Origin of 1ƒ noise

$\text{1}\text{?}$ noise dependence on temperature for both n- and p-type silicon has been measured. The formula for calculation of $\text{1}\text{?}$ noise is presented. The formula has been derived by presumption that only lattice scattering gives $\text{1}\text{?}$ noise. A good agreement between calculations and experimental results is found.     

Surface core level spectroscopy of the stepped surface W [6(110)×(110)]

The binding energies of 4f surface core levels on a stepped $\text{W}\text{[6(110)×(1}\text{1}\text{0)]}$ are studied both theoretically and experimentally. The core level emission of the outer edge of the steps is clearly seen on the experimental spectra in addition to bulk and terrace emissions. A more refined decomposition puts forward the existence of two new peaks which are assigned to the emission of the inner edge and its neighboring terrace row by comparison with theoretical results.     

NMR relaxation at low temperature in one dimensional antiferromagnets: Comparison between S = 12 and S = 52

The proton spin-lattice relaxation time T₁ has been measured at low temperatures in spin $\text{5}\text{2}$ (CH₃)₄NMnCl₃ (TMMC) and spin $\text{1}\text{2}$ CuCl₂2NC₅H₅ (CuPC). The two systems have very different temperature dependences which we attribute to the different spin values.     

Phonon observations from 1ƒ noise measurements

From mobility fluctuation $\text{1}\text{?}$ noise parameter measurements five phononic energies corresponding to LO, TO vibrational modes as well as TA + S₂ or O, TO + TA, TO + O combined modes were identified. They stand for phonon replicas of non-radiative recombination processes. It is thus demonstrated that the carrier-phonon interaction is the source of $\text{1}\text{?}$ noise in semiconductors.     

Comparison of pp and pp interactions at s = 53 GeV

Results are presented from the first p$\text{p}$ colliding beam runs at the CERN ISR, using the UA5 streamer chamber detector. p$\text{p}$ interactions at $\text{s}\text{= 53}\text{GeV}$ are compared with pp data taken in the same experiment. The results are in good agreement with extrapolations of low-energy p$\text{p}$ data.     

Electronic structure of the GeGaAs (111) and (111) heterojunctions

The electronic density of states for GeGaAs (111) and ($\text{1}$$\text{1}$$\text{1}$) heterojunctions has been calculated. No interface states in the fundamental gap are found. A sizeable density of interface states below the top of the valence band is found for GeGa bonds-(111) junctions-interface states in the ionic gap are reported. The effect of varying the amount of the valence band discontinuity across the interface is discussed.     

Scattering of solitons with fermion number ±12

In a model of a Dirac field coupled to a sine-Gordon system, we have soliton solutions with half-integral fermion number. Scattering problems of such solitons are investigated. For soliton-soliton and soliton-antisoliton solutions, we find explicit solutions to the Dirac equations which are localized at the position of the (anti-)solitons. It is shown that the fermion number is generally transferred between the soliton and the (anti-)soliton in the scattering process.     

Structures in pp → ππ

A Barrelet-zero analysis is presented of data on $\text{p}\text{p}\text{→ π π}$ in the momentum range 1 to 2 GeV/c. With π^?π⁺ data alone, the slope for ambiguity is very large, but the addition of π⁰π⁰ information enables the number of solutions to be reduced to just a few. Although the alternative solutions differ considerably, they significant common features, in particular, with plausible extra assumptions, all solutions appear to be dominated by resonances in all spin states from J = 1 to 5.     

The spin 12 gravitational anomalous magnetic moment

The gravitational anomalous magnetic moment of a spin $\text{1}\text{2}$ particle is calculated and compared with an earlier dimensional regularization result. The answers disagree although both agree the answer is finite. It is argued that this quantity is not uniquely determined by physical requirements. The methods used are shown to respect the gravitational and electromagnetic gauge invariances. In addition, a physical interpretation of the regularization method employed is offered.     

Relativistic transport equation for spin 12 particles

For the model of positive energy Dirac particles with short range interaction a transport equation for the one- particle Wigner function is obtained. This transport equation is a generalization of the non-relativistic Walsmann- Snider equation for spin particles.     

Spin-12 particles in the field of monopoles

The equations of motion of a $\text{spin}\text{-}\text{1}\text{2}$ particle in the field of a point-like (Abelian and non-Abelian) monopole are solved; helicity states and scattering solutions are constructed. The motion in an extended monopole and dyon source is discussed: charge-exchange scattering amplitudes are computed in the distorted-wave Born approximation. By the introduction of suitable spinors, the separation of variables is accomplished for any value of isospin. The non-existence of fermion zero modes in the field of an SU(2) monopole when $\text{T > 1, J >}\text{1}\text{2}$ is shown.     

Quark-tadpole origin of the ΔI = 12 rule

In the context of a two-quark field picture of current quarks and renormalized constituent quarks, we show that an s-d current-quark tadpole generated by the weak Cabbibo-GIM current appears in the current-quark nonleptonic ΔY = 1 hamiltonian. Then we demonstrate that this $\text{ΔI =}\text{1}\text{2}$ operator in fact sets the observed scale of the K_s→ππ decays without recourse to any fitted parameters.     

Electrical conduction and 1ƒ noise in Li-DOPED MnO

Electrical resistivity, thermoelectric power and current noise were measured on Li-doped MnO single crystals in the temperature range from 300 to 1000 K. Below 700 K the crystals are p-type and the activation energy of the resistivity is 0.75 eV. Around 700 K the activation energy changes from 0.75 to 1.25 eV owing to a change from p- to n-type conduction. The depth of the Li acceptor is found to be 0.65 eV. From resistivity and thermoelectric power data it is concluded that the bandgap in first approximation can be written as E_s(T) = E_o ? γT between 750 and 1000 K, with E_o = 1.9 eV and γ = 6 × 10^?4 eV/K. The current noise spectra show $\text{1}\text{?}$ noise. The magnitude of the $\text{1}\text{?}$ noise is strongly temperature dependent. From the noise data it is deduced that E_o = 2.2 eV and γ = 10^?3 eV/K in the temperature range 430–700 K.     

D-state effects in (d, t) and (d, 3He) reactions

The influence of the deuteron and triton [³He] D-state on the form factor required in the DWBA analyses of the ($\text{d}$, t) [($\text{d}$, ³He)] reactions has been studied. The wave functions of Phillips are used for three-nucleon systems because they are designed to yield the correct asymptotic form for the (d, t) and (d, ³He) overlaps. The zero-range parameters D₀ and D₂ which enter into the calculation of the cross section and the tensor analysing power in the DWBA with the local energy approximation are calculated and found to yield values consistent with experimental data.     

Optimal sum-rule inequalities for spin-12 compton scattering

A formalism appropriate for model-independent dispersion theoretical investigations of the (not necessarily forward) Compton scattering off $\text{spin}\text{-}\text{1}\text{2}$ hadronic targets, which fully exploits the analyticity properties of the amplitudes (to lowest order in electromagnetism) in ν² at fixed t ($\text{ν =}\text{1}\text{4}\text{(s ? u); s, t}$, u = Mandelstam variables), is developed. It relies on methods which are specific to boundary-value problems for analytic matrix-valued functions. An analytic factorization of the positive definite hermitian matrix associated with the bilinear expression of the unpolarized differential cross section (u.d.c.s.) in terms of the Bardeen-Tung (B.T.) invariant amplitudes is explicitly obtained. For t in a specified portion of the physical region, six new amplitudes describing the process are thereby constructed which have the same good analyticity structure in ν² as the (crossing symmetrized) B.T. amplitudes, while their connection with the usual helicity amplitudes is given by a matrix which is unitary on the unitarity cut. A bound on a certain integral over the u.d.c.s. above the first inelastic threshold, established in terms of the target's charge and anomalous magnetic moment, improves a previous weaker result, being now optimal under the information accepted as known.     

Q gravity

The geometrical structure of an extended theory of gravitation incorporating the quaternion field is investigated. A lagrangian is constructed and shown to be pure real as a consequence of the geometrical structure. The structure of spacetime becomes nonabelian; however, the base manifold in which physics takes place, remains real and n-dimensional.     

The U(612) supersymmetric limit of the interacting Boson-Fermion Model

The $\text{U(}\text{6}\text{12}\text{)}$ dynamical supersymmetry of the Interacting Boson-Fermion Model, appropriate for nuclei where the odd nucleon can occupy the single-particle orbits $\text{J =}\text{1}\text{2}\text{,}\text{3}\text{2}\text{,}\text{and}\text{5}\text{2}$ is analyzed. The subgroup structure of $\text{U(}\text{6}\text{12}\text{)}$ is discussed and the generators and Casimir operators of these subgroups are given. In each of the three dynamical symmetries of $\text{U(}\text{6}\text{12}\text{)}$ the energy formulas, reduction rules, and wave functions are obtained and closed expressions for E2 transition rates and one-nucleon transfer intensities are derived. Examples of $\text{U(}\text{6}\text{12}\text{)}$ symmetries are presented.     

The quark sea and the ΔI = 12 rule

The effect on nonleptonic processes of quark-antiquark pairs due to quantum chromodynamics is studied. Their presence improves agreement between theory and experiment for hyperon decays. In kaon decays a new $\text{ΔI =}\text{1}\text{2}$ contribution is found, but $\text{Δ =}\text{3}\text{2}$ effects are still large to to be in agreement.     

Integral representation for the spin 12 Ising ferromagnet

A simpler derivation is given for a recently discovered integral representation for the spin $\text{1}\text{2}$ Ising ferromagnet.     

Possible origin of S =12 ESR lines in alkali-TCNQ Salts

Solitons in spin Peierls systems are studied with emphasis on the contribution of solitions to the ESR spectra. It is pointed out that the ESR line ($\text{S =}\text{1}\text{2}$) observed in simple alkali-TCNQ salts can be due to solitons in spin Peierls state.