Modern Physics Letters A

The increase in the accuracy of Doppler measurements in space requires a rigorous definition of the observed quantity when the propagation occurs in a moving, and possibly dispersive medium, like the solar wind. This is usually done in two divergent ways: in the phase viewpoint it is the time derivative of the correction to the optical path; in the ray viewpoint the signal is obtained form the deflection produced in the ray. They can be reconciled by using the time derivative of the optical path in the Lagrangian sense, i.e. differentiating from ray to ray. To rigorously derive this result an understanding, through relativistic Hamiltonian theory, of the delicate interplay between rays and phase is required; a general perturbation theorem which generalizes the concept of the Doppler effect as a Lagrangian derivative is proved. Relativistic retardation corrections O(v) are obtained, well within the expected sensitivity of Doppler experiments near solar conjunction.

The equation of perfect dilaton-spin fluid motion in the form of generalized hydrodynamic Euler-type equation in a Weyl–Cartan space is derived. The isoentropic character of perfect dilaton-spin fluid motion is established. The equation of motion of a test particle with spin and dilatonic charge in the Weyl–Cartan geomtry background is obtained. The peculiarities of test particle motion in a Weyl–Cartan space are discussed.

A particle in quantum mechanics on manifolds couples to the induced topological gauge field that characterizes the possible inequivalent quantizations. For instance, the gauge potential induced on S² is that of a magnetic monopole located at the center of S². We find that the gauge potential induced on S³(S^{2n+ 1}) is that of a meron (generalized meron) also sitting at the center of S³(S^{2n+ 1}).

The two-body nonleptonic Λ_b decays are considered in the HQET with 1/m_Q corrections and factorization approximation. The Isgur–Wise function is evaluated in the bound state soliton picture. The results obtained remain well below their previously predicted upper limit.

Quasiclassical solution of the three-dimensional Schrödinger's equation is given. It is shown apparently that the exitence of nonzero minimal angular momentum M₀=ℏ/2 corresponds to the quantum fluctuations of the angular momentum and contributes to the energy of the ground state.

Fisher's arrow of "time" in a cosmological phase space defined as in quantum optics (i.e. whose points are coherent states) is introduced as follows. Assuming that the phase space evolution of the universe states from an initial squeezed cosmological state towards a final thermal one, a Fokker–Planck equation for the time-dependent, cosmological Q phase space probability distribution can be written down. Next, using some recent results in the literature, we derive an information arrow of time for the Fisher phase space cosmological entropy based on the Q-function. We also mention the application of Fisher's arrow of time to stochastic inflation models.

Using a unified and systematic scheme, the free field realization of irreducible representations of osp(2|2) is constructed. By using these realizations, the correlation functions of N = 2 superconformal model based on osp(2|2) symmetry and free field representation of generators are calculated. Free field representation of currents are used to determine the stress-energy tensor and the central charge of the model.

A relativistic quark potential model is used to do a systematic search for quasi-stable dibaryon states in the u, d and s three-flavor world. Flavor symmetry breaking and channel coupling effects are included and an adiabatic method and fractional parentage expansion technique are used in the calculations. The relativistic model predicts dibaryon candidates completely consistent with the nonrelativistic model.

The spin fractions and deep inelastic lepton structure functions of the proton are analyzed based on chiral field theory invloving Goldstone bosons. A detailed comparison with several recent chiral models sheds light on their successful description of the spin fractions of the proton as being due to neglecting quark masses. Initial quark valence distributions at a higher scale than Λ_QCD are constructed using quark counting constraints at large Bjorken x→1 and Regge behavior at small x. Reasonable strange quark distributions are then predicted by chiral field theory. The spin fractions also agree with the data.