THE SYMMETRY OF STRATONS IN

In this paper,the color symmetry of stratons for a theoretical model proposed some times ago is investigated.This symmetry contains two kinds of transformations, the first is color gauge transformations which leave the color mumber of stratons conserved,the second is color permutations which indicate the equivaluence of dif- ferent color stratons.The structure of this symmetry group（S3α）is investigated.The irreducible representations（IR's）of S3α and the reduction of their direct product are given.The relation between IR's of S3α and those of color U（3）group is discussed. In a simplest physical model only two neutral vector gluons are needed and the super-strong ihteraetions among stratons exhibit saturation properties similar to but somewhat different from the case of the Han-Nambu model.Not only the color singlet, but also other color neutral states belonging to IR's 2 or 1 of S3α all belong to the lowest energy level of the super-strong interactions.If there were eight degenerate vector gluons belonging to IR's 2 and 6,the Han-Nambu model would be reproduced.     

DYNAMICAL SYMMETRY BREAKINGS IN QUANTUM CHROMODYNAMICS

Dynamical symmetry breakings in quantum chromodynamics （QCD） are investigated by means of the renormalization-group equations and the Dyson equations. It is shown that: （1） The electromagnetic （and weak） interactions can not be neglected in studying those nonperturbative problems as dynamical symmetry breakings for type-A models in QCD. （2） When the electromagnetic interactions between stratons are taken into account in the weak coupling approximation, dynamical symmetry breakings in QCD occur for many realistic models （type-A models） with QCD asymptotically free. This conclusion may hold beyond the weak coupling approximation of the electromagnetic interactions if there can still be a self-consistent solution of Johnson-Baker-Willey in quantum electrodynamics or β_e has an UV-stable fixed point. e_∞≠0 （a simple zero of β_e） and e_∞is not too large.     

BERRY'S PHASE FACTORS IN MOVING FRAMES OF REFERENCE AND THEIR OBSERVABLE EFFECTS

Under non-relativistic conditions,the properties of adiabatic solutions of the Schrodinger equation in moving frame of reference and the behaviours of the corresponding Berry's Phase are analysed.Two cases of translation and rotation are discussed in detail,which show that the existence of Berry's phase depends on the choice of frame of reference.While Bitter and Dubbers's experiment is explained by the first-order approximation in our discussion,the nonadiabatic effects in this experiment are predicted by the second-order approximation when the adiabatic condition is broken.     

A POSSIBLE FORM OF THE PION'S STRUCTURE FUNCTION

The pion's structure function behaviour is discussed by using the Fock state expansion of the hadronic wavefunction in QCD in this paper. As an example, we employ a model wavefunction of the Fock state in the light-cone and assume a Regge behaviour of a weight function for higher Fock states, and we get a possible form of the pion's structure function. This form is consistent with experimental data of the pion's structure function.     

BETHE-SALPETER EQUATION FOR STRATON AND ANTISTRATON WITH DIFFERENT MASSES AND SU(4)MASS RELATIONS FOR MESONS

In this paper,the theory of mesonic Bethe-Salpeter equation with instantaneousinteraction is generalized to the case where the mass of the straton is not equal tothat of the antistraton.Assuming that the stratons are heavy and the interaction isdominantly a pseudoscalar potential and a static vector potential,we derive the SU(4)mass splitting for mesons.The difficulties encountered by the first order SU(4)massrelations after the discovery of charmed particles are analyzed.It is pointed out thatthese difficulties disappear in our mass relations.In particular,the mass formulaobtained with the potential of harmonic oscillator may explain not only the masses ofboth ground states and radial excited states,but also the effective masses of stratons,while the latter is compatible with the mass values for explaining the magnetic momentsof baryons.Finally,we discuss the newly discovered heavy particle Υ using our mass relations.     

Nonfactorization in D+→K0K+ Decays

We analyze D⁺→K⁰K⁺decay at the leading order, α s corrections with the QCD factorization approach and the soft-gluon effects with the light cone QCD sum rules. We find the prediction of naive factorization is far from the experimental data, and the QCD factorization result approaches to the experimental data. However, in QCD factorization method, if we consider the soft-gluon effects, then the result is in accordance with the experimental data well. Our calculation shows that the soft-gluon contributions which are firstly calculated in D meson nonleptonic decay are noticeable. So, it can't be neglected in the decay channel.     

Geometric scaling as traveling waves

We show the relevance of the nonlinear Fisher and Kolmogorov-Petrovsky-Piscounov (KPP) equation to the problem of high energy evolution of the QCD amplitudes. We explain how the traveling wave solutions of this equation are related to geometric scaling, a phenomenon observed in deep-inelastic scattering experiments. Geometric scaling is for the first time shown to result from an exact solution of nonlinear QCD evolution equations. Using general results on the KPP equation, we compute the velocity of the wave front, which gives the full high energy dependence of the saturation scale.     

String cloud and domain walls with quark matter for a higher dimensional FRW universe in self creation cosmology

In this study, we research a higher dimensional flat Friedmann-Robertson-Walker(FRW) universe in Barber's second theory when strange quark matter(SQM) and normal matter(NM) are attached to the string cloud and domain walls. We obtain zero string tension density for this model. We obtain dust quark matter solutions. This result agrees with Kiran and Reddy, Krori et al, Sahoo and Mishra and Reddy. In our solutions the quark matter transforms to other particles over time. We also obtain two different solutions for domain walls with quark and normal matters by using a deceleration parameter. Also, the features of the obtained solutions are discussed and some physical and kinematical quantities are generalized and discussed. Our results are consistent with Yilmaz, Adcox et al and Back et al in four and five dimensions.     

Simulation of euclidean quantum field theories by a random walk process

A new Monte Carlo method for euclidean lattice field theory is introduced by writing the Boltzmann distribution e^?s as a solution of a diffusion type equation and constructing the associated random walk process. It is practically tested for a quantum mechanical model and a non-compact version of lattice QCD. It is explained where the main interest in this algorithm lies: the diffusion process coming from an action that can be generalized to include non-conservative forces. This possibility is exploited in our QCD version to implement gauge fixing without Faddeev-Popov ghosts.     

A Mechanical Model for Analyzing the Runaway Solutions in the Radiation Reaction Problem

In order to understand the rise of runaway solutions in the radiation reaction problem a mechanical model is used. An alternative demonstration of Daboul’s theorem, through Hurwitz’s criterion, is given. The origin of runaway solutions in electrodynamics is discussed. They arise when the particle has a negative mechanical mass or when approximations are used in the equation of motion. In the 1-dimensional mechanical model an exact and linear equation of motion for the particle is obtained, the corresponding exact solution is again runaway when the mechanical mass is negative. The exact solution is not runaway when the mechanical mass is positive. However, the use of approximations leads to an equation of motion which has runaway solutions. It is exhibited that the use of approximations in the 3-dimensional mechanical model is completely necessary because the general equation of motion for the particle is non-linear. The analysis of this case proceeds in a very similar way to the one carried out in electrodynamics. This means that the number of dimensions also plays an important role in the analysis.     

Saturation and universality in QCD at small x

We find approximate solutions to the renormalization group equation which governs the quantum evolution of the effective theory for the Color Glass Condensate. This is a functional Fokker–Planck equation which generates in particular the non-linear evolution equations previously derived by Balitsky and Kovchegov within perturbative QCD. In the limit where the transverse momentum of the external probe is large compared to the saturation momentum, our approximations yield the Gaussian ansatz for the effective action of the McLerran–Venugopalan model. In the opposite limit, of a small external momentum, we find that the effective theory is governed by a scale-invariant universal action which has the correct properties to describe gluon saturation.     

Relativistic BUU Equation

Based on the Waleck's models QHD-Ⅰ and QHD-Ⅱ describing the nucleon-nucleon interaction,the Boltzmann-Uehling-Uhlenbeck (BUU) equation,which is the time evolution of the nucleon distribution function including the Hartree and Fock self-energy terms as well as the Born collision term and its exchange term,has been derived by using the closed-time path Green's function technique and assuming that the Green's functions and the self-energy terms are slowly varying functions of the centre-of-mass coordinates.Our result shows that the BUU equation for proton and that for neutron are simultaneous each other.     

The QCD pomeron in ultraperipheral heavy ion collisions: I. The double $J/\Psi$ production

The contribution of the QCD pomeron to the process is discussed. We focus on the photon-photon collision, with the quasi-real photon coming from the Weizs?cker-Williams spectrum of the nuclei. We calculate the cross section for this process considering the solution of the LLA BFKL equation at zero momentum transfer using a small t approximation for the differential cross section of the subprocess. Furthermore, the impa ct of non-leading corrections to the BFKL equation is also analyzed. In both cases the cross section is found to increase with the energy, predicting considerable values for the LHC energies. Moreover, we compare our results with the Born two-gluon approximation, which is energy independent at the photon level. Our results indicate that the experimental analyses of this process can be useful to discriminate the QCD dynamics at high energies. Received: 12 December 2002 / Published online: 7 March 2003 RID="a" ID="a" e-mail: barros@ufpel.tche.br RID="b" ID="b" e-mail: magnus@if.ufrgs.br     

Direct pion emission in D*~+→D~+π decays

The QCD multipole expansion(QCDME) is based on quantum field theory and has been extensively applied to study transitions among Υ and ψ family members. As it refers to non-perturbative QCD, however, it has only a certain application range. Even though it successfully explains the transition data among members of the Υ(ψ) family, as Eichten indicates, beyond the production threshold of mediate states it fails to match data by several orders of magnitude. In this work, by studying a simple decay mode D*→D +π~0, where a pion may be emitted before D* transitions into D, we analyze the contribution of QCD multipole expansion. As the Dπ portal is open,the dominant contribution is an OZI-allowed process where a light quark-pair is excited out from vacuum, and its contribution can be evaluated by the ~3P_0 model. Since direct pion emission is OZI-suppressed and violates isospin conservation, its contribution must be much smaller than the dominant one. By a careful calculation, we estimate that the QCDME contribution should be 3–4 orders smaller than the dominant contribution and this result can offer a quantitative interpretation for Eichten's statement.     

QCD JET IN POLARIZED e+e－ ANNIHILATION

Following perturbative QCD theory, the two-jet and three-jet angular distributions in polarized e⁺e^－ annihilation is computed using the dimensional regularization scheme. The azimuthal inhomogeneity caused by the polarization is discussed. We also compute the exact formulae of dependence on ε´,δ to the second order and discuss the correction to G.Sterman and S.Weinberg's result.     

Quantum chromodynamics

Quantum Chromodynamics (QCD) is a quantum field theory of the strong interaction with non-abelian gauge fields mediating the interactions between quarks. The experimentally observed strong interactions are to be epiphenomena of these fundamental interactions. The experimental successes of QCD form the basis for our present optimism that a theory of the strong force has been found. However, QCD is still very vulnerable to default on both experimental and theoretical grounds. In this article we offer the reader a review of the properties and attempted solutions of QCD. Each section of this review can be read independently of the others. In the introduction we describe the properties of QCD and the hoped for confinement and PCAC phase transitions. This is followed by a section on the renormalization of non-abelian gauge field theories: the functional methods and the path integral, the BPHZ program, the BRS transformation and proof of renormalizability, the Slavnov-Taylor identities and Schwinger-Dyson equations. The renormalization group equations are derived and applied to physical processes. Two dimensional prototypes of QCD, the abelian Schwinger model and 2-D QCD, are reviewed. An extensive review of the perturbative development of QCD is given with emphasis on infrared divergences, exponentiation of leading logarithms, the Cornwall-Tiktopoulos equation and a non-perturbative approach to QCD. A self contained section on topological solitons follows with discussions of homotopy theory, vortices, monopoles and especially instantons, and the periodic vacuum. Recent results, the attempt to study phase transitions in QCD using the dilute gas approximation and Borel resummations in QCD, are examined. Most of the major areas of interest in QCD are covered in this review; the prime exceptions are lattice gauge theories and phenomenological QCD like the parton and potential models.     

WHAT IS THE NATURE OF THE NEWLY DISCOVERED HEAVY PARTICLE γ(9.5)

In this paper, we discuss the nature of the newly discovered heavy particle Y（9.5）. Five possibilities of experimental criteria are analysed. We show that if Y is a heavy photon, an intermediate boson, a bound state of straton-antistraton or a hadron without valence stratons, and all the Γee will differ by several orders of magnitude and can therefore be discriminated easily in e⁺ e^-collision experiments. The width value Fee and its ratio of γ to γ' are not identical for the case of colour excited states of meson and the case of bound states of the new straton-antistraton. The masses of other existing new particles can also be predicted. In particular, the masses of weakly decaying heavy particles are not the same for these two cases, which may be regarded as a criterion to discriminate between these two cases. We have also discussed the main decaying properties of γ for these five possibilities.