15011888
Effect on cosmic microwave background polarization of coupling of quintessence to pseudoscalar formed from the electromagnetic field and its dual.
We present the full set of power spectra of cosmic microwave background (CMB) temperature and polarization anisotropies due to the coupling between quintessence and pseudoscalar of electromagnetism. This coupling induces a rotation of the polarization plane of the CMB, thus resulting in a nonvanishing B mode and parity-violating TB and EB modes. Using the BOOMERANG data from the flight of 2003, we derive the most stringent constraint on the coupling strength. We find that in some cases the rotation-induced B mode can confuse the hunting for the gravitational lensing-induced B mode.
14480613
Constraints on the dark energy equation of state from the separation of CMB peaks and the evolution of {alpha}
We introduce a simple parametrization of the dark energy equation of state, {omega}, which is motivated from theory and recent experimental data. The theory is related to the tracker solution to alleviate the fine-tuning problem. Recent experimental data indicates that the present value of {omega} is close to -1. We analyze the evolution of {omega} from the separation of CMB peaks and the time variation of the fine structure constant, {alpha}. We find that -1.00{<=}{omega}{sup (0)}{<=}-0.971{sub -0.027}{sup +0.017} and 1.76{sub -0.42}{sup +0.29}x10{sup -4}{<=}(d{omega}/dz){sub z=0}{<=}0.041{sub -0.037}{sup +=} 0{sup .016} at 95% confidence level.
54838721
Space charge effect on betatron oscillations
The transverse motion of the beam at the AGS was studied by analyzing the coherent beam signals, digitized at a 10 ns interval, at various beam intensities. It was found that the coherent vertical tune shift of the centroid is consistent with the space charge model due to the image charge and current induced on the vacuum chamber wall. An enhanced linear coupling at a high intensity was also observed.
118671237
Overlapping resonances and chaos in halo formation
The ‘‘particle‐core’’ model in the framework of Kapchinskij‐Vladimirskij (KV) distribution function approach is used in order to study dynamics of a test particle in a space charge dominated beam propagating through time‐dependent FOFO focusing channel. A simple analytical method is suggested in order to find a closed orbit solution for the envelope; the question about stability of small amplitude oscillations of weakly mismatched beam around the closed orbit solution is considered. The test particle motion is described by the methods of Hamiltonian dynamics; it is shown that a set of parametric resonances of the particle Hamiltonian can be generated by mismatched envelope oscillations in the time‐dependent focusing channel. It is demonstrated that the onset of global chaos in the particle phase space exhibits a sharp transition when the amplitude of envelope oscillations is larger than some critical value. Implications caused by the time dependence of the linear focusing field are discussed. The relation...
17171580
Emergence of classicality in quantum phase transitions
We show that classicality emerges during quantum phase transitions due to parametric interactions without coupling to environments. The Wigner functions are explicitly calculated for the Gaussian vacuum, number, and thermal states of a free scalar field that describes the spinodal instability regime. The Wigner functions are sharply peaked around their classical trajectories during the phase transition and exhibit classical correlation only for unstable long wavelength modes but retain quantum coherence for short wavelength modes. Thus classicality emerges from the quantum evolution of phase transitions without a classical order parameter. We define a quantal ordering parameter that is linear in the field variable and satisfies the classical field equation.
115801271
Space charge effect at transition energy and the transfer of rf system at top energy
Using 100 kV R.F. system, the beam loss due to transition crossing can be reduced to 1% for the phase space area of 0.3ev /center dot/ sec/amu. However the space charge effect would increase the phase space area to 1ev /center dot/ sec/amu after the transition energy. By using ..gamma../sub t/ jump or ..gamma.. increase, the phase space area can be preserved to 0.3ev /center dot/ sec/amu. To obtain small bunch length at the collision energy, we study the bunch rotation scheme. We find that the R.F. harmonic number should be less than 6 x 342 to obtain good efficiency and larger than 4 x 342 to reach experimental requirement. 5 refs., 13 figs., 2 tabs.
118451455
Non-Fermi liquid from a charged black hole: A critical Fermi ball
Using the anti-de Sitter/conformal field theory correspondence, we calculate a fermionic spectral function in a 2+1 dimensional nonrelativistic quantum field theory which is dual to a gravitational theory in the AdS{sub 4} background with a charged black hole. The spectral function shows no quasiparticle peak but the Fermi surface is still well-defined. Interestingly, all momentum points inside the Fermi surface are critical and the gapless modes are defined in a critical Fermi ball in the momentum space.