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.     

A Maple Package to Compute Lie Symmetry Groups and Symmetry Reductions of （1＋1）-Dimensional Nonlinear Systems

Armed with the computer algebra system Maple, using a direct algebraic substitution method, we obtain Lie point symmetries, Lie symmetry groups and the corresponding symmetry reductions of one component nonlinear integrable and nonintegrable equations only by clicking the ‘Enter＇ key. Abundant （1＋1）-dimensional nonlinear mathematical physical systems are analysed effectively by using a Maple package LieSYMGRP proposed by us.     

TWO PHOTONS EXCITED 4d RYDBERG STATE OF AsH3

In this paper, by using resonance enhanced (2+1) multiphoton ionization (REMPI) of AsH₃ and detecting the daughter molecular ions AsH⁺ and As⁺, a long progression discrete structure was obtained from 267 to 291 nm, which obeys the formula ν₀(cm^-1)=68875.3+504.1v′₂+5.26v′²₂. Analysis of the spectrum has revealed that it belongs to 4d Rydberg state transition. Our assignment yields the 4d Rydberg state parameters T_e′=67881.1 cm^-1, ω_e′=495.1 cm^-1 and δ=0.962. Finally the 4d Rydberg state structure of AsH₃ was discussed.     

FIRST-PRINCIPLE SELF-CONSISTENT PSEUDOPOTENTIAL CALCULATION OF THE ELECTRONIC STRUCTURES OF SHORT-PERIOD (GaAs)m(AlAs)n SUPERLATT1CES

With the local density approximation, the band structares of the short-period (GaAs)₁(AlAs)₁ and (GaAs)₂(AlAs)₁ superlattices are calculated by using the first-principle self-consistent pseudopotential method. The results show that the (GaAs)₁(AlAs)₁ superlattice is an indirect semiconductor, and the lowest conduction band state is at point R in the Brillouin zone; the (GaAs)₂(AlAs)₁ superlattice is a direct semiconductor and the lowest conduction band state is at point Γ. The squared matrix elements of transition are calculated. The pressure coefficients of energy gaps of the (GaAs)₁(AlAs)₁ and (GaAs)₂(AlAs)₁ superlattices are calculated and compared with those obtained by hydrostatic pressure experiments.     

Observational constraints on the accelerating universe in the framework of a 5D bounce cosmological model

In the framework of a five-dimensional (5D) bounce cosmological model, a useful function f(z) is obtained by giving a concrete expression of deceleration parameter q(z)=q₁+{q₂}/{1+ln (1+ z)}. Then using the obtained Hubble parameter H(z) according to the function f(z), we constrain the accelerating universe from recent cosmic observations: the 192 ESSENCE SNe Ia and the 9 observational H(z) data. The best fitting values of transition redshift z_T and current deceleration parameter q₀ are given as z_T= 0.65_-0.12^0.25 and q₀ = - 0.76_-0.15^+0.15 (1σ). Furthermore, in the 5D bounce model it can be seen that the evolution of equation of state (EOS) for dark energy w_de can cross over -1 at about z=0.23 and the current value w_0de= - 1.15<- 1. On the other hand, by giving a concrete expression of model-independent EOS of dark energy w_de, in the 5D bounce model we obtain the best fitting values z_T= 0.66_0.08^+0.11 and q₀ = - 0.69_0.10^+0.10 (1σ) from the recently observed data: the 192 ESSENCE SNe Ia, the observational H(z) data, the 3-year Wilkinson Microwave Anisotropy Probe (WMAP), the Sloan Digital Sky Survey (SDSS) baryon acoustic peak and the x-ray gas mass fraction in clusters.     

Conformal invariance and integration of first-order differential equations

This paper studies a conformal invariance and an integration of first-order differential equations. It obtains the corresponding infinitesimal generators of conformal invariance by using the symmetry of the differential equations, and expresses the differential equations by the equations of a Birkhoff system or a generalized Birkhoff system. If the infinitesimal generators are those of a Noether symmetry, the conserved quantity can be obtained by using the Noether theory of the Birkhoff system or the generalized Birkhoff system.     

Production of Squeezed State of Single Mode Cavity Field by the Coupling of Squeezed Vacuum Field Reservoir in Nonautonomous Case

The dissipative and decoherence properties as well as the asymptotic behaviour of the single mode electromagnetic field interacting with the time-dependent squeezed vacuum field reservoir are investigated in detail by using the algebraic dynamical method. With the help of the left and right representations of the relevant hw(4) algebra, the dynamical symmetry of the nonautonomous master equation of the system is found to be su(1, 1). The unique equilibrium steady solution is found to be the squeezed state and any initial state of the system is proven to approach the unique squeezed state asymptotically. Thus the squeezed vacuum field reservoir is found to play the role of a squeezing mold of the cavity field.     

Transport Properties in a One—Dimensional Chain with Randomly Side—Coupled Impurities

We investigate the transport properties of a one-dimensional(1D) chain with randomly side-coupled impurities,By using the transfer matrix technique,we present numerical results of the transmission coefficient as a function of the electron energy,It is found that an extended state will be shown in such a random 1D system if the impurities are side-coupled to the chain with not only the nearest-neighbour bonds but also the next-nearestneighbour bonds.We present an analytical expression for the energy of this extended state,which is determined by the strength of the nearest and next-nearest couplings between the impurities and the chain.The obtained results can be used to explain the transport properties of DNA chains and other quasi-1D organic structures.     

Infrared diode laser spectroscopy of O2–N2O van der Waals complex in the ν1 symmetric stretch region of N2O

The rovibrational spectrum of O₂–N₂O van der Waals complex is measured in the v₁ symmetric stretch region of N₂O monomer using a tunable diode laser spectrometer. The complex is generated by a slit-pulsed supersonic expansion with gas mixtures of O₂, N₂O, and He. Both a- and b-type transitions are observed. The effective Hamiltonian for an open-shell complex consisting of a diatomic molecule in a ³Σ electronic state and a closed-shell partner is used to analyze the observed spectrum. Molecular constants in the vibrationally excited state are determined accurately. The band-origin of the spectrum is determined to be 1284.7504(25) cm^-1, red-shifted from that of the N₂O monomer by ～ 0.1529 cm^-1.     

Quantum Cloning of Steering

Quantum steering in a global state allows an observer to remotely steer a subsystem into different ensembles by performing different local measurements on the other part. We show that, in general, this property cannot be perfectly cloned by any joint operation between a steered subsystem and a third system. Perfect cloning is viable if and only if the initial state is of zero discord. We also investigate the process of cloning the steered qubit of a Bell state using a universal cloning machine. ...     

Spontaneous U（1） Symmetry Breaking in Coupled Bose System

Adding a U(1) symmetry breaking term V^1/2 a(λ₁a₀+λ*₁a^&#8224;₀)+V^1/2(λ₂b₀+λ^*₂b^&#8224;₀) to Bogoliubov's truncated Hamiltonian H_B for a weakly interacting coupled Bose system, by using the mean-field approximation rather than the c-number approximation, we find that, via a Feshbach resonance at zero temperature, the states of the coupled Bose system are generalized SU(1,1) × SU(1,1) coherent states. The Bose-Einsteincondensation occurs in response to the spontaneous U(1) symmetry breaking.     

The multiphoton ionization spectrum of jet-cooled pyrimidine in the 3p Rydberg and B1 (π,n) states

Resonance-enhanced multiphoton ionization (REMPI) has been applied to study the n → 3p Rydberg transition of pyrimidine (jet-cooled sample and mass resolved spectrum). Only the one component, the 3p_z(B₂), appears in the (2 + 1) REMPI and the active vibrations are ν_6a = 622, ν₁ = 946, and ν_9a = 1116 cm⁻¹. The symmetry of the state was determined by polarization measurements (linear, circular polarization). The first (π^∗,n) ³B₁ triplet state appears as a one-photon resonance in the three-photon ionization process.     

Laser excitation spectrum of PbO: Rotational analysis of the a(1)-X(0+) system

A flashlamp-pumped tunable dye laser has been used to investigate the a-X band system of PbO. Spectra with resolution adequate for rotational analysis were obtained by exciting a-X photoluminescence with the laser operating at a bandwidth of 0.2 cm^?1. The (3,1) and (4,1) bands have been rotationally analyzed, providing the rotational constants B₃ = 0.2389 ± 0.0002 cm^?1 and B₄ = 0.2374 ± 0.0002 cm^?1 for the a state. Observation of P, Q, and R branch structure confirms the assignment of the a state as a Hund's case (c), $\text{Ω}\text{= 1}$ state of PbO. Calculated combination defects having positive algebraic sign support the presence of a b(0^?) state approximately 350 cm^?1 above the a(1) state.     

吡啶B1(nπ*)态(2+3)偏振共振多光子电离谱中6a10带型模拟及转动常量确定

通过模拟吡啶B₁(nπ^*)态(2+3)偏振共振多光子电离谱中转动结构可部分分辨的6a¹₀带型,获得了该态上吡啶分子的转动常量,分别为A′=0.21670cm^-1,B′=0.16758cm^-1,C′=0.09450cm^-1.表明氮原子上的一个孤对电子跃迁进入π^*轨道后氮原子自身电负性减弱,吡啶分子构架总体上张开.此外,比较6a^关键词：     

A High Resolution Luminescence Study of two Novel Salts of the Triethvlenetetraaminehexaacetatoeuropate(III) Anion

A low-temperature high-resolution luminescence study of K₃Eu(TTHA)·H₂O and T1₃Eu(TTHA) ·H₂O has been carried out. the Eu³⁺ luminescence spectrum was recorded over the spectral range which includes transitions from the ⁵D₀ excited state to the ⁷F_0-4 ground state manifolds. the observed spectral patterns are analyzed using group theoretical methods so as to deduce the site symmetry of the Eu³⁺ ion in the complex. the analysis shows that the Eu³⁺ ion occupies a spectroscopic site symmetry that approaches a D₂ symmetry with distortion towards a C₂ or lower symmetry in the potassium salt and a site symmetry of a C₃ in the thallium salt. These salts illustrate the potential of the counterion to markedly influence the effective site symmetry of the Eu³⁺ ion.     

The a-X electronic band system of selenium monoxide at 1.8 μm

The emission spectrum of the SeO molecule excited in a microwave discharge and recorded at low resolution revealed the existence of a brief band system in the near-infrared region 6470-5560 cm^?1. The system consists of five bands divided into two groups which were assigned as the Δv = 0 and +1 sequences of the transition a2-X₂1 (X being the case ?c³Σ^? ground state). An approximate value of the rotational constant B₀ of state a was obtained from the observed separation between the Q and R heads of the 0-0 band and the known value of B₀ of state X. The derived molecular parameters of state a are: ν₀₀ = 5566.2 cm^?1, $\text{Δ}\text{G(}\text{1}\text{2}\text{) = 833.3}\text{cm}{}^{\mathrm{?1}}$, B₀ = 0.45₆ cm^?1.     

Rotational analysis of visible bands of nitrogen dioxide using polarization spectroscopy

Polarization labeling spectroscopy is used to simplify the visible absorption spectrum of NO₂. State-selected spectra of the ²B₂-²A₁ transition in the range 16 600–17 000 and 17 350–17 850 cm^?1 are developed using a narrow-band pump operated (1) near 545 nm, where the pumped transitions also belong to the ²B₂ system, and (2) near 436 nm on a selected transition of the ²B₁-²A₁ (Douglas-Huber) band system. Rotational analyses are given for the K_a = 0 and K_a = 1 subbands of 11 vibronic bands and limited observations reported for the K_a = 0 or 1 manifold of a further 8 bands. Polarization-labeling experiments within the ²B₁-²A₁ band system are also described.     

Unitarity bounds in the vector condensate model of electroweak interactions

We replace the standard model scalar doublet by a doublet of vector fields and generate masses by dynamical symmetry breaking. Oblique radiative corrections are small if the new vector bosons (B ⁺,B ⁰) are heavy. In this note it is shown that the model has a low momentum scale and above Λ?2 TeV it does not respect the perturbative unitarity. From tree-graph unitarity the allowed region ofB ⁺ (B ⁰) mass is estimated asm _B ⁺≥333 GeV (m _B ⁰≥373 GeV) at Λ=1 TeV.     

The pure rotational spectrum of ZnO in the XΣ and aΠi states

The pure rotational spectrum of ZnO has been measured in its ground X¹Σ⁺ and excited a³Π_i states using direct-absorption methods in the frequency range 239-514 GHz. This molecule was synthesized by reacting zinc vapor, generated in a Broida-type oven, with N₂O under DC discharge conditions. In the X¹Σ⁺ state, five to eight rotational transitions were recorded for each of the five isotopologues of this species (⁶⁴ZnO, ⁶⁶ZnO, ⁶⁷ZnO, ⁶⁸ZnO, and ⁷⁰ZnO) in the ground and several vibrational states (v = 1-4). Transitions for three isotopologues (⁶⁴ZnO, ⁶⁶ZnO, and ⁶⁸ZnO) were measured in the a³Π_i state for the v = 0 level, as well as from the v = 1 state of the main isotopologue. All three spin-orbit components were observed in the a³Π_i state, each exhibiting splittings due to lambda-doubling. Rotational constants were determined for the X¹Σ⁺ state of zinc oxide. The a³Π_i state data were fit with a Hund’s case (a) Hamiltonian, and rotational, spin-orbit, spin-spin, and lambda-doubling constants were established. Equilibrium parameters were also determined for both states. The equilibrium bond length determined for ZnO in the X¹Σ⁺ state is 1.7047 Å, and it increases to 1.8436 Å for the a excited state, consistent with a change from a π⁴ to a π³σ¹ configuration. The estimated vibrational constants of ω_e ∼ 738 and 562 cm⁻¹ for the ground and a state agreed well with prior theoretical and experimental investigations; however, the estimated dissociation energy of 2.02 eV for the a³Π_i state is significantly higher than previous predictions. The lambda-doubling constants suggest a low-lying ³Σ state.     

Time-dependent self-consistent perturbation theory and applications to molecules

The two most intense bands of the 370 nm electronic band system of tropolone have been rotationally analysed. They are separated by 18·93 cm^-1 and it has been shown that the high wavenumber band is the 0^--0^- (H₁ ¹) transition in what is almost certainly the internal hydrogen-bonding vibration v _H : the low wavenumber band is the 0⁺-0⁺ (0₀ ⁰) transition. A rotational contour analysis of both bands shows that there is an intensity alternation in K _a″ such that the ratio K _a″ even : odd is 10 : 6 in the 0⁺-0⁺ band and 6 : 10 in the 0^--0^- band. The intensity alternation, the nearly equal intensities of the 0⁺-0⁺ and 0^--0^- bands, the separation of these two bands and the anharmonic behaviour of v _H show that the separation of the 0⁺ and 0^- levels is small in the ground electronic state (probably less than 50 cm^-1) and is 18·93 cm^-1 larger in the excited electronic state.

The 0⁺-0⁺ and 0^--0^- bands are both type B showing that the electronic transition is à ¹ B ₂-X ¹ A ₁ and therefore π*-π rather than π*-n. The π*-n transition is probably shifted to high wavenumber by the internal hydrogen-bonding.