Experimental determination of Gamow-Teller quenching value, Landau-Migdal parameterg′NΔ and pion condensation Original Research Article

The Gamow-Teller quenching valueQ is determined experimentally;Q = 0.89 ± 0.04(sta + MDA) ± 0.04(IVSM) apart from the systematic uncertainty ofΔgˆsGT ≤ 15%. To accomplish this aim both9OZr(p, n) and90Zr(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 reliableB(GT±) strengths. The Landau-Migdal (LM) parameters representing a short-range correlation in isospin-spin channel are deduced from theQ value asg′NN = 0.60 ± 0.02 andg′NΔ = 0.24 ± 0.10. The critical density of the pion condensation can be estimated by using these LM parameters to beϱc ∼ 2ϱ0 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.