[en] Relativistic corrections of order α² to the decay width of orthopositronium are calculated using the local quasipotential equation. Necessary contributions coming from the amplitude of the three-photon decay of orthopositronium and from the normalization of the wave function, as well as second-order perturbative corrections, are taken into account. 20 refs., 2 figs

[en] This paper deals with the orthoprojection widths of classes of periodic functions of two variables with a given majorant of the mixed moduli of continuity of order l that contains logarithmic factors as well as powers. In several cases we find the exact orders of the orthoprojection widths of these classes of functions

[en] A general upper bound is obtained for the nonexponential contribution to the time-dependent occupation amplitude G(t) for an autoionizing state just above the continuum threshold in the limit of narrow widths. This upper bound is shown to be inconsistent with some recently published results predicting new observable nonexponential effects in Vertical BarG(t)Vertical Bar², but is consistent with earlier long-accepted theory. It is also shown how some nonexponential contributions to the decay might, in principle, still occur as a consequence of close proximity between the autoionizing state and the ionic threshold, although these contributions now have a different form than those recently proposed

[en] New quantum-mechanical (QM) and semi-classical (SC) shifts (d's) and widths (HWHM's, w's) were measured from the line core of computed full spectral-line shapes for the Ar-perturbed/K-radiator system (K/Ar). The initial state of our model was based on a 4p ² P _3/2,1/2 pseudo-potential for the K/Ar system, and the final state on a zero potential. The Fourier transform of the line shape formed the basis for the computations. Excellent agreement was found between the QM and SC values of d and of w in a high-pressure (P) non-impact region, which was characterized by a √P dependence of w and a P dependence of d. These agreements were shown to be another example of a correspondence between classical (SC) quantities and QM quantities in the limit of large quantum numbers. Typically at P=1x10⁶ Torr and T=400 K, w_QM=448 cm^-1 and w_SC =479 cm^-1, where the deviation from the mean is ±3.3%. Also, d_QM =-3815 cm^-1 and d_SC =-3716 cm^-1, where the deviation from the mean is ±1.3%. A new general method was formulated which yielded a definite pressure P ₀, which was defined as an upper limit to the low-pressure impact approximation and a lower limit to the non-impact region

[en] We calculate decay widths of the metastable ppμ_ν,J^* molecular ion in non-adiabatic approach. The muonic molecular ion can be formed in collision of the excited pμ(2s) atoms with H₂. Then, the decay of the ppμ_ν,J^* system opens a path for the muon from pμ(2s) to pμ(1s). We employ trial wave function which includes non-adiabatic terms to calculate some radiationless decay widths. The present results of the widths do not agree well with those given in our previous work, however they are more close to recent data of other researchers. (author)

[en] The heavy-fermion superconductor CeCu₂Si₂ is located close to a quantum critical point. The spin fluctuations at the nesting wave vector Q_AF in the normal state are quasielastic and show considerable slowing down. The magnetic response also exhibits scaling expected for a 3D spin-density-wave quantum critical point. We present here the first measurement of the momentum dependence of these almost quantum critical fluctuations. The temperature dependence of the linewidth of the spin fluctuations in reciprocal space is studied and compared to theoretical expectations, which arise from the connection of momentum width and energy width via the dynamical critical exponent z.

[en] Using a semiclassical approach, we have calculated electron-, proton-, and ionized-argon-impact line widths and shifts for 24 Rb I multiplets. The resulting data have been compared with existing experimental and theoretical values. (orig.)

No abstract available

[en] Using the hitherto unprecedented quantity of about 500 values of each of the electrojet parameters derived from the POGO data, it has been found from a study of the relation between the current and width of the electrojet that from about a couple of hours before to about a couple of hours after local noon, the width of the equatorial 2 w km, decreases as the peak eastward current intensity J₀ A km^-1 or the total eastward current Isub(+), of the electrojet increases, and that certain lower limits of intensity and total current appear to be necessary before the constriction of the width commences. It is suggested that the constriction arises from the pinch effect in plasmas exposed to magnetic field, and that since such plasmas are unstable and break up into lumps of plasma, this should make some contribution to the production of some equatorial electrojet irregularities. (author)

[en] Objective: To observe the CT findings of hypoplasia of cochlear nerve foramen. Methods: CT findings of cochlear nerve foramen were observed in 50 volunteers (100 ears) and in 9 cases with hypoplasia of cochlear nerve foramen. The width of the bony canal for the cochlear nerve were measured in both groups. Results: The fissure in the cribriform area were seen in every, volunteers. The width of the bony canal for the cochlear nerve was (2.32 ± 0.25) mm in normal group. The stenosis of cochlear nerve foramen were shown in 9 eases (10 ears), the lacking of fissure in the cribriform area were seen in 8 ears, while the fissure were shown in 2 cases. The stenosis of internal auditory canal was shown in 4 cases. Abnormality of vestibule and horizontal semicircular canal was shown in one case. The maximum value of the width of the bony canal for the cochlear nerve was 1.5 mm, the minimum value was 0.9 mm. Conclusions: The typical CT findings of hypoplasia of cochlear nerve foramen were stenosis of cochlear nerve foramen, the lacking of fissure in the cribriform area and cochlear nerve foramen without helix shape. The hypoplasia of cochlear nerve foramen may be a subtype of cochlear dysplasia. (authors)