Coexistence of self-organized criticality and intermittent turbulence in the solar corona

An extended data set of extreme ultraviolet images of the solar corona provided by the SOHO spacecraft is analyzed using statistical methods common to studies of self-organized criticality (SOC) and intermittent turbulence (IT). The data exhibit simultaneous hallmarks of both regimes: namely, power-law avalanche statistics as well as multiscaling of structure functions for spatial activity. This implies that both SOC and IT may be manifestations of a single complex dynamical process entangling avalanches of magnetic energy dissipation with turbulent particle flows.     

Asynchronous phase-modulated optical fiber-ring buffer

We investigate the dynamics of a 5-Gbit/s packet of ones and zeros loaded into a 0.5-kbit, phase-modulated optical fiber-ring buffer. A new mode of operation is explored in which the cavity length of the buffer is slightly detuned from the frequency driving the phase modulator. We examine the conditions for successful packet loading and the packet storage behavior. In addition, relaxation oscillations, which affected the storage time of previous high-speed optical ring buffers, are nearly eliminated with a cw holding beam, and significantly enhanced storage times are obtained.     

Parity-violating electron deuteron scattering and the proton's neutral weak axial vector form factor

We report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at backward angles at Q2=0.038 (GeV/c)2. This quantity provides a determination of the neutral weak axial vector form factor of the nucleon, which can potentially receive large electroweak corrections. The measured asymmetry A=-3.51+/-0.57 (stat)+/-0.58 (syst) ppm is consistent with theoretical predictions. We also report on updated results of the previous experiment at Q2=0.091 (GeV/c)2, which are also consistent with theoretical predictions.     

Quark-hadron duality in neutron (3He) spin structure

We present experimental results of the first high-precision test of quark-hadron duality in the spin-structure function g_{1} of the neutron and 3He using a polarized 3He target in the four-momentum-transfer-squared range from 0.7 to 4.0 (GeV/c);{2}. Global duality is observed for the spin-structure function g_{1} down to at least Q;{2}=1.8 (GeV/c);{2} in both targets. We have also formed the photon-nucleon asymmetry A1 in the resonance region for 3He and found no strong Q2 dependence above 2.2 (GeV/c);{2}.     

Study of transverse momenta of charged hadrons produced in νp and\bar vp charged current interactions

Data from a neutrino and antineutrino hydrogen experiment with BEBC are used to investigate transverse properties of the produced charged hadrons. Measurements are presented on average transverse momenta of charged pions as functions of Feynman-x and the hadronic mass, on the transverse momentum flow within an event and on jet-related quantities. The main features of the data are well described by the LUND model. The data favour a version of the model in which soft gluon effects are included and the primordial transverse momentum of the quarks in the proton is small. Effects from 1^st order QCD (hard gluon emission) are negligible.     

Subnanosecond high-pressure iodine photodissociation laser oscillator

A simultaneously Q-switched and acousto-optic mode-locked high-pressure iodine photodissociation (=1.315m) oscillator system, capable of generating pulse-widths as short as 160 ps is described. Good agreement is found between theory and experiment for the pressure-dependence of the modelocked pulse-width. The results indicate that pulse-widths approaching 100ps should be obtainable with this type of system.     

Infrared and microwave spectra, molecular conformation and electric dipole moment of methyl thiolformate

The microwave spectrum (41-10 GHz) and the infrared spectrum (4000-50 cm⁻¹) of methyl thiolformate have been obtained and analyzed. The spectra are consistent with a single molecular conformation having a planar array of heavy atoms and with the alkyl group cis to the carbonyl group. The measured rotational constants are: A, 11042.22 MHz; B, 5118.27 MHz; C, 3562.03 MHz (κ = −0.5839). No internal rotation doublets were observed in the microwave spectrum for the ground vibrational state, which implies that the barrier hindering internal rotation of the methyl group is either much larger or much smaller than the corresponding value for methyl formate. If the former is true then a lower limit of 10.5 kJ mol⁻¹ may be placed on the barrier height.The dipole moment of methyl thiolformate was measured using the Stark effect to be 1.58 ± 0.05 Debyes (μ_A = 1.52 D; μ_B = 0.43 D) for the vapor, and for dilute solutions in benzene at 295 K the value of 1.6 ± 0.1 D was found from capacitance measurements.SCF computations using minimal basis sets of STO/3G atomic orbitals and extended basis sets of STO/4.31G atomic orbitals have been carried out for methyl thiolformate and methyl formate. Energy differences between rotational isomers and estimates of barrier heights are given together with the calculated dipole moments.