An anomalous M1 transition in 38Cl

The observed enchangement of the M1 transition in ³⁸Cl between the 3^? state of the “$\text{d}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{-}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ multiplet” and the 4^? state of the “ mumultiplet” is explained.     

Kinematical scale breaking in high pT interactions

Assuming scaling in the longitudinal reduced momentum in the overall c.m. for the parton fragmentation function, there are, in any hard scattering model, at least three possible sources of a lack of scaling in $\text{(}\text{1}\text{σ}\text{)}\text{d}\text{σ}\text{d}\text{x}{}_{\mathrm{<mtext>e</mtext>}}$. In this paper we analyse these causes emphasising one of them, “the skew mechanism”, which occurs because the axes of the partons are not the x-axis used to express the reduced momenta of the hadrons and because, simultaneously, the transverse momentum of hadrons inside partons is not negligible. A particular result of our study is that the lack of scaling in $\text{(}\text{1}\text{σ}\text{)}\text{d}\text{σ}\text{d}\text{x}{}_{\mathrm{<mtext>e</mtext>}}$ observed by CCHK and BFS collaborations is not necessarily in contradiction with the scaling in the longitudinal reduced momentum of the jet.     

Activation energy of field emission flicker noise power due to adsorbed potassium on tungsten

The temperature dependence of the field emission flicker noise spectral density functions has been investigated for potassium adsorbed on tungsten (112) planes by a probe hole technique. By integration of the spectral density functions $\text{W(?) = B}{}_{\mathrm{i}}\text{?}{}^{\mathrm{?ge}}\text{i}$ the noise power $\text{(δn}{}^2{}_{\mathrm{\Delta ?}}$ for different frequency intervals Δ? is obtained. From the exponential temperature dependence of $\text{(δn}{}^2{}_{\mathrm{\Delta ?}}$ noise power “activation energies” q_Δ? are determined. Plots of these energies versus coverage show a similar “oscillating” behaviour as recently found for $\text{W(?}{}_{\mathrm{j}}\text{)}$ or which indicates phase transitions of the adsorbed potassium submonolayers. The noise activation energies are discussed in terms of existing models and a comparison is made between the experimental q values and surface diffusion energies E_d as determined by conventional methods.     

Anomalous electron thermal conductivity across the destroyed magnetic surfaces

New “Semicollisional” regime of the anomalous electron transport pertaining to the weakly collisional plasma is described in the paper. The transition from the collisionless to semicollisional case is determined by the ratio of the phase stochastization length of the parallel electron motion to the mean free path. It was shown also that the anomalous thermal conductivity can be described by the known “selfsimilar” expression $\text{χ}{}_{\mathrm{?}}\text{= χ}{}_{6e}\text{Ь}{}^2{}_0$ only for very strong collisions or high level of magnetic field turbulence.     

The (p, 2p) reaction on 6Li

The differential cross section for the quasi-elastic scattering of protons on ⁶Li is derived in the impulse approximation. The nucleus ⁵He is not treated as a bound nucleus in the derivation. Instead, the n-α interactions $\text{s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, $\text{P}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$, $\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ and $\text{d}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ in the final state are included. Fits to the unknown vertex functions appearing in the expression obtained for the momentum distribution at the “ground state” of ⁵He are given, showing that the n-α $\text{s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ interaction is important at the “ground state” of ⁵He. The consistency between the observed momentum distribution and the ⁶Li form factor at low momentum transfers is shown utilizing Elton's model.     

Asymptotic power laws for hadron calorimeter experiments

This is a study of asymptotic QCD predictions for collisions in which a finite fraction of the available energy is carried by hadrons into an angular region $\text{Ω}$ whose complement is $\text{Ω}{}_{\mathrm{<mtext>a</mtext>}}$ or $\text{Ω}{}_{\mathrm{<mtext>b</mtext>}}$ or $\text{Ω}{}_{\mathrm{<mtext>a</mtext>}}\text{UΩ}{}_{\mathrm{<mtext>b</mtext>}}\text{, Ω}{}_{\mathrm{<mtext>a</mtext>}}$ being fixed cones about the directions of motion of the initial particles. Apart from slow (logarithmic) corrections the asymptotic power laws derived from the covariant parton model appear to be justified provided certain conditions on $\text{Ω}{}_{\mathrm{<mtext>a</mtext>}}$ and/or $\text{Ω}{}_{\mathrm{<mtext>b</mtext>}}$ and the energy deposited in them are met.     

On the semileptonic decay of charmed hadrons

The semileptonic and leptonic decay modes of charmed hadrons produced in e⁺e^? collisions above 4 GeV in the cm have been investigated by selecting events with a single electron plus at least two charged tracks. The electron momentum spectrum peaks near 0.5 GeV/c with few events above 0.7 GeV/c. The spectrum excludes large rates for the decays $\text{D}\text{→}\text{e}\text{v}{}_{\mathrm{<mtext>e</mtext>}}$ and $\text{D}\text{→}\text{e}\text{v}{}_{\mathrm{<mtext>e</mtext>}}\text{π}$, but is compatible with $\text{D}\text{→}\text{e}\text{v}{}_{\mathrm{<mtext>e</mtext>}}\text{K}{}^1\text{(892)}$, $\text{D}\text{→}\text{e}\text{v}{}_{\mathrm{<mtext>e</mtext>}}\text{K}$ or a mixture of both. The semileptonic branching ratio is obtained both by comparing the inclusive electron cross section with the total cross section attributable to charm, and by studying the fraction of events containing a second electron. The semileptonic charm branching ratios obtained are 0.11 ± 0.03 and 0.16 ± 0.06 respectively. A single event with three electrons and hadrons is found, consistent with the estimated background. The 90% confidence upper limit for σ(e⁺e^? → 3e + hadrons) is 0.1 nb.     

Computer simulation of collective phenomena in a turbulent plasma

A short review of the results of one- and two-dimensional computer investigations of strong Langmuir turbulence is given. The main topics of interest are the following: formation of high energetic electron tails; ion sound turbulence accompanying collapse and plasmons' conversion; modulation instability (MI) in X,Y-geometry for $\text{T}{}_{\mathrm{e}}\text{T}{}_{\mathrm{i}}\text{? 1}$ and $\text{T}{}_{\mathrm{e}}\text{T}{}_{\mathrm{i}}\text{?1}$; MI in transverse magnetic field. The case of the “forced” collapse (quasicollapse) in presence of an external pump $\text{E}{}_{\mathrm{<mtext>ext</mtext>}}\text{=}\text{E}{}_{\mathrm{<mtext>ox</mtext>}}\text{Cos}\text{ω}{}_{\mathrm{o}}\text{t}$ is considered.     

High-pt hadrons in the pionization region in QCD

We show that in QCD the production of high-p_t hadrons in the pionization region $\text{ln}\text{(}\text{p}{}_{\mathrm{<mtext>t</mtext>}}{}^2\text{μ}{}^2\text{) < [(}\text{8N}\text{D0.21 β}{}_2\text{)}\text{ln}\text{x}{}^{\mathrm{?1}}\text{]}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ is not a rare process, but a usual “soft” one. Its inclusive cross section ? behaves as $\text{? =}\text{d}\text{σ}\text{d}\text{y}\text{d}\text{p}{}_{\mathrm{<mtext>t</mtext>}}{}^2\text{∝}\text{σ}{}_{\mathrm{<mtext>t</mtext>}}\text{p}{}_{\mathrm{t0}}{}^2$. At ISABELLE energies and p_t = 10 GeV we estimate this cross section to be at least an order larger than the value obtained by commonly used parametrizations.     

High energy electronic neutrino (ve) and antineutrino (ve) interactions

The total cross-sections for $\text{v}{}_{\mathrm{<mtext>e</mtext>}}\text{(}\text{v}{}_{\mathrm{<mtext>e</mtext>}}\text{)}$-nucleon scattering have been measured. A test has been made of the muon number conservation law. A limit of 2.4 GeV is found the mass of the “Georgi-Glashow type” heavy lepton     

Microwave spectrum and hydrogen bonding in 1-aziridineethanol

From its microwave spectrum, 1-aziridineethanol,

$\text{CH}{}_2\text{CH}{}_2\text{NCH}{}_2\text{CH}{}_2\text{OH}$

is found to have a gauche OCCN configuration, maintained by an OH?N-type hydrogen bond. The normal species rotational constants (MHz), A = 8528.87(25), B = 2069.74(2), and C = 2020.41(2), are consistent with a small (～6°) distortion from the “staggered” configuration about the central CN bond. Assuming a “normal” hydroxyl group, the hydroxy d₁ data suggest a decrease in the O?N distance upon bridge deuteration of ～0.003 Å. The dipole moment is 2.77(5) D, with 2.34(3), 1.45(6), and 0.3(3) D “a,” “b,” and “c” components, respectively.     

The Miura transform and the existence of an infinite number of conservation laws of the cylindrical KdV equation

The cylindrical KdV equation, $\text{u}{}_{\mathrm{t}}\text{+ 6uu}{}_{\mathrm{x}}\text{+ u}{}_{\mathrm{xxx}}\text{+}\text{u}\text{2t}\text{= 0}$, is investigated. The Miura transform is obtained by a simple new method based on a “closedness” ansatz. By use of the obtained Miura transform, an infinite number of conservation laws are proved to exist.     

Lattice formulation of the CPn−1 non-linear σ models

We set up a general lattice version of non-linear σ models defined on homogeneous spaces. We then apply this to the CP^n?1 models which are the correct extension of the SU(2) σ model to SU(N). We exhibit their “confinement” property: the elementary multiplets Z_α used to describe the system do not appear as physical particles but only as bound states $\text{Z}{}_{\mathrm{\alpha }}\text{λ}{}_{\mathrm{\alpha \beta }}{}^{\mathrm{a}}\text{Z}{}_{\mathrm{\beta }}$. The method enable us to examine the “θ vacua” in the strong coupling limit by using a “dilute loop” approximation. We discuss the effect of the low activation energy for instantons which means that on a lattice, topological number is not conserved.     

Monte Carlo simulation of a three-dimensional spin glass

Similarly to two dimensions, the Edwards-Anderson model of (Ising) spins with a Gaussian nearest-neighbor exchange-force distribution gives near $\text{T}{}_{\mathrm{<mtext>c</mtext>}}\text{≈1.5}\text{ΔJ}\text{k}{}_{\mathrm{<mtext>B</mtext>}}$ a cusp in the susceptibility, a peak in the specific heat, and a continuous vanishing of the “order parameter”.     

A numerical estimate of deviations from the exponential decay law for the transition 2P12→1S12 in hydrogen

The deviations from the exponential decay law of the $\text{2}\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ states of the Dirac hydrogen atom with respect to the transition $\text{2}\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{→1}\text{S}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ are numerically estimated. We find |a₀(t) ? exp(?λt)|?2.5 × 10^?4 for all t, where a₀(t) is the “exact” decay amplitude and λ is a complex constant such that (2Re λ)^?1 is the “natural lifetime” of the $\text{2}\text{P}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ states with respect to the spontaneous transition to $\text{1}\text{S}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$.     

Multiplicity distributions and double-scattering effects in π−d interactions at 360 GeV/c

Double-scattering effects are studied in π^?d interactions at 360 GeV/c. The partial cross sections $\text{σ}{}_{\mathrm{<mtext>N</mtext>}}\text{(π}{}^{\mathrm{?}}\text{d}\text{), σ}{}_{\mathrm{<mtext>N</mtext>}}\text{(“π}{}^{\mathrm{?}}\text{p}\text{”)}\text{and}\text{σ}{}_{\mathrm{<mtext>N</mtext>}}\text{(“π}{}^{\mathrm{?}}\text{n}\text{”)}$ are presented. The double-scattering probability per πd collision is found to be $\text{? = 0.15 ± 0.02}$. We have extracted the partial cross section X_N of the double-scattering plus interference contributions, and find that X_N obeys KNO scaling. The data are compared with various theoretical predictions.     

Influence of Coriolis anti pairing and alignment on the rotational states in nuclei

The inclusion of both Coriolos anti pairing (CAP) and alignment in the simple $\text{i}{}_{\mathrm{<mtext>13</mtext><mtext>2</mtext>}}$ model is studied. It is found that “backbending” occurs for too small angular frequencies in such a model.     

Functional derivative δTc/δα2 (Ω)F(Ω) for weak coupling superconductors

We present approximate analytic calculation of the functional derivative $\text{δT}{}_{\mathrm{c}}\text{δα}{}^2\text{(Ω)F(Ω)}$, where T_c is the superconducting critical temperature and $\text{α}{}^2\text{(Ω)F(Ω)}$ is the electron-phonon spectral function, within the “square-well model” for the phonon mediated electron-electron interaction and weak coupling limit $\text{ω}{}_{\mathrm{D}}\text{(2πT}{}_{\mathrm{c}}\text{)? 1 (ω}{}_{\mathrm{D}}$ is the Debye energy). It is found that $\text{δT}{}_{\mathrm{c}}\text{δα}{}^2\text{(Ω)F(Ω) = (1 + λ)}{}^{-1}\text{G(Ω)}$ where λ is the familiar electron-phonon coupling parameter and $\text{G(Ω)}$ is a universal function of the reduced frequency $\text{Ω}\text{=}\text{Ω}\text{T}{}_{\mathrm{c}}$. We compare this formula with accurate numerical results for several weak coupling superconductors. The overall agreement is good     

Spin dynamics in the quasi-1 dimensional spin-glass FeMgBo4

The results of an inelastic neutron scattering investigation performed on the insulating title compound are presented. The spin dynamic is well described by a relaxation model leading to a quasi-elastic Lorentzian neutron-scattering line. The relaxation rate $\text{1}\text{τ}{}_{\mathrm{R}}$ is a linear temperature function for T>20 K, which is ascribed to the isotropic and 1-D character of the spin correlations. At T = 20 ? 5 K a drastic drop in $\text{1}\text{τ}{}_{\mathrm{R}}$ is observed reflecting a “crossover” to a highly frustrated 3D-spin glass state.     

Johnson noise and absolute temperature

Experimental evidence using Josephson junction devices has suggested that Johnson noise in copper fails to be proportional to absolute temperature below 10 millikelvin. A microscopic theory is presented which gives the Johnson noise temperature $\text{T}{}_{\mathrm{<mtext>J</mtext>}}\text{= ?}{}_0{}^1\text{XT}{}_0$ coth ($\text{XT}{}_0\text{T}$) dX where $\text{T}{}_0\text{=}\text{hν}{}_{\mathrm{<mtext>F</mtext>}}\text{2kN}$. For copper, the calculated T₀ = 3.84 mK agrees closely with the value extracted from experimental data, 3.89 mK. Within a few percent, $\text{T}{}_{\mathrm{<mtext>J</mtext>}}\text{? (}\text{T}{}_0\text{2}\text{)}$ coth ($\text{T}{}_0\text{2T}$), and this adequately fits the available experimental data. ν_F is the fermi velocity and N is the length of the resistor. The Johnson noise parameter “T₀” presumably can measure ν_F along different crystal orientations.