Challenges to quantum chromodynamics: Anomalous spin, heavy quark, and nuclear phenomena
The general structure of QCD meshes remarkably well with the facts of the hadronic world, especially quark-based spectroscopy, current algebra, the approximate point-like structure of large momentum transfer inclusive reactions, and the logarithmic violation of scale invariance in deep inelastic lepton-hadron reactions. QCD has been successful in predicting the features of electron-positron and photon-photon annihilation into hadrons, including the magnitude and scaling of the cross sections, the shape of the photon structure function, the production of hadronic jets with patterns conforming to elementary quark and gluon subprocesses. The experimental measurements appear to be consistent with basic postulates of QCD, that the charge and weak currents within hadrons are carried by fractionally-charged quarks, and that the strength of the interactions between the quarks, and gluons becomes weak at short distances, consistent with asymptotic freedom. Nevertheless in some cases, the predictions of QCD appear to be in dramatic conflict with experiment. The anomalies suggest that the proton itself as a much more complex object than suggested by simple non-relativistic quark models. Recent analyses of the proton distribution amplitude using QCD sum rules points to highly-nontrival proton structure. Solutions to QCD in one-space and one-time dimension suggest that the momentum distributions of non-valence quarks in the hadrons have a non-trival oscillatory structure. The data seems also to be suggesting that the intrinsic'' bound state structure of the proton has a non- negligible strange and charm quark content, in addition to the extrinsic'' sources of heavy quarks created in the collision itself. 144 refs., 46 figs., 2 tabs.
- Research Organization:
- Stanford Linear Accelerator Center, Menlo Park, CA (USA)
- Sponsoring Organization:
- DOE/ER
- DOE Contract Number:
- AC03-76SF00515
- OSTI ID:
- 5075028
- Report Number(s):
- SLAC-PUB-5116; CONF-8907177-2; ON: DE90005799; TRN: 90-005070
- Resource Relation:
- Conference: Ettore Majorana international school of subnuclear physics, Erice (Italy), 26 Jul - 3 Aug 1989
- Country of Publication:
- United States
- Language:
- English
Similar Records
Polarization phenomena in quantum chromodynamics
Novel High Transverse Momentum Phenomena in Hadronic and Nuclear Collisions
Related Subjects
QUANTUM CHROMODYNAMICS
EVALUATION
BOUND STATE
BRANCHING RATIO
CHARMONIUM
CROSS SECTIONS
DEEP INELASTIC SCATTERING
FACTORIZATION
FINAL-STATE INTERACTIONS
FORM FACTORS
J PSI-3097 MESONS
LAGRANGIAN FUNCTION
LIGHT CONE
NUCLEAR REACTIONS
NUCLEAR STRUCTURE
PARTICLE PRODUCTION
PROTON-PROTON INTERACTIONS
PROTONS
QUARKONIUM
QUARKS
STRUCTURE FUNCTIONS
TAU PARTICLES
WAVE FUNCTIONS
BARYON-BARYON INTERACTIONS
BARYONS
BOSONS
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
FUNCTIONS
HADRON-HADRON INTERACTIONS
HADRONS
HEAVY LEPTONS
INELASTIC SCATTERING
INTERACTIONS
LEPTON-BARYON INTERACTIONS
LEPTON-HADRON INTERACTIONS
LEPTON-NUCLEON INTERACTIONS
LEPTONS
MESONS
NUCLEON-NUCLEON INTERACTIONS
NUCLEONS
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
POSTULATED PARTICLES
PROTON-NUCLEON INTERACTIONS
QUANTUM FIELD THEORY
SCATTERING
SPACE-TIME
VECTOR MESONS
645200* - High Energy Physics- Particle Interactions & Properties-Theoretical