Quantum systems in weak gravitational fields

Fully covariant wave equations predict the existence of a class of inertial-gravitational effects that can be tested experimentally. In these equations inertia and gravity appear as external classical fields, but, by conforming to general relativity, provide very valuable information on how Einstein's views carry through in the world of the quantum.Comment: 22 pages. To be published in Proceedings of the 17th Course of the International School of Cosmology and Gravitation "Advances in the interplay between quantum and gravity physics" edited by V. De Sabbata and A. Zheltukhin, Kluwer Academic Publishers, Dordrech

Quantum physics in inertial and gravitational fields

Covariant generalizations of well-known wave equations predict the existence of inertial-gravitational effects for a variety of quantum systems that range from Bose-Einstein condensates to particles in accelerators. Additional effects arise in models that incorporate Born reciprocity principle and the notion of a maximal acceleration. Some specific examples are discussed in detail.Comment: 25 pages,1 figure,to appear in "Relativity in Rotating Frame

The effect of an NgR1 antagonist on the neuroprotection of cortical axons after cortical infarction in rats

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Undrained cyclic response of K-0-consolidated stiff cretaceous clay under wheel loading conditions

Optimal whole life design for railways, highways, runways, and metro lines requires an accurate assessment of how their underlying geomaterials respond to large numbers of wheel-loading cycles. This paper presents an experimental study on a natural UK stiff clay with a cyclic triaxial (CT) and hollow cylinder apparatus (CHCA) that imposed K0 and wheel-loading stress conditions. The focus is on Gault clay, a high overconsolidation ratio (OCR) marine clay deposited in the Cretaceous, whose mechanical behavior is significantly anisotropic and in situ K0 values exceed unity. The clay outcrops under sections of most major highways radiating out of London, as well as the HS1 and new HS2 high-speed railways. The experimental investigation explored how the principal stress rotation implicit in wheel loading increases the magnitudes and changes the sign of vertical strain accumulation, as well as accelerating resilient modulus degradation and accentuating stress–strain hysteresis, all of which affect pavement or rail-track serviceability. The clay’s deformation and pore pressure responses are categorized into stable, metastable, and unstable patterns. Comparisons with related studies on low OCR, low K0 soft clay from Wenzhou in southeastern China, confirm the Gault clay’s generally stiffer prefailure behavior and different cyclic response. The stiff clay’s greater brittleness is also emphasized; particle reorientation occurs readily along distinct shear bands, leading to dramatic shear strength reductions that have a major impact on slope and foundation stability and call for appropriate caution in practical design

Direct immobilization of phosphine-rhodium complex on MCM-41 for propene hydroformylation

MCM-41 molecular sieve supported Rh-PPh3 catalysts were prepared by the in-situ assembling of the metal complex from smaller moieties of Rh(acac) (CO)(2) and ligand of PPh3. The resulted guest/host materials (Rh-PPh3/MCM-41) were characterized by X-ray powder diffraction, FTIR and P-31 (H-1.) NMR, and served as catalysts for propene hydroformylation. The results showed negligible change in MCM-41 framework after propene hydroformylation at 393 K. Higher hydroformylation activities were obtained on Rh-PPh3/MCM-41 catalysts compared to that on Rh-PPh3/SiO2,

Resonances in J/ψ→ϕπ+π−J/\psi \to \phi \pi ^+\pi ^- and ϕK+K−\phi K^+K^-

A partial wave analysis is presented of $J/\psi \to \phi \pi ^+\pi ^-$ and $\phi K^+K^-$ from a sample of 58M $J/\psi$ events in the BES II detector. The $f_0(980)$ is observed clearly in both sets of data, and parameters of the Flatt\' e formula are determined accurately: $M = 965 \pm 8$ (stat) $\pm 6$ (syst) MeV/c$^2$, $g_1 = 165 \pm 10 \pm 15$ MeV/c$^2$, $g_2/g_1 = 4.21 \pm 0.25 \pm 0.21$. The $\phi \pi \pi$ data also exhibit a strong $\pi \pi$ peak centred at $M = 1335$ MeV/c$^2$. It may be fitted with $f_2(1270)$ and a dominant $0^+$ signal made from $f_0(1370)$ interfering with a smaller $f_0(1500)$ component. There is evidence that the $f_0(1370)$ signal is resonant, from interference with $f_2(1270)$. There is also a state in $\pi \pi$ with $M = 1790 ^{+40}_{-30}$ MeV/c$^2$ and $\Gamma = 270 ^{+60}_{-30}$ MeV/c$^2$; spin 0 is preferred over spin 2. This state, $f_0(1790)$, is distinct from $f_0(1710)$. The $\phi K\bar K$ data contain a strong peak due to $f_2'(1525)$. A shoulder on its upper side may be fitted by interference between $f_0(1500)$ and $f_0(1710)$.Comment: 17 pages, 6 figures, 1 table. Submitted to Phys. Lett.

Measurement of the Branching Fraction of J/psi --> pi+ pi- pi0

Using 58 million J/psi and 14 million psi' decays obtained by the BESII experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous measurements.Comment: 9 pages, 8 figures, RevTex

Search for K_S K_L in psi'' decays

K_S K_L from psi'' decays is searched for using the psi'' data collected by BESII at BEPC, the upper limit of the branching fraction is determined to be B(psi''--> K_S K_L) < 2.1\times 10^{-4} at 90% C. L. The measurement is compared with the prediction of the S- and D-wave mixing model of the charmonia, based on the measurements of the branching fractions of J/psi-->K_S K_L and psi'-->K_S K_L.Comment: 5 pages, 1 figur

First observation of psi(2S)-->K_S K_L

The decay psi(2S)-->K_S K_L is observed for the first time using psi(2S) data collected with the Beijing Spectrometer (BESII) at the Beijing Electron Positron Collider (BEPC); the branching ratio is determined to be B(psi(2S)-->K_S K_L) = (5.24\pm 0.47 \pm 0.48)\times 10^{-5}. Compared with J/psi-->K_S K_L, the psi(2S) branching ratio is enhanced relative to the prediction of the perturbative QCD ``12%'' rule. The result, together with the branching ratios of psi(2S) decays to other pseudoscalar meson pairs (\pi^+\pi^- and K^+K^-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.Comment: 5 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let