A new approach to the problem of the anomalous magnetic moment of the electron

A heuristic model for deriving the anomalous magnetic moment of the electron is presented. A term /2 – 0.327(/)² is deduced, in better agreement with experiment than is the QED derivation of /2 – 0.328(/)². The result is strengthened by the recent non-QED account of the Lamb shift by Yu and Sachs.     

The effect of low-temperature electron irradiation on the transition temperature of YBa2Cu3O7−δ superconductors

Measurements of the complex susceptibility =–i of electron-irradiated YBa₂Cu₃O_7– show a strong influence of the electron irradiation dose, ·t on the transition temperatureT _c . For irradiation doses of ·t=2.2·10¹⁹ e^–/cm² we find a damage rate of T _c /(·t)=–1.6·10^–19 K/(e^–/cm²). It is assumed that the decrease ofT _c is mainly a bulk effect due to the production of atomic defects like vacancies and interstitials in the Cu–O–Cu chains and in the basal planes of the unit cells.     

Fine Structures of the Permittivity and Characteristic Losses of Electrons in Fluorite

Experimental-computational spectra of the permittivity and characteristic losses –Im^–1 for energies in the range 5–21 eV at a temperature of 4.2 K and theoretical spectra of and –Im^–1 of a fluorite crystal are resolved into elementary transition bands. The parameters of transition bands (energies of their maxima E _i, band halfwidths H _i and areas S _i, and oscillator forces f _i) are determined. A correlation of the spectral bands of and –Im^–1is established, and their specific features are elucidated.     

How to measure the magnetic moment of the tau lepton

We present a method for obtaining bounds on the magnetic moment of the lepton. In order to do this, we study the radiative decayW as a function of the anomalous magnetic moment of the ,a . One can obtain bounds as good asa < 4.05×10^–2, 2.25×10^–2, 4.5×10^–3, and 2.5×10^–3 at the present Fermilab, future Fermilab, SSC, and LHC, respectively.     

High-frequency expansion of relativistic classical plasma dielectric tensor

A high-frequency sum-rule expansion is derived for the transverse elements of the relativistic classical plasma dielectric tensor in an isotropic system. The relativistic results are different from the nonrelativistic ones by a factor of ^–1(1 – ²/3c ²) for ₂ (k) and longitudinal plasmon and transverse photon frequencies, and by ^–2(1–2 ²/3c ²) for ₂ (k).     

Pulsations and chaos in laser-produced plasmas

A general criterion is proposed predicting the onset of chaotic behavior for parametric processes in a laser-produced plasma. The conditions when the transition to the stochastic regime occur are determined for various parametric instabilities excited when a high intensity laser interacts with a plasma. The complicated temporal structure observed in 3/2₀, 2₀, 1₀, and fast electron emission in experiments using high-intensity (I10^15–17 W/cm²), short ( _L 40–200 psec) Nd laser pulses is attributed to the reflection seeded SBS instability being driven into this regime.Lebedev Physics Institute, Leninsky Prospect 53, Moscow 117924 Russia.     

Energy spectrum and angular distribution of muons from the decay of heavy leptons produced in colliding electron-positron beams

On the basis of an arbitrary (V, A) structure of the neutral weak ¯ee and LL currents (L=^–, M⁰) a study is made of the processes of production in colliding electron-positron beams of pairs of heavy leptons with subsequent decays in accordance with the schemes e⁺e^––(µ^–v_µv) + ⁺( anything) and e⁺e^–M⁰(µ^–e⁺v_e) + M⁰( anything). The energy spectrum and asymmetry of the distribution of the produced muons are investigated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 66–70, February, 1981.     

Laser damage in silicon photodiodes

Thermal damage of silicon photodiodes exposed to intense optical radiation is investigated. Damage thresholds of Si photodiodes irradiated by 1.06m laser pulses are reported for values of irradiation time,, ranging from 10^–8 to 1s. Threshold laser irradiation produces visible microscopic damage and a permanent degradation in photoresponse. The loss of responsivity is associated with degradation of the detector diode characteristics due to laser-induced heating. The time and wavelength dependence agree with the predictions of a thermal model which treats a semi-infinite material irradiated by a Gaussian laser beam. The energy density thresholds are independent of for short irradiation times and asymptotically approach a limiting behaviour which increases as for long times. They are given by the empirical relationE ₀=65[1+217/tan^–1(258)^1/2] J cm^–2 for 1.06m radiation. The thresholds at short irradiation times of detectors damaged by 1.06m radiation are about 25 times larger than those of detectors exposed to 0.6943m radiation. The greater susceptibility at 0.6943m is attributed to a larger optical absorption coefficient.     

The hydrodynamic limit of a one-dimensional nearest neighbor gradient system

We study the hydrodynamic behavior of a one-dimensional nearest neighbor gradient system with respect to a positive convex potential . In the hydrodynamic limit the density distribution is shown to evolve according to the nonlinear diffusion equation ,(q)/t= (²/dq²){F([1/₁(q)]), with F= –.     

Radiation effects in the production and decay of ψ mesons by leptons

A new expression _e is obtained for resonance in the reaction e⁺e^– ar ^+– with allowance for the radiative corrections, which also contain the emission of hard photons by the final leptons and the final value of the energy resolution E. An expression is obtained for the total probability of radiative lepton decay. A numerical analysis of the experimental data is made for the reaction ^+–, and the parameters e⁺e^– (3, 1) e⁺e^–, and _e ² /, _e, and are determined for (3, 1) resonance-with allowance for the radiative corrections.This paper was read (November 17–21, 1975) at a session on high-energy physics of the Department of Nuclear Physics of the Academy of Sciences of the USSR.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 29–34, March, 1977.     

Sensitivity of approximate formulas for determining optical constants of thin films

The sensitivity of approximate formulas for determining the optical constants of thin films using measurement of reflectancesR and transmittancesT at normal incidence have been investigated theoretically. The ranges of refractive indexn, absorption indexk,2nk (=₂) andn ²–k ²(=₁) within relative errors of 5%, 10%, and 20% may be obtained. Selected signs of (₁)⁺ or (₁)^– have been determined. Validity of the condition n₀ A=n _s A has been also evaluated (A=1–R –T andA=1–R–T).     

Internal friction of alkali-halide crystals with small strains

A study is made of the strain-amplitude dependence of internal friction (IF) and the Young's modulus defect in alkali-halide crystals at amplitudes ₀ 10^–7-10^–6. It is found that If is amplitude-independent at room temperature but becomes dependent on strain amplitude and time when measured in an electric field and at elevated temperatures. In these cases, an asymmetric hysteretic peak is seen on the curve (₀). The peak is due to the thermally activated release of dislocations from weak pinning points as the dislocations vibrate inside ionic atmospheres. The energies of the ruptured bonds (0.03–0.11 eV) are typical of cationic vacancies.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 44–50, January, 1995.     

Beta-decay asymmetries in polarized12B and12N and theG-parity non-conservation

The decay asymmetries (A) in polarized¹²B and¹²N have been measured as a function of -ray energies (E). The coefficients _± inA = ±P(p/E) (1+_± E) have been determined to be _–(¹²B) =+(0.31±0.06)%/MeV and ₊(¹²N) = –(0.21±0.07)%/MeV. The experimental value, _––₊=(0.52±0.09)%/MeV, is larger than the prediction according to conservation of vector current which includes no second-class current, _––_{+ CVC}0.27%/MeV, and indicates the existence of the second-class induced-tensor current.This work has been done in collaboration with I. Tanihata and J. Göring.     

Perturbations of flows on Banach spaces and operator algebras

For automorphism groups of operator algebras we show how properties of the difference _t – ' _t are reflected in relations between the generators , . Indeed for a von Neumann algebraM with separable predual we show that if _t – '_t 0.28 for smallt, then = 0(+)°^-1 where is an inner automorphism ofM and is a bounded derivation ofM. If the difference _t – ' _t =O(t) ast ; 0, then = + and if _t – ' _t 0.28 for allt then =. We prove analogous results for unitary groups on a Hilbert space andC ₀,C ₀ ^* groups on a Banach space.This paper subsumes an earlier work of the same title which appeared as a report from Z.I.F. der Universität BielefeldWith partial support of the U.S. National Science Foundation     

Nelson's symmetry and the infinite volume behavior of the vacuum inP(φ)2

LetH _l be the Hamiltonian in aP()₂ theory with sharp space cutoff in the interval (–l/2,l/2). LetE _l =inf(H _l ), (l)=–E _l /l, and let _l be the vacuum forH _l . discuss properties of (l) and _l . In particular, asl, there are finite constants <0 and such that (l), ((l)–)l, and hence (l)=+/l+o(l ^–1). Moreover exp(–c ₁ l) _{l 1}exp(–c ₂ l) forc ₁,c ₂ positive constants, where _{l 1} is theL ¹(Q, d₀) norm of ₁ with respect to the Fock vacuum measure. We also present a new proof of recent estimates of Glimm and Jaffe on local perturbations ofH _l in the infinite volume limit.Research sponsored by AFOSR under Contract No. F44620-71-C-0108.On leave from Istituto di Fisica Teorica, Universitá di Napoli and Istituto Nazionale di Fisica Nucleare, Sezione di Napoli.A. Sloan Foundation Fellow.     

Maximum mass-particle velocities in Kantor's information mechanics

Kantor's information mechanics links phenomena previously regarded as not treatable by a single theory. It is used here to calculate the maximum velocities _m of single particles. For the electron, _m/c1–1.253814×10^–77. The maximum _m corresponds to _m/c1–1.097864×10^–122 for a single mass particle with a rest mass of 3.078496×10^–5g. This is the fastest that matter can move. Either information mechanics or classical mechanics can be used to show that _m is less for heavier particles. That _m is less for lighter particles can be deduced from an information mechanics argument alone.     

Some exact solutions to the sine-Gordon equations

We present some new exact (solitary and traveling) solutions to the sine-Gordon equationsc ²u_xx–u_tt = sinu andcu _xt+ u_tt = sinu, and the dissipative sine-Gordon equationc ²u_xx–u_tt–u_t=₁ sinu+ ₂ sin(2u). Here,, ₁, and ₂ are the coupling constants, real numbers;c is theintrinsic speed of the propagating wave determined by the system; and is the damping factor. The physical implication is briefly discussed.     

Slowing down of retrieval in the hopfield model

The variation of the convergence time, as a function of the storage capacity is studied numerically for systems ranging in size fromN=1000 toN=16,000 neurons. is found to increase likeexp[–A(_c–)] as one nears the critical storage capacity _c =0.142=0.002.     

Special frequencies and Lifshitz singularities in binary random harmonic chains

We consider a one-dimensional chain of coupled harmonic oscillators; the mass of each atom is a random variable taking only two values (M or 1). We investigate the integrated density of statesH(²) near special frequencies: a given frequency _s with rational wavelength becomes special if the mass ratioM exceeds a certain critical valueM _c . We show thatH has essential singularities of the typesH _sg exp(–C ₁ ¦²– _s ² ¦^–1/2) or exp(–C ₂¦²– _s ² ¦^–1), according to the value ofM and the sign of (²– _s ² ). The Lifshitz singularity at the band edge is analyzed in the same way. In each case, the constantC ₁ orC ₂ is evaluated explicitly and compared with a vast amount of numerical work. All these exponential singularities are modulated by periodic amplitudes. The properties of the eigenfunctions with frequencies close to the special values are also discussed, and are illustrated by numerical data.     

Existence of three phases for aP(ϕ)2 model of quantum field

In the two-dimensional model of the quantum field theory with lagrangean density :()²–(–)^{21/2 4}–⁶: there exist (at least) three different phases for small and some ().