摘要:

In this contribution I review some recent developments in light quark spectroscopy, from a somewhat theoretical viewpoint. I concentrate almost exclusively on lightmesons, since this area of hadron physics has seen the greatest share of recent advances. In theory I will discuss recent LGT results for hybrid meson masses, hybrid decay calculations and conventional quarkonium decay calculations. In experiment I review new or recent candidates for higher quarkonium states (the new experimental hybrid candidates are reviewed by other contributers in these proceedings), and then discuss an interesting miscellany in &ggr;&ggr; physics,K1mixing angles,KK¯molecules andDsdecays. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.55993

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The Crystal Barrel experiment has continued its program to clarify the nature of low mass resonances. Results from final states with high multiplicity or containing kaons (partly rendered possible by a hardware upgrade—a silicon microstrip detector), and annihilation in flight (in which the rest frame energy is extended up to 2.4 GeV) are presented. In addition, several tests of chiral perturbation theory, usingp¯pannihilation as a meson factory, are summarized. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.56023

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The experiments carried out with the SND detector at VEPP-2Me+e−collider are described. The total integrated luminosity, collected in the energy range around &fgr;(1020) peak is about 4 pb−1and in the energy range2E=1040–1400 MeV—6.5 pb−1.Preliminary results are presented for &fgr;(1020) rare decays, including&fgr;→&eegr;′&ggr;,&ohgr;&pgr;o,&pgr;o&pgr;o&ggr;,&eegr;&pgr;o&ggr;,and for &eegr;(550) decays&eegr;→e+e−,2&pgr;o.©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.56028

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Partial wave analysis results of centrally produced mesons in the reactionpp→pslow(X)pfast,with 800 GeV/c protons incident on a liquid hydrogen target are presented. In the reactions considered in this paper the (X) system decays into: a)Ka0K±&pgr;∓,b)KsKs,and c)&pgr;+&pgr;−.©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.55997

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

In this talk, the analysis results onJ/&psgr;→&ggr;&pgr;0&pgr;0,&ggr;&eegr;&eegr;,&ggr;&eegr;&eegr;′and&ggr;&eegr;′&eegr;′,based on BES9.0×106 J/&psgr;data, are reported and the evidences for the existence of &xgr;(2230) are presented. The results forJ/&psgr;→&ggr;&pgr;+&pgr;−&pgr;+&pgr;−,using the partial wave amplitude analysis (PWA), are obtained. We also reported the analysis results from&khgr;cJdecays. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.56029

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Increasing luminosity at HERA now offers the possibility to study ep scattering close to the kinematic limit, given by the available center-of-mass energy of 300 GeV, and to investigate rare event topologies with sufficient statistics. In this context H1 and ZEUS both have reported an excess of events at very high momentum transfersQ2in thee+pdata recorded up to the end of 1996. Here a preliminary update of the H1 highQ2analysis is presented, including data from the first half of 1997, almost doubling the integrated luminosity of the already published result. In addition, we report on an analysis searching for events with an imbalance in transverse momentumpt.While the majority of events show topologies typical for charged current processes, five have been observed with an isolatede−or&mgr;±with largept.The corresponding Standard Model expectation from W production with subsequent decay into leptons is 1.75 events. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.56027

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

In this talk I report on the latest results of the ZEUS collaboration concerning the cross sections in both charged current and neutral current channels at high(x,Q2),together with the comparison with expectations. The data set corresponds to an integrated luminosity of 33.5 pb−1. The results are those given at the 1997 Lepton-Photon Conference and update the earlier publication. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.56030

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Recent contributions from LEP to the field of hadron spectroscopy are reviewed. Important results have come from three distinct classes of physics processes: inclusive meson and baryon production in hadronicZ0decay; hadronic systems in &tgr; lepton decay; and resonance formation in untagged &ggr;&ggr; collisions. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.56031

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

I describe recent work by the SLD Collaboration in various studies of hadron production inZ0decays. By exploiting SLD’s precision vertex detector and particle identification capabilities to tag primary jet flavour and SLC’s polarisation to separate quark from anti-quark jets, we have made systematic comparisons of the flavour-dependence of hadron production rates and made an improved test of the flavour-independence of&agr;s.We also measured the gluon energy spectrum inbb¯gevents and theb-quark fragmentation function and made a precision measurement of theB0andB+meson lifetimes. ©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.56032

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

We present evidence fora0(1450)decaying toKK¯inp¯pannihilation at rest in liquid hydrogen in the final stateKLK±&pgr;∓.This reaction is important for the study of theKK¯decay mode of scalar resonances, in particular the isovectorsa0(980)anda0(1450).The determination of thea0(1450)production also fixes theKK¯coupling of the isoscalarf0(1500).We findB(p¯p→a0(1450)&pgr;;a0(1450)→KK¯)=(8.88±1.68)⋅10−4and henceB(p¯p→f0(1500)&pgr;;f0(1500)→KK¯)=(4.52±0.36)⋅10−4.©1998 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.56024

出版商:AIP    

年代:1998

数据来源: AIP