On the observability of the fieldB (3): Relativistic effects in magneto-optics

It is shown that the novel vacuum fieldB ⁽³⁾ is an experimental observable, and several methods of observation are suggested: these include the pulsed microwave magnetization of a plasma, the optical Aharonov-Bohm effect, and the microwave frequency optical Faraday effect. The effect ofB ⁽³⁾ is presented in the form of relativistically corrected semi-classical theory.     

A rapid-scan device for the determination of spectral line profiles in pulsed discharges

The results of a time-of-flight experiment are presented, in which the total cross-sections for 2–400 eV positrons on H₂, D₂, N₂, and CO were measured. Paper F7 presented at 3rd Internat'l. Conf. Positron Annihilation. Otaniemi, Finland (August 1973).     

Measurement of beam quality factor (M) by slit-scanning method

Beam quality factor (M²) and far-field scattering angle of LD end-pump Nd : YVO₄ laser were measured by slit-scanning method. The experimental results showed that the laser operated on a multi-mode state. The corresponding analytical treatments for slit-scanning method and M² factor measurement also were presented in this paper.     

Hadron spectroscopy at BABAR

The high integrated luminosity collected by the BABAR detector at the SLAC PEP-II e ⁺ e ^- B-Factory offers an excellent opportunity for the study of heavy-quark spectroscopy. A selection of the most recent results reported by BABAR will be presented, focussing on recently observed states with both open- and hidden-charm content.     

The problems with M

M² is now widely used to characterize the quality of laser radiation. In the paraxial approach the inequality M²1 holds, if M² is defined by the second moments. Nevertheless, in some publications M²<1 is presented, either theoretically or experimentally (Wang et al., Optik 1995;100(1):8; Lu et al., Optik 1995;100(2):91; Wang et al., Optics and Laser Technology 1999;31:151). In particular, it is stated that for a superposition of axially shifted Gaussian spherical beams, M² can become smaller than one (Wang et al., Optics and Laser Technology 1999;31:151). These problems with M² are briefly summarized.     

The E687 cryptoexotic vector meson candidate

A new study of the dip observed at 1.9GeV by the Fermilab experiment E687 in diffractive photoproduction of 3π ⁺3π ^- is presented. The E687 and the BABAR data on the annihilation cross-section σ(e ⁺ e ^-→3π ⁺3π ^-), obtained with initial-state radiation, are fitted all together. The fit function is based on a simple mixing mechanism that explains the manifestation of a resonance as a dip. Possible interpretations in terms of hybrids and tetraquark states are considered.     

Paracharge phenomenology: systematics of the new hadrons

A systematic semiquantitative account of all aspects of the strong and electromagnetic interactions of all the newly discovered hadronic states (theψ’s, theχ’s, etc.) is presented within the framework of the paracharge scheme. Extensions of ideas familiar from the SU₃ classification scheme to SU₄ are shown to provide an understanding of the new states seen in the decays ofψ (3.1) andψ′ (3.7), including their masses and gross decay characteristics. The decays ofψ (3.1) andψ′ (3.7) themselves are studied in some detail. Since these are of electromagnetic origin in the scheme, their electromagnetic mixing with the resonance at 4.15 GeV (theP-state of the scheme) is important. Once this is taken into account, the resulting picture is in excellent agreement with available data.     

J Coupling between C and H across Hydrogen Bonds in Proteins

Two new two- or three-dimensional NMR methods for measuring ^3hJ_C′N and ^2hJ_C′H coupling constants across hydrogen bonds in proteins are presented. They are tailored to suit the size of the TROSY effect, i.e., the degree of interference between dipolar and chemical shift anisotropy relaxation mechanisms. The methods edit 2D or 3D spectra into two separate subspectra corresponding to the two possible spin states of the ¹H^N spin during evolution of ¹³CO coherences. This allows ^2hJ_C′H to be measured in an E.COSY-type way while ^3hJ_C′N can be measured in the so-called quantitative way provided a reference spectrum is also recorded. A demonstration of the new methods is shown for the ¹⁵N,¹³C-labeled protein chymotrypsin inhibitor 2.     

金属氧化物半导体场效应管热载流子退化的1/fγ噪声相关性研究

研究了金属氧化物半导体(MOS)器件在高、中、低三种栅压应力下的热载流子退化效应及其1/f^γ噪声特性.基于Si/SiO₂界面缺陷氧化层陷阱和界面陷阱的形成理论,结合MOS器件1/f噪声产生机制,并用双声子发射模型模拟了栅氧化层缺陷波函数与器件沟道自由载流子波函数及其相互作用产生能级跃迁、交换载流子的具体过程.建立了热载流子效应、材料缺陷与电参量、噪声之间的统一物理模型.还提出了用噪声参数Sf ^{关键词： 金属氧化物半导体场效应管 热载流子 fγ噪声')" href="#">1/fγ噪声}     

Production of hypernuclei with the reaction

We present results on the production of bound states of Θ⁺ in nuclei using the (K⁺,π⁺) reaction. By taking into account the states obtained within a wide range of strength of the Θ⁺ nucleus optical potential, plus the possibility to replace different nucleons of the nucleus, we obtain an excitation spectra with clearly differentiated peaks. The magnitude of the calculated cross sections is well within reachable range.