C-12, Ca-40 ((p) over right arrow,(n) over right arrow) reactions at T-p = 346 and 494MeV with the momentum transfer q =1.7fm(-1). Another aim of this report is to evaluate the Landau-Migdal parameters 9'(N,N), 9'(N Delta) and 9'(Delta Delta) at the large momentum region from the above reactions. We obtained 9'(NN) approximate to 0.6 - 0.7, g(N Delta) approximate to 0.3 - 0.4. The results are consistent with those at the small momentum region, which are obtained from the Gamov-Teller strength distribution.