Some recent developments in the recombination model

Conference · Mon Jan 01 04:00:00 EST 1979

OSTI ID:5641734

Hwa, R C

A critical review of the recombination model for hadron production at low P/sub T/ is first given, emphasizing not so much the successes as unanswered questions that the model faces. A systematic program to answer some of the basic questions is then developed. The theoretical framework is quantum chromodynamics. First, in what may appear as a digression, the possibility of formation of valence quark clusters (called valons) in a nucleon due to gluon bremsstrahlung and quark-pair creation is considered. Evidences are found not only for the valons in neutrino scattering data, but also indications for their momentum distribution in a nucleon. When similar considerations are applied to a meson, the meaning of the recombination function is discussed and its normalization as well as its shape are determined. Next, the problem of quark decay in a hard scattering process (e.g., pion production in e/sup +/e/sup -/ annihilation) is considered. The joint distribution of partons in a quark jet is determined in QCD. The quark decay function for pions in the recombination model is then obtained with excellent fit to the data. Similar investigation is applied to the problem of photoproduction of pions in the fragmentation region; again good agreement with data is achieved. The results indicate the reliability of the recombination model when the two-parton distributions can be calculated in QCD. Finally, hadron initiated reactions are considered. A duality between quark recombination and valon fragmentation is suggested. The picture is consistent with dual Regge model. A possible way to determine the inclusive distribution in the context of QCD is suggested.

• Research Organization: Oregon Univ., Eugene (USA). Inst. of Theoretical Science
• OSTI ID: 5641734
• Report Number(s): DOE/ER/70004-232; RLO-2230-T4-232; CONF-7905142-1
• Country of Publication: United States
• Language: English

Related Subjects

645204* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Strong Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BASIC INTERACTIONS
COMPOSITE MODELS
DECAY
ELEMENTARY PARTICLES
FIELD THEORIES
HADRON REACTIONS
HADRONS
INTERACTIONS
JET MODEL
MATHEMATICAL MODELS
NUCLEAR REACTIONS
PARTICLE DECAY
PARTICLE MODELS
PARTON MODEL
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
RECOMBINATION
STRONG INTERACTIONS