摘要:

Recent PETRA experiments to test QED are shown to provide non‐trivial information on the structure of weak neutral‐current interactions.

ISSN:0094-243X    

DOI:10.1063/1.2947487

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

1. The evidence from e+e−collisions for QCD's gluons is considered. The criterion for a convincing experimental test is that plausible alternative scenarios fail to describe data.2. Future experiments to establish the gauge nature of QCD are discussed.

ISSN:0094-243X    

DOI:10.1063/1.2947485

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The low energy phenomenological implications of theories with dynamical breaking of the weak interaction symmetries are reviewed. The expected signals include: (1) a rich spectrum of spinless pseudo‐Goldstone bosons, (2) flavor‐changing neutral‐current interactions mediating rare decays, and (3) an electric dipole moment for the neutron of approximately 10−24e cm.

ISSN:0094-243X    

DOI:10.1063/1.2947493

出版商:AIP    

年代:1980

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.2947498

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

I review recent progress (mostly theoretical) in our knowledge of photon‐photon interactions at high energies, concentrating on resonance production and on reactions which expose the pointlike coupling of photons to quarks: deep inelastic scattering on a photon or electron target and &ggr;&ggr;‐induced jet production at large transverse momentum.

ISSN:0094-243X    

DOI:10.1063/1.2947499

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The theory of the phenomenological QQinteraction, and of the hadron transitions between QQstates, is reviewed.

ISSN:0094-243X    

DOI:10.1063/1.2947500

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

A description of the CELLO detector at PETRA is given as well as first results showing the performance of the major components under beam conditions.

ISSN:0094-243X    

DOI:10.1063/1.2947482

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Results from the JADE experiment at PETRA in the energy range between 27.7 and 35.8 GeV are reported. QED is tested using the reactionse+e− ⇒ e+e−, &mgr;+&mgr;−, &ggr;&ggr;and lower limits on hypothetical cut‐off parameters of up to 100 GeV are obtained. Predictions of the standard electro‐weak theory are compared with the data and limits are derived on the values of the vector and axial vector coupling constants. Extended gauge models containing more than one neutral weak boson are also tested and lower limits are placed on the masses of such bosons.For the reactione+e− ⇒ hadronstopological distributions of the hadrons are studied. At s&sqrt; of about 30 GeV it is shown in a model independent way that the observed planar events actually possess three‐jet structure strongly suggesting gluon bremsstrahlung as the origin of these events. By comparison of the data with the qqg — model we obtain a value for the strong coupling constant of&agr;s (q2) = 0.17 ± 0.02 ± 0.05.At the highest energy of about 35 GeV a search for new flavour production is performed. An average value ofR = 3.9 ± 0.2is obtained, compatible with the production of quarks with only the known flavours (u, d, s, c, b). Also the study of the topological distribution of the final state hadrons at this energy shows no evidence for new flavour production.In the energy range between 12 and 35 GeV a measurement of the neutral energy fraction in multihadronic events is reported. Free quarks with chargeQ = 2/3are searched for and upper limits for the production have been derived from dE/dx measurements which are of the order of0.01· &sgr;&mgr;&mgr;. An upper limit of the lifetime of B‐mesons of about2 · 10−9sis obtained.

ISSN:0094-243X    

DOI:10.1063/1.2947483

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

We present data that establishes the validity of Q.E.D. to a distance< 2 × 10−16 cm. Relative cross sections and event distributions show that there is no new charge 2/3 quark pair production up tos&sqrt; = 35.8 GeV. We have discovered 3‐jet events; the rate of their production and their distributions agree with Q.C.D. predictions. We have measured the strong interaction coupling constant &agr;s.

ISSN:0094-243X    

DOI:10.1063/1.2947484

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The construction and performance of the detector are briefly described. Results are presented on QED reactions: bounds on cutoff parameters, weak‐electromagnetic interference, and properties of the &tgr; lepton. From hadronic events we have results on the search for the top quark, on inclusive distributions, on the identification of charged and neutral kaons and of baryons, and the yields and distributions of these particles. We have studied the properties of jets in 3 jet events, and have made a determination of the QCD coupling constant &agrsof0.17 ± 0.02 ± 0.03(at 30 GeV) independent of preconceived assumptions about the parameters of the jet fragmentation model.

ISSN:0094-243X    

DOI:10.1063/1.2947486

出版商:AIP    

年代:1980

数据来源: AIP