Extreme Qcd 2012 (Xqcd)
Systems of non-zero isospin chemical potential are studied from a canonical approach by computing correlation functions with the quantum numbers of N pi(+)'s (C-N pi). In order to reduce the number of contractions required in calculating C-N pi for a large N in the Wick's theorem, we constructed a few new algorithms. With these new algorithms, systems with isospin charge up to 72 are investigated on three anisotropic gauge ensembles with a pion mass of 390 MeV, and with lattice spatial extents L similar to 2.0, 2.5, 3.0 fm. The largest isospin density of rho(I) approximate to 9 fm(-3) is achieved in the smallest volume, and the QCD phase diagram is investigated at a fixed low temperature at varying isospin chemical potentials, m(pi) < mu(I) < 4.5 m(pi). By investigating the behaviour of the extracted energy density of the system at different isospin chemical potentials, we numerically identified the conjectured transition to a Bose-Einstein condensation state at mu(I) >= m(pi).
Shi, Z. (2013). Lattice QCD at non-zero isospin chemical potential. In Journal of Physics: Conference Series (Vol. 432, No. 1, p. 012026). IOP Publishing.