Exact correlated kinetic energy related to the electron density for two-electron model atoms with harmonic confinement

For arbitrary interparticle interaction u(r₁₂), the model two-electron atom in the title is shown to be such that the ground-state electron density ρ(r) is determined uniquely by the correlated kinetic energy density t_R(r) of the relative motion. Explicit results for t_R(r) are presented for the Hookean atom with force constant k=1/4, and also for . Possible relevance of the Hookean atom treatment to the ground state of the helium atom itself is briefly discussed.     

Materials with a desired refraction coefficient can be made by embedding small particles

A method is proposed to create materials with a desired refraction coefficient, possibly negative one. The method consists of embedding into a given material small particles. Given n₀(x), the refraction coefficient of the original material in a bounded domain , and a desired refraction coefficient n(x), one calculates the number N(x) of small particles, to be embedded in D around a point xD per unit volume of D, in order that the resulting new material has refraction coefficient n(x).     

Dynamics and statistics study of rings formed by magnetic balls

The statistical distribution and stability of the ring structure formed by magnetic balls without a magnetic field are studied experimentally and theoretically. Experimental results show that the ring structure of the magnetic balls that are contacted one by one can easily appear. We tested 500 samples to count the probability, P(N), of the appearance of the rings and found that the number of balls, N, in a ring is limited only in the region from 4 to 20. The dependence of the probability, P(N), on the number of balls, N, follows a Poisson-like distribution. The origin of this Poisson distribution is disclosed by the statistics. Based on the classical “spin dynamics + molecular dynamics”, the stability of the ring structure was also investigated. The peak of function P(N) vs. N at 9 and the non-existence of rings with N=3 and N>20 is shown. An internal scaling relation between P(N) and the critical field h_c(N) for breaking the ring is found.     

The finite-size scaling study of the specific heat and the Binder parameter for the six-dimensional Ising model

The six-dimensional Ising model with nearest-neighbor pair interactions is simulated on the Creutz cellular automaton by using the finite-size lattices with the linear dimensions L=4,6,8,10. The temperature variations and the finite-size scaling plots of the specific heat and Binder parameter verify the theoretically predicted expression near the infinite lattice critical temperature. The approximate values for the critical temperature of the infinite lattice T_C=10.838(1), T_C=10.836(20) and T_C=10.835(1) are obtained from the intersection points of specific heat curves, Binder parameter curves and the straight line fit of specific heat maxima, respectively. These results are in agreement with the more precise value of T_C=10.835(5). The value obtained for the critical exponent of the specific heat, i.e., =0.012(2) is also in agreement with =0 predicted by the theory.     

Exact Hamiltonian for an analytic correlated ground-state wave function for He-like ions

A correlated three-parameter variational ground-state Ψ(r₁,r₂,r₁₂) proposed by Chandrasekhar for helium-like ions gives a high percentage of the electron correlation energy resulting from the interaction energy e²/r₁₂ and also yields an analytic ground-state electron density ρ(r). Here, we extract via Schrödinger equation an exact Hamiltonian for which the Chandrasekhar wave function is the ground-state. Properties of the potential energy function in this Hamiltonian are quantified. Finally, kinetic energy densities are plotted and related to the Laplacian of ρ(r).     

: Hadronic molecules in effective field theory

We consider the implications from the possibility that the recently observed state X(3872) is a meson–antimeson molecule. We write an effective Lagrangian consistent with the heavy-quark and chiral symmetries needed to describe X(3872). We explore the consequences of the assumption that X(3872) is a molecular bound state of D^*0 and mesons for the existence of bound states in the and channels.     

Peakon, compacton and loop excitations with periodic behavior in KdV type models related to Schrödinger system

In this Letter, the linear variable separation approach is successfully extended to (1+1)-dimensional Korteweg–de Vries (KdV) type models related to Schrödinger system. Some significant types of solitons such as compacton, peakon and loop solutions with periodic behavior are simultaneously derived from the (1+1)-dimensional soliton system by entrancing appropriate piecewise smooth functions and multivalued functions.     

Discrete symmetry and CP phase of the quark mixing matrix

A simple specific pattern of the two 3×3 quark mass matrices is proposed, resulting in a prediction of the CP phase of the charged-current mixing matrix V_CKM, i.e., sin2₁(β)=0.733, which is in remarkable agreement with data, i.e., sin2₁=0.728±0.056±0.023 from Belle and sin2β=0.722±0.040±0.023 from BaBar. This pattern can be maintained by a discrete family symmetry, an example of which is D₇, the symmetry group of the heptagon.     

The new multiplet, heavy baryon mass predictions, meson–baryon universality and effective supersymmetry in hadron spectrum

The recent measurement by CDF M(Σ_b)−M(Λ_b)=192 MeV is in striking agreement with our theoretical prediction M(Σ_b)−M(Λ_b)=194 MeV. In addition, the measured splitting agrees well with the predicted splitting of 22 MeV. We point out the connection between these predictions and an effective supersymmetry between mesons and baryons related by replacing a light antiquark by a light diquark. We discuss the theoretical framework behind these predictions and use it to provide additional predictions for the masses of spin- and spin- baryons containing heavy quarks, as well as for magnetic moments of Λ_b and Λ_c.     

Lower hybrid current drive experiments with graphite limiters in the HT-7 superconducting tokamak

Recent progress of lower hybrid (LH) experiments with new graphite limiters configuration in the HT-7 tokamak is presented. The lower hybrid current drive (LHCD) efficiency can be determined by fitting based on experimental data. Improved particle confinement was observed via LHCD (P_LHW>300 kW) characterized by the particle confinement time τ_p increased about 1.56 times. It is found that runaways are suppressed during loop voltage is decreasing at the flat-top phase of LH discharges. The main limitations of pulse length are presented in long-pulse experiments with new limiter configuration.     

Charmed-meson fragmentation functions with finite-mass corrections

We elaborate the inclusive production of single heavy-flavored hadrons in e⁺e⁻ annihilation at next-to-leading order in the general-mass variable-flavor-number scheme. In this framework, we determine non-perturbative fragmentation functions for D⁰, D⁺, and D^*+ mesons by fitting experimental data from the Belle, CLEO, ALEPH, and OPAL Collaborations, taking dominant electroweak corrections due to photonic initial-state radiation into account. We assess the significance of finite-mass effects through comparisons with a similar analysis in the zero-mass variable-flavor-number scheme. Under Belle and CLEO experimental conditions, charmed-hadron mass effects on the phase space turn out to be appreciable, while charm-quark mass effects on the partonic matrix elements are less important.     

Intense red mechanoluminescence from (ZnS)1−x(MnTe)x

Intense mechanoluminescent (ZnS)_1−x(MnTe)_x powder samples with x=0.02,0.05,0.10,0.15,0.20 and 0.25 were prepared by simple Solid State Reaction method. All samples were polycrystalline with wurtzite structure. Mechanoluminescence (ML) and Photoluminescence (PL) were observed in all the samples in the red region peaking around 650 nm. The red emission is attributed to the presence of Te along with Mn. ML is attributed to the release of holes due to the stress on the phosphors which then recombine with metastable Mn²⁺ emitting light. The intensity of ML is found to be strongly dependent on both the impact pressure and composition. The maximum intensities in both ML and PL were observed in samples with x=0.05.     

Study of the decay

Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement for the Cabibbo-suppressed decay mode D⁰→K⁺K⁻π⁺π⁻. We measure: Γ(D⁰→K⁺K⁻π⁺π⁻)/Γ(D⁰→K⁻π⁻π⁺π⁺)=0.0295±0.0011±0.0008. An amplitude analysis has been performed in order to determine the resonant substructure of this decay mode. The dominant components are the decays D⁰→K₁(1270)⁺K⁻, D⁰→K₁(1400)⁺K⁻ and D⁰→ρ(770)⁰(1020).     

Corner bifurcations in non-smoothly forced impact oscillators

We consider an impacting mechanical system in which a particle at position u(t) impacts with a periodically moving obstacle at position z(t), the motion of which is non-smooth. In particular we look at corner events when u impacts with z very close to a point where z loses smoothness. We show that this leads, through a corner bifurcation, to complex dynamics in u which can include periodic orbits of arbitrary period and period-adding cascades. By analysing associated maps close to the corner event, we show that this dynamics can be understood in terms of the iterations of a two-dimensional, piecewise linear, discontinuous map. We also show some links between this analysis and the difficult problem of understanding the motion of three objects which may have simultaneous impacts.     

Search for intermediate mass magnetic monopoles and nuclearites with the SLIM experiment

SLIM is a large area experiment (440 m²) installed at the Chacaltaya cosmic ray laboratory since 2001, and about 100 m² at Koksil, Himalaya, since 2003. It is devoted to the search for intermediate mass magnetic monopoles (10⁷–10¹³ GeV/c²) and nuclearites in the cosmic radiation using stacks of CR-39 and Makrofol nuclear track detectors. In four years of operation it will reach a sensitivity to a flux of about 10^-15 cm^-2 s^-1 sr^-1. We present the results of the calibration of CR-39 and Makrofol and the analysis of a first sample of the exposed detector.     

Enhanced quantum searching via entanglement and partial diffusion

In this paper, we will define a quantum operator that performs the standard inversion about the mean only on a subspace of the system (Partial Diffusion Operator). This operator is used together with entanglement in a quantum search algorithm that runs in for searching an unstructured list of size N with M matches such that 1≤M≤N. We will show that the performance of the algorithm is more reliable than known fixed operators quantum search algorithms especially for multiple matches where we can get a solution after a single iteration with probability over 90% if the number of matches is approximately more than one-third of the search space. We will show that the algorithm will be able to handle the case where the number of matches M is unknown in advance in such that 1≤M≤N.     

Chiral dynamics and antikaon-nuclear quasibound states

Recent developments are summarised concerning low-energy interactions as they relate to the possible existence of antikaon-nuclear quasibound states. An exploratory study of antikaons bound to finite nuclei is performed, with emphasis on the evolution of such states from light to heavy nuclei (A = 16–208). The energy dependent, driving attractive interactions are constructed using the s-wave coupled-channel amplitudes involving the Λ(1405) and resulting from chiral SU(3) dynamics, plus p-wave amplitudes dominated by the Σ(1385). Effects of Pauli and short-range correlations are discussed. The decay width induced by K⁻NN two-body absorption is estimated and found to be substantial. It is concluded that -nuclear quasibound states can possibly exist with binding energies ranging from 60 to 100 MeV, but with short life times corresponding to decay widths of similar magnitudes.     

Modelling interstellar extinction and polarization with spheroidal grains

We calculate the wavelength dependence of the ratio of the linear polarization degree to extinction (polarizing efficiency) P(λ)/A(λ) from the ultraviolet to near-infrared. The prolate and oblate particles with aspect ratios from a/b=1.1 up to 10 are assumed to be rotating and partially aligned with the mechanism of paramagnetic relaxation (Davis–Greenstein). Size/shape/orientation effects are analyzed. It is found that the wavelength dependence of P(λ)/A(λ) is mainly determined by the particle composition and size whereas the values of P(λ)/A(λ) depend on the particle shape, degree and direction of alignment.     

Is the β phase maximal?

The current experimental determination of the absolute values of the CKM elements indicates that 2|V_ub/V_cbV_us|=(1−z), with z given by z=0.19±0.14. This fact implies that irrespective of the form of the quark Yukawa matrices, the measured value of the SM CP phase β is approximately the maximum allowed by the measured absolute values of the CKM elements. This is for , which implies =π/2. Alternatively, assuming that β is exactly maximal and using the experimental measurement sin(2β)=0.726±0.037, the phase γ is predicted to be γ=(π/2−β)=66.3°±1.7°. The maximality of β, if confirmed by near-future experiments, may give us some clues as to the origin of CP violation.     

Near tribimaximal neutrino mixing with symmetry

The discrete subgroup Δ(27) of SU(3) has the interesting multiplication rule , which is used to obtain near tribimaximal neutrino mixing. Using present neutrino oscillation data as input, this model predicts that the effective mass m_ee measured in neutrinoless double beta decay will be 0.14 eV.