摘要:

A brief and biased overview of the status of the constituent quark model is presented. We concentrate on open issues and goals of hadronic phenomenology, rather than specific physics conundrums in the field. Modern attempts at addressing these issues are also presented. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1482461

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

The relativistic quark model is presented. The quark‐antiquark potential for the Schro¨dinger‐like equation is constructed with the account of retardation effects and one‐loop radiative corrections. It consists of the one‐gluon exchange part and the confining part which is the mixture of the Lorentz scalar and Lorentz vector contributions. The latter contains both the Dirac and Pauli terms. In thev2/c2approximation the mass spectra of heavy quarkonia (charmonium and bottomonium) are calculated in good agreement with experiment. In the case of heavy‐light mesons (BandD) the light quark is treated completely relativistically and only the expansion in the inverse heavy quark mass is used. The mass spectra of the ground and excited states ofD,Ds,B,Bsmesons are calculated. They exhibit some features of the so‐called “level inversion.” The obtained results are generally in accord with experimental data. Still there exist some discrepancies between measurements of different collaborations. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1482462

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

The &psgr;(2S) total decay width, partial widths to hadrons, &mgr;+&mgr;−, &pgr;+&pgr;−J/&psgr; final states and corresponding branching ratios are measured with a scan experiment in the vicinity of &psgr;(2S) resonance at the BES. The preliminary results give much improved accuracies compared with existing data. Also reported are the branching ratios for &psgr;(2S) to &tgr;‐pair and radiative decays. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1482463

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

The spectrum ofqq¯states observed in Crystal Barrel data in flight is very simple: a set of parallel straight‐line trajectories of mass squared v. radial excitation number. There are 6 extra states, making candidates for 4 glueballs and 2 hybrids. Mass ratios of glueball candidates agree closely with the latest Lattice Gauge calculations. The evidence for 2−+hybrids &eegr;2(1860) and &pgr;2(1880) is reviewed. Further data from a polarised target are highly desirable in channels 3&pgr;0, &eegr;&pgr;0, &ohgr;&pgr;0and &ohgr;&eegr; in order to separate cleanly triplet states withL=J± 1. These data would provide precise measurements of tensor, spin‐orbit and spin‐spin splitting of masses. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1482464

出版商:AIP    

年代:1902

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.1482465

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

The methods used by the four LEP experiments to select W pair events are briefly reviewed, as well as the main methods for extracting the W mass and width. The currently relevant and in some cases still open systematic issues are illustrated. The preliminary results based on approximately 2500 pb−1collected from 1996 to 2000, have been combined to giveMW= 80.450 ± 0.039 GeV/c2and &Ggr;W= 2.150 ± 0.091 GeV/c2. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1482466

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

Experimental results on QCD measurements obtained in recent analyses and based on data collected with CDF Detector from the Run 1b Tevatron running cycle are presented. The scope of the talk includes major QCD topics: a measurement of the strong coupling constant &agr;s, extracted from inclusive jet spectra and the underlying event energy contribution to a jet cone. Another experimental object of QCD interest, prompt photon production, is also discussed and the updated measurements by CDF of the inclusive photon cross section at 630 GeV and 1800 GeV, and the comparison with NLO QCD predictions is presented. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1482467

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

Here we report partial wave analysis results forJ/&psgr; →pp¯&eegr; based on 7.8 × 106BES IJ/&psgr; events, and through which we determined twoN*resonancesN*(1535)S11andN*(1650)S11. BES just finished collecting 5 × 107J/&psgr; events. Some very preliminary results are presented from the 2.4 × 107J/&psgr; events, namely the first new data set and showed the high statistics and good data quality of the newJ/&psgr; data. Using the 2.4 × 107J/&psgr; events, we performed the partial wave analysis inJ/&psgr; → &ggr;K+K−, and the results showed that the 0++component is dominant in the mass region around 1.7 GeV. This conclusion is consistent with other experiments. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1482468

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

The Hall D experiment at Jefferson Lab is part of the proposed CEBAF upgrade to 12 GeV beam energy. The Experiment will study gluonic excitations of mesons in the 1.5 to 2.5 GeV/c2mass region using an 8 to 9 GeV beam of linearly polarized photons. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1482469

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

Experiments with antiprotons at LEAR and FermiLab have started a new era in hadron spectroscopy. Candidates for bound states with gluonic degrees of freedom were found and the spectroscopy in the charmonium region has reached a new level of precision. It is planned to extend measurements of this kind at GSI/Darmstadt. Antiprotons with energies up to 15 GeV will interact with a Hydrogen cluster target in a storage ring with high luminosity. The machine and the detector will be discussed together with the physics program. The main emphasis will be on the search for missing charmonium states and for charmed hybrids, but the large production rate ofDD¯‐pairs will also allow searches for rare D‐decays and for CP‐violation in the charm system. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1482470

出版商:AIP    

年代:1902

数据来源: AIP