Stationary scattering theory on mainifolds, I

We study spectral theory for the Schrodinger operator on manifolds possessing an escape function. A particular class of examples are manifolds with Euclidean and/or hyperbolic ends.Comment: pp 3

Spin-Polarization Response Functions in High-Energy (e,e'p) Reactions

Spin-polarization response functions are examined for high-energy $(\vec{e},e'\vec{p})$ reaction by computing the full 18 response functions for the proton kinetic energy $T_{p'}=$ 0.515 GeV and 3.179 GeV with an 16O target. The Dirac eikonal formalism is applied to account for the final-state interactions. The formalism is found to yield the response functions in good agreement with those calculated by the partial-wave expansion method at 0.515 GeV. We identify the response functions that depend on the spin-orbital potential in the final-state interactions, but not on the central potential. Dependence on the Dirac- or Pauli-type current of the nucleon is investigated in the helicity-dependent response functions, and the normal-component polarization of the knocked-out proton, $P_n$, is computed.Comment: 22 pages, Latex, figures available at ftp://ftp.krl.caltech.edu/pub/users/rseki/it

Dynamical breakdown of the Ising spin-glass order under a magnetic field

The dynamical magnetic properties of an Ising spin glass Fe$_{0.55}$Mn$_{0.45}$TiO$_3$ are studied under various magnetic fields. Having determined the temperature and static field dependent relaxation time $\tau(T;H)$ from ac magnetization measurements under a dc bias field by a general method, we first demonstrate that these data provide evidence for a spin-glass (SG) phase transition only in zero field. We next argue that the data $\tau(T;H)$ of finite $H$ can be well interpreted by the droplet theory which predicts the absence of a SG phase transition in finite fields.Comment: 4 pages, 5 figure

Time dependent spin-dressing using a 3^3He atomic beam

We have performed high precision experimental measurements of spin precession using a dressed $^3$He atomic beam. Spin-dressing uses an oscillating magnetic field detuned to high frequency which is orthogonal to a static magnetic field to effectively change the gyromagnetic ratio of a spin. We verify the validity of the spin-dressing Hamiltonian in regions beyond the limiting solution in which the Larmor frequency is much smaller than the frequency of the dressing field. We also evaluate the effect of magnetic field misalignment, e.g. if the oscillating magnetic field is not orthogonal to the static magnetic field. Modulation of the dressing field parameters is also discussed, with a focus on whether such a modulation can be approximated merely as a time dependent, dressed gyromagnetic ratio. Furthermore, we discuss implications for a proposed search for the neutron electric dipole moment, which would employ spin-dressing to make the effective $^3$He and neutron magnetic moments equal.Comment: 10 pages, 7 figure