摘要:

Here I review vectorial type condensation due to a non zero chemical potential associated to some of the global conserved charges of the theory. The phase structure is very rich since three distinct phases exists depending on the value assumed by one of the zero chemical potential vector self interaction terms. In a certain limit of the couplings and for large chemical potential the theory is not stable. This limit corresponds to a gauge type limit often employed to economically describe the ordinary vector mesons self interactions in QCD. Our analysis is relevant since it leads to a number of physical applications not limited to strongly interacting theories at non zero chemical potential. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1632200

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Gaussian sum‐rules, which are related to a two‐parameter Gaussian‐weighted integral of a hadronic spectral function, are able to examine the possibility that more than one resonance makes a significant contribution to the spectral function. The Gaussian sum‐rules, including instanton effects, for scalar gluonic and non‐strange scalar quark currents clearly indicate a distribution of the resonance strength in their respective spectral functions. Furthermore, analysis of a two narrow resonance model leads to excellent agreement between theory and phenomenology in both channels. The scalar quark and gluonic sum‐rules are remarkably consistent in their prediction of masses of approximately 1 GeV and 1.4 GeV within this model. Such a similarity would be expected from hadronic states which are mixtures of gluonium and quark mesons. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1632201

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

A simple introduction to the topic of three‐state glueball‐meson is given explaining the different limits of the mixing schemes. The generalized Schwinger mass formula and the decay predictions for the different limits are explained. An analytical formula for the valence content is given. It is shown that the lattice QCD results for the decay of a scalar glueball to two pseudoscalar mesons can be explained by a picture where the glueball decays purely via mixing with scalar mesons, which then subsequently decay via the3P0model. This picture predicts dominanta1&pgr; and significant (&pgr;&pgr;)S(&pgr;&pgr;)Sdecay for the lattice scalar glueball. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1632202

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

This talk is based on the work of ref. [1]. Within a non‐linear chiral Lagrangian framework, the mass spectrum ofI= 0 scalar mesons below 2 GeV [&sgr;(550),f0(980),f0(1370),f0(1500) andf0(1710)] is studied, and some speculations on the internal structure of these states is presented. The scalar glueball mass is estimated in the range 1.47–1.64 GeV. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1632203

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

We show that the &kgr;,a0(980), &sgr; and thef0(980) resonances constitute the lightest scalar nonet in three different ways. First, by establishing the continuous movement of the poles from the physical to a SU(3) limit. Second, by performing an analysis of the couplings of the scalar mesons to pairs of pseudoscalars and third, by analysing the couplings of the scalars with two pseudoscalars SU(3) scattering eigenstates. Every of the last two methods agree that the mixing angle between the singlet and the octetI= 0 states is &thgr; = 19° ± 5 degrees, so that the &sgr; is mainly the singlet and thef0(980) the isosinglet octet state. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1632204

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

By comparingSU(3)‐breaking scales of linear mass formulae, it is shown that the lowest vector, axial‐vector, and scalar mesons all have aq¯qconfiguration, while the ground‐state octet and decuplet baryons areqqq. Also, the quark‐level linear &sgr; model is employed to predict similarq¯qandqqqstates. Finally, the approximate mass degeneracy of the scalara0(980) andf0(980) mesons is demonstrated to be accidental. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1632205

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Recent findings on the spectrum of heavy‐quark mesons from computer simulations of quarks and gluons in lattice QCD are summarized, with particular attention to quark‐antiquark states bound by an excited gluon field. The validity of a Born‐Oppenheimer treatment for such systems is discussed. Recent results on glueball masses, the light‐quark 1−+hybrid meson mass, and the static three‐quark potential are summarized. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1632206

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

I describe some insight obtained from a lattice calculation on the possibility that the light scalar mesons areq¯2q2states rather thanq¯q. First I review some general features ofq¯2q2states in QCD inspired quark models. Then I describe a lattice QCD calculation of pseudoscalar meson scattering amplitudes, ignoring quark loops and quark annihilation, which finds indications that for sufficiently heavy quarks there is a stable four‐quark bound state withJPC= 0++and non‐exotic flavor quantum numbers. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1632207

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Techniques for efficient computation of the scalar glueball mass on the lattice are described. Directions and physics goals of proposed future calculations will be outlined. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1632208

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Usinge+e−collision statistics accumulated by CLEO II.V, III detector configurations at CESR we perform Dalitz plot analyses of D‐meson decays into three pseudoscalars. On this Workshop we present recently published and preliminary results of ongoing analyses of the decays,D0 → KS0&pgr;+&pgr;−,D0→ &pgr;+&pgr;−&pgr;0,D0 → KS0&eegr;&pgr;0. The goal of this study is to find out the leading intermediate states for each decay and to present their relative contribution in terms of complex amplitudes and relevant fit fractions. For first observed decays we measure the branching ratios. For the decays with high rate we perform a search for CP violation in terms of integrated rate, fit fractions and complex amplitude parameters. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1632209

出版商:AIP    

年代:1903

数据来源: AIP