Meson spectrum in a relativistic harmonic model with instanton-induced interaction

On the basis of the phenomenological relativistic harmonic model for quarks, we have obtained the ground-state masses of the light pseudo-scalar and vector mesons. The full Hamiltonian used in the investigation has Lorentz scalar + vector confinement potential, along with one-gluon-exchange potential (OGEP) and the instanton-induced quark-antiquark interaction. A good agreement is obtained with the experimental masses. The respective role of instanton-induced interaction and OGEP for the determination of the meson masses is discussed.Received: 18 October 2002, Revised: 13 January 2003, Published online: 23 December 2003PACS: 12.39.Ki Relativistic quark model - 12.39.Pn Potential models - 14.40.Aq , K, and mesonsS. Pepin: Present address: rue de Sluse 13, B-4000 Liége, Belgium     

Noether‘s theorem of a rotational relativistic variable mass system

Noether‘s theory of a rotational relativistic variable mass system is studied.Firstly,Jourdain‘s principle of the rotational relativistic variable mass system is given.Secondly,on the basis of the invariance of the Jourdain‘s principle under the infinitesimal transformations of groups,Noether‘s theorem and its inverse theorem of the rotational relativistic variable mass system are presented.Finally,an example is given to illustrate the application of the result.     

Approximately relativistic center-of-mass variables for a system of two interacting particles

A canonical transformation is found that enables one in the first quasirelativistic approximation (which takes into account orders c^–2) to separate the internal motion in a classical system of two particles from its motion as a whole in the case of arbitrary interaction between the particles.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 49–53, October, 1980.     

Wigner functions for two arbitrary operators and spectrum perturbation

We have concentrated on the Wigner function for the photon number and a quadrature operator, which we find to differ from zero outside the spectrum of the photon number operator. We have provided an illustration with a coherent state.     

Wave functions and spectrum in hot electroweak matter for large Higgs masses

We present results for the wave functions and the screening mass spectrum for quantum numbers , and in the three-dimensional SU(2)–Higgs model near to the phase transition line below the endpoint and in the crossover region. Varying the 3D gauge couplings we study the behaviour along a line of constant physics towards the continuum limit in both phases. In the crossover region the changing spectrum of screening states versus temperature is examined showing the aftermath of the phase transition at lower Higgs mass. Different to smearing concepts we used large sets of operators with various extensions allowing to identify wave functions in position space. Received: 4 August 1998 / Published online: 2 November 1998     

Geometric phase for a coupled two quantum dot system

The adiabatic geometric phase is calculated in a coupled two quantum dot system, which is entangled through Förster interaction. This phase is then utilized for implementing basic quantum logic gate operation useful in quantum information processing. Such gates based on geometric phase provide fault-tolerant quantum computing.     

Determination of the mass spectrum and the decay constant mesons consisting of c and b quarks

On the basis of an investigation into the asymptotic behavior of the correlation functions of the corresponding field currents with the necessary quantum numbers, an analytic method for determining the mass spectrum and decay constants of mesons consisting of c and b quarks with relativistic corrections is proposed. The dependence of the constituent mass of quarks on the current mass and on the orbital and radial quantum numbers is analytically derived. The mass and the wave function (WF) mesons are determined from the Schrodinger equation with a mass of constituent components particles. We calculate the splitting of the mass spectrum for the singlet and triplet states mesons, as well as to determine the width of the lepton and radiation decays due E1 transition for $\left( {\bar cc} \right)$ , $\left( {\bar bb} \right)$ , $\left( {\bar bc} \right)$ systems. Our results for the mass spectrum of mesons consisting of c and b quarks are in satisfactory agreement with the available experimental data.     

Nonlocal interaction of spinor and pseudoscalar fields

The nonlocal interaction of a spinor and a pseudoscalar field is considered in the framework of gradient coupling. By the introduction of a relativistically invariant form factor in the neutrino propagator, renormalizability of the theory is achieved. It is shown that the number of primitive diagrams is just four, one of which is the neutrino self-energy diagram. The Pauli-Villars regularization procedure is carried out for this diagram.This paper was presented at the session of the Nuclear Physics Section of the USSR Academy of Sciences in Moscow (February 1–4, 1978).Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 84–88, July, 1980.We are grateful to G. V. Efimov and N. Atakishiev for discussing the results.     

Hyperchaos of two coupled Bose--Einstein condensates with a three-body interaction

We investigate the dynamics of two tunnel-coupled Bose--Einstein condensates (BECs) in a double-well potential. The effects of the three-body recombination loss and the feeding of the condensates from the thermal cloud are studied in the case of attractive interatomic interaction. An imaginary three-body interaction term is considered and a two-mode approximation is used to derive three coupled equations which describe the total atomic numbers of the two condensates, the relative population and relative phase respectively. Theoretical analyses and numerical calculations demonstrate the existence of chaotic and hyperchaotic behaviour by using a periodically time-varying scattering length.     

Determination of the glueball mass with allowance for the relativistic character of interaction

Nonperturbative corrections to an interaction Hamiltonian that are associated with relativistic motion and a large coupling constant are determined on the basis of an investigation of the asymptotic behavior of the polarization loop for charged scalar particles in an external gauge field. The mass spectrum of a bound state is determined analytically. The mechanism responsible for the emergence of the constituent mass of particles that form a bound state is explained. It is shown that the contribution of the vector potential and the contribution of the potential associated with a nonperturbative character of interaction cancel each other and that the slope of the Regge trajectory is determined in terms of the string tension.     

Study of the Lie symmetries of a relativistic variable mass system

The differential equations of motion of a relativistic variable mass system are given.By using the invariance of the differential equations under the infinitesimal transformations of groups,the determining equations and the restriction equations of the Lie symmetries of a relativistic variable mass system are built,and the structure equation and the conserved quantity of the Lie symmetries are obtained.Then the inverse problem of the Lie symmetries is studied.The corresponding Lie symmetries are found according to a known conserved quantity.An example is given to illustrate the application of the result.     

Isgur-Wise functions for confined light quarks in a colour electric potential

We explore the influence on the Isgur-Wise function of the colour electric potential between heavy and light quarks in mesons. It is shown that in bag models, its inclusion tends to restore light quark flavour symmetry relative to the MIT bag predictions, and that relative to this model it flattens the Isgur-Wise function. Results compare very well with observations.Work supported in part (M.S.) by the KBN grant no. 20-38-09101. We also thank the Norwegian Research Council for a travel grant     

Massive narrow resonance solutions of strongly coupled relativistic particles: a mechanism of mass generation

By explicit solutions of the relativistic wave equation corresponding to strong singular (nonrenormalizable) magnetic dipole interactions, we show how very massive almost stable reonances, as well as normalizable stable states, can be formed from light or massless fermionic constituents.     

A parameterization of electro-weak mass matrices for quarks

We discuss quark flavor mixing and CP violation using a 10 parameter quark mass matrix in the electro-weak basis. The matrix handles the high mass of the top quark, 174±16 GeV, and contains two CP violating phases. We show that this scheme favors minimal CP violation by a single phase factor and leads to maximal CP violation in the standard parameterization of the quark flavor mixing matrix.     

The consistent Riccati expansion and new interaction solution for a Boussinesq-type coupled system

Starting from the Davey–Stewartson equation,a Boussinesq-type coupled equation system is obtained by using a variable separation approach.For the Boussinesq-type coupled equation system,its consistent Riccati expansion(CRE)solvability is studied with the help of a Riccati equation.It is significant that the soliton–cnoidal wave interaction solution,expressed explicitly by Jacobi elliptic functions and the third type of incomplete elliptic integral,of the system is also given.     

Energy spectrum and entanglement of two tunnel- coupled Bose--Einstein condensates

This paper obtains the energy-spectrum and eigenstate corrections of two-mode Bose--Einstein condensates (BECs) coupled by quantum tunnelling by perturbation method in both strong and weak tunnelling regions. The population imbalance between two BECs are then studied in terms of the low-lying eigenstates which also characterize the intrinsic entanglement between the two-mode BECs. The strong parity effect in the weak tunnelling region is also investigated.