Experimental determination of Gamow-Teller quenching value, Landau-Migdal parameter glNΔ and pion condensation

The Gamow-Teller quenching value Q is determined experimentally; Q = 0.89 +/- 0.04(sta + MDA) +/- 0.04(IVSM) apart from the systematic uncertainty of Delta(σ) over cap GT less than or equal to 15%. To accomplish this aim both Zr-90(p, n) and Zr-90(n, p) reactions have been measured at 300 MeV. Both data were analyzed simultaneously by means of the multipole decomposition analysis (MDA). This allows us to derive reliable B(GT(+/-)) strengths. The Landau-Migdal (LM) parameters representing a short-range correlation in isospin-spin channel are deduced from the Q value as g'(NN) = 0.60 +/- 0.02 and g'(NDelta) = 0.24 +/- 0.10. The critical density N of the pion condensation can be estimated by using these LM parameters to be p(c) similar to 2rho(0) which can be easily realized in neutron stars. Recent observation of the surface temperature of the neutron star 3C58 supports the picnic cooling mechanism and consequent manifestation of the pion condensation in neutron stars.