D and Ds in mass loaded flux tube

Heavy-light hadrons are studied in a mass loaded flux tube model. The study indicates that the dynamics of mesons and baryons containing a c quark is described well by the mass loaded flux tube. The hypothesis of good diquark-antiquark degeneracy is found reasonable in heavy-light quark systems. The spectrum of charmed （D） and charmed strange （Ds） mesons is systematically computed. D and Ds in 1D multiplets are predicted to have lower masses in comparison with other theoretical predictions. The predicted masses of the 1（13D1） and the 3（13D3） Ds agree well with those of recently observed Ds1（2700）± and DsJ（2860）, respectively.     

Confinement and the global SU(3) color symmetry

The global SU(3)color symmetry and its physical consequences are discussed.The Nother current is actually governed by the conserved matter current of color charges if the color field generated by this charge is properly polarized.The color field strength of a charge can have a uniform part due to the nontrivial QCD vacuum field and the nonzero gluon condensate,which implies that the self-energy of a system with a net color charge is infinite and,therefore,cannot exist as a free state.This is precisely what color confinement means.Accordingly,the Cornell type potential with the feature of Casimir scaling is derived for a color singlet system composed of a static color charge and an anti-charge.The uniform color field also implies that a hadron has a minimal size and minimal energy.Furthermore,the global S U(3)color symmetry requires that the minimal irreducible color singlet systems can only be qq,qqq,gg,ggg,qqg,qqqg,qqqg,etc.,therefore a multi-quark system can only exist as a molecular configuration if there are no other binding mechanisms.     

D and D_s in mass loaded flux tube

Heavy-light hadrons are studied in a mass loaded flux tube model. The study indicates that the dynamics of mesons and baryons containing a c quark is described well by the mass loaded flux tube. The hypothesis of good diquark-antiquark degeneracy is found reasonable in heavy-light quark systems. The spectrum of charmed (D) and charmed strange (Ds) mesons is systematically computed. D and Ds in 1D multiplets are predicted to have lower masses in comparison with other theoretical predictions. The predicted masses of the 1(13D1) and the 3(13D3) Ds agree well with those of recently observed Ds1(2700)± and DsJ(2860), respectively.     

A model for LED spectra at different drive currents

A mathematical model for the spectra of monocolor light-emitting diodes （LEDs） and phosphor-coated white LEDs at different drive currents is established.The simulation program of the color rendering of a white light LED cluster is developed based on this model.The program can predict not only the spectral power distribution and color rendering index （CRI）,but also the number of LEDs,drive currents,input power,and luminous efficacy of a white light LED cluster at a given color temperature according to the requirement of the luminous flux.The experimental results show that the relative spectral power distributions （SPDs） and chromaticity coordinates of the model LED are very close to that of the real LED at different drive currents.Moreover,the correlated color temperature （CCT）,CRI,special color rendering index （R9） luminous flux,input power,and luminous efficacy of the white light LED cluster predicted by simulation are also very close to the measured values.Furthermore,a white/red cluster with high rendering （CCT=2903 K,CRI=91.3,R9=85） and a color temperature tunable warm-white/red/green/blule LED cluster with high rendering （CCT=2700 6500 K,CRI 〉 90,R9 〉 96） are created.     

A Quasi—One—Dimensional Model for a Solar Flux Tube

We develop the quasi-one-dimensional flux tube model with magnetohydrodynamical equations.In order to know whether the magnetic field can maintain their similar structure from photosphere to chromosphere,we suppose that the flux tube is thin in radius relative to the length,and that the quantities in the cross section are averaged.The radii of the flux tube and the magnetic field are numerically simulated.One of the important results shows that the flux tube does not expand as quickly as the existing model when it is out of the photoxphere with high velocity.This is consistent with observations of the magnetic field in the photosphere and chromosphere.     

Measurements of cirrus clouds with a three-wavelength lidar

A three-wavelength lidar system is set up. The backscatter signals of 355, 532, and 1 064 nm are mea- sured simultaneously to derive the optical depth, lidar ratio, and backscatter color ratio of cirrus clouds, respectively. The lidar configuration and the data processing are described. The case study shows that the optical depths of cirrus clouds are not dependent on wavelength while the backscatter color ratios are.     

AC Alternating-Current Loss Analyses of a Thin High-Temperature Superconducting Tube Carrying AC Transport Current in AC External Magnetic Field

Numerical simulations on the AC loss characteristics in a thin high-temperature superconducting （HTS） tube are presented. Geometry of the HTS conductor is modeled as a tube with negligible thickness, and assumed to carry a transport current with the same phase as an AC externally applied magnetic field perpendicular to the axis. Based on the classical theory of AC loss with the Bean critical current model, the distribution of critical current density jc and AC loss Q are obtained by means of numerical analysis. The results are in very good agreement with experiments. A double-peak profile is observed in the curve of the critical current density distribution along the azimuth angle. This numerical simulation method is suitable for a thin HTS tube, which may be applicable on a thin tube configuration consisting of coated superconductors.     

Thermal analysis of GaN laser diodes in a package structure

Using the finite-element method,the thermal resistances of GaN laser diode devices in a TO 56 package for both epi-up configuration and epi-down configuration are calculated.The effects of various parameters on the thermal characteristics are analysed,and the thicknesses of the AlN submount for both epi-up configuration and epi-down configuration are optimized.The obtained result provides a reference for the parameter selection of the package materials.     

Properties of deformed Λ hypernuclei

The properties of Be and B isotopes and the corresponding Λ hypernuclei are studied by using a deformed Skyrme Hartree-Fock approach with realistic nucleonic Skyrme forces, pairing correlations, and a microscopically determined lambda-nucleon interaction based on Brueckner-Hartree-Fock calculations of hypernuclear matter. The results suggest that the core nuclei and the corresponding hypernuclei have similar deformations with the same sign.     

Color reproduction from desktop display to projector based on visual matching

We present a novel method of color reproduction from desktop displays to projectors via visual assessment. The model is based on visual matching nine color patches between a display and a projector. The effects of the method to improve color reproduction are tested for 30 samples by visual and color difference evaluations. The expeirmental results of visual evaluation show that the color reproduction is improved by 87.5%. The maximum, minimum, and average color differences between the displayed colors and the projected ones before and after correction are 28.94, 4.35, 16.78, 16.51, 0.64, and 3.51 △Eab^＊ units respectively, which are consistent with the results of visual evaluation.     

Magnetic Symmetry,Regge Trajectories,and the Linear Confinement in Dual QCD

Using the magnetic symmetry structure of non-Abelian gauge theories, we analyze the flux tube formulation and its implications on the hadronic Regge trajectories and the confinement of color isocharges in magnetically condensed (with as well as without the electric excitations) QCD vacuum. Starting with the fiber bundle structure of QCD, the dual potentials are used to construct the QCD Lagrangian which has been shown to develop a unique flux tube configuration in its dynamically broken phase. The vector mass mode of the condensed vacuum has been shown to play a leading role in flux tube energy and other confinement parameters. Using the flux tube energy and the angular momentum, the Regge trajectories for hadrons have been obtained and the linear confining properties of dual QCD have been established. The dyonic flux tube structure of the condensed QCD vacuum has been obtained by inducing the electric excitation of QCD monopoles and the confining nature along with the linearity of Regge trajectories in dyonically condensed QCD vacuum are shown to remain intact. Implications of the modification in Regge slope parameter, on improving the confining properties of dual QCD vacuum are also discussed. PACS: 12.38.Aw; 11.30.-j; 14.80.Hv; 12.39.Mk An erratum to this article is available at .     

Dynamical Calculation of Θ+ Mass and Decay width in the Quark Model

In this paper we study the mass splitting and the decay width of pentaquark (Θ⁺) at the ground states in the framework of flux tube, quark delocalization and color screening model. We consider the pentaquark as diquark-triquark configuration and obtained closer values of mass splitting and the decay width of Θ⁺ to the experimental data.     

A zero-mode quantization of the skyrmion

In the semi-classical approach to the Skyrme model, nuclei are approximated by quantum mechanical states on a finite-dimensional space of field configurations; in zero-mode quantization this space is generated by rotations and isorotations. Here, simulated annealing is used to find the axially symmetric Skyrme configuration which extremizes the zero-mode quantized energy for the nucleon.     

Hybrid mesons in the context of the relativistic equation

The flux tube model of hybrid mesons is studied in the context of the relativistic equation in the adiabatic approximation. The moment of inertia of the rigid-rod flux tube is considered in the kinetic part of the interaction. The nonrelativistic and relativistic one scalar bead flux tube is integrated numerically and compared with the adiabatic flux tube small oscillation approximation. The relativistic scalar bead picture suggests that the lowest gluonic excitation of a massive gluon is color octet q q? pair while the conventional mesons are color singlet as usual. We estimate the lowest hybrid charmonium states as 1₁ P = 4.17 ± 0.03 and 1₁D = 4.39±0.05 GeV with color octet qq pair and as 1₁P = 3.78± 0.05 and 1₁D = 4.04±0.09 GeV with color singlet q q? pair. These results are also confirmed by the adiabatic flux tube small oscillation approximation when the hybrid energy gap is adjusted phenomenologically to M _Hc = M _ground + 1GeV.     

Colored Flux Tube in Euclidean Spacetime

No Heading The flux tube solution in the Euclidean spacetime with the color longitudinal electric field in the SU(2) Yang-Mills-Higgs theory with broken gauge symmetry is found. Some arguments are given that this flux tube is a pure quantum object in the SU(3) quantum theory reduced to the SU(2) Yang-Mills-Higgs theory.     

Roper Resonances as Vibrating Flux Tubes Between Quarks

The Roper resonances of the nucleon are described as transverse vibrations of astretched flux tube between the three quarks. The proton is modeled using currentmass quarks interacting with a confining linear flux tube potential plus thespin-dependent parts of a one-gluon exchange potential. The proton ground state hasno vibrations and the confining flux tube has the minimum length required toconnect the three quarks. The flux tube has a V or Y shape of two or threesegments, depending on the locations of the quarks. The vibrations of the fluxtube have nodes at the quarks and at the apex of the Y-shaped configuration andprovide the vibrational excitation energy to describe the proton excitations. Theamplitude of the transverse vibrations is found from a geometric analysis, anddepends on the string constant of the flux tube potential. The Roper 1. 440-GeVresonance energy is very nearly reproduced by the vibration with mode number1 acting in only one segment of the flux tube. The vibration with mode number2 in one segment of the flux tube closely reproduces the second proton excitationat 1.710 GeV. The D excited states are also well reproduced by these modes ofa vibrating flux tube.     

Spectroscopy of light nuclei with skyrme-type interactions

Deformed Hartree-Fock calculations are performed for some light nuclei in a large configuration space consisting of first four major shells. The interaction employed is the modified Skyrme interaction in which the deformed density is replaced by the band averaged scalar density that makes the Hamiltonian rotationally invariant rendering the spectroscopic calculations feasible. It is shown that the introduction of density dependence spreads out the energy spectra and that the Skyrme variant SIV which has a weak density dependence gives best overall agreement for energy spectra and the available data for the electromagnetic properties of the nuclei studied. It is found that the maximum contribution to the energy of any state in the low lying spectrum comes from thes-state attractive ands-state repulsive parts of the Skyrme interaction. It is also shown that when two-body density dependent version of Skyrme interaction is used, the Koopmans theorem no longer holds.     

Fermionic Quantization of Hopf Solitons

In this paper we show how to quantize Hopf solitons using the Finkelstein-Rubinstein approach. Hopf solitons can be quantized as fermions if their Hopf charge is odd. Symmetries of classical minimal energy configurations induce loops in configuration space which give rise to constraints on the wave function. These constraints depend on whether the given loop is contractible. Our method is to exploit the relationship between the configuration spaces of the Faddeev-Hopf and Skyrme models provided by the Hopf fibration. We then use recent results in the Skyrme model to determine whether loops are contractible. We discuss possible quantum ground states up to Hopf charge Q=7.     

Fermionic Quantization and Configuration Spaces for the Skyrme and Faddeev-Hopf Models

The fundamental group and rational cohomology of the configuration spaces of the Skyrme and Faddeev-Hopf models are computed. Physical space is taken to be a compact oriented 3-manifold, either with or without a marked point representing an end at infinity. For the Skyrme model, the codomain is any Lie group, while for the Faddeev-Hopf model it is S². It is determined when the topology of configuration space permits fermionic and isospinorial quantization of the solitons of the model within generalizations of the frameworks of Finkelstein-Rubinstein and Sorkin. Fermionic quantization of Skyrmions is possible only if the target group contains a symplectic or special unitary factor, while fermionic quantization of Hopfions is always possible. Geometric interpretations of the results are given. The first author was partially supported by NSF grant DMS-0204651 The second author was partially supported by EPSRC grant GR/R66982/01     

Rigidly connected magnetic lines: twisting and winding of magnetic lines

The dynamical process of magnetic flux variation in a fluid’s stream tube is described by constructing \(1+1+ (2)\) decomposition of the gradient of fluid’s 4-velocity. The necessary and sufficient conditions are obtained for a spacelike congruence to be a congruence of rigidly connected spacelike curves. The evolution of magnetic flux in a magnetic tube is explored under the assumptions that magnetic lines are rigidly connected and the chemical potential of the fluid is constant along a magnetic tube. The interplay between magnetic and stream tubes is demonstrated. It is shown that the growth of magnetic energy in a magnetic tube cannot exceed to that of a stream tube. It is found that the proper time variation of twist of magnetic lines is caused by gravitation inside a neutron star if magnetic lines are rigidly connected and charge neutrality condition holds. Helmholtz-like magnetic vorticity flux conservation in a magnetic tube constituted by rigidly connected geodetic magnetic lines is derived under the assumption that the charge neutrality condition holds. It is shown that the winding of frozen-in poloidal magnetic field due to differential rotation requires meridional circulation in an axisymmetric stationary hydromagnetic configuration.