title: Normal state of a polarized fermi gas at unitarity.
abstract: We study the Fermi gas at unitarity and at T=0 by assuming that, at high polarizations, it is a normal Fermi liquid composed of weakly interacting quasiparticles associated with the minority spin atoms. With a quantum Monte Carlo approach we calculate their effective mass and binding energy, as well as the full equation of state of the normal phase as a function of the concentration x=n downward arrow/n upward arrow of minority atoms. We predict a first order phase transition from normal to superfluid at x(c)=0.44 corresponding, in the presence of harmonic trapping, to a critical polarization P(c)=(N upward arrow - N downward arrow/(N upward arrow + N downward arrow)=77%. We calculate the radii and the density profiles in the trap and predict that the frequency of the spin dipole mode will be increased by a factor of 1.23 due to interactions.
authors.affiliation: Dipartimento di Fisica, Università di Trento and CNR-INFM BEC Center, I-38050 Povo, Trento, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Lobo
authors.forename: A
authors.initials: A
authors.lastname: Recati
authors.forename: S
authors.initials: S
authors.lastname: Giorgini
authors.forename: S
authors.initials: S
authors.lastname: Stringari