Relativistic effects in proton-antiproton annihilation into two mesons

Journal Article · Wed Aug 01 04:00:00 EDT 1990 · Physical Review, C (Nuclear Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevC.42.716· OSTI ID:6606397

Maruyama, M; Gutsche, T; Faessler, A; Strobel, G L ^[1]

---

1. Institut fuer Theoretische Physik, Universitaet Tuebingen, Auf der Morgenstelle 14, 7400 Tuebingen (Federal Republic of Germany)

The effects of the small components of Dirac spinors, used to describe quark and antiquark wave functions in clusters, and the Lorentz contraction of cluster wave functions associated with the Lorentz transformation to the overall center of momentum frame are considered in the proton-antiproton annihilation into two final state mesons. A quark-antiquark pair annihilation and creation model in the planar picture that reproduces the principly observed final states in the nonrelativistic case is used. The effects are studied by taking the nonrelativistic model as a base of comparison. The introduction of small components in the quark wave functions has little influence on predictions of relative ratios of annihilation amplitudes into final state mesons in the same relative angular momentum state of the initial proton and antiproton. In contrast, the small components give a large contribution to the absolute value of the annihilation amplitude in dependence on the initial relative angular momentum. The effects of including the Lorentz contraction of the cluster wave functions appear in the annihilation amplitudes of two meson final states. By using Lorentz transformed Gaussian wave functions for the clusters, subsequent effects on the annihilation amplitudes into two mesons, such as {pi}{pi}, {rho}{pi}, and {rho}{rho}, are studied. For a nucleon radius of {l angle}{ital r}{sup 2}{r angle}{sub {ital N}}{sup 1/2}=0.62 fm and a global meson radius of {l angle}{ital r}{sup 2}{r angle}{sub {ital M}}{sup 1/2}=0.50 fm, the production of two final state pions is enhanced upon including the Lorentz contraction effects.

• OSTI ID: 6606397
• Journal Information: Physical Review, C (Nuclear Physics); (USA), Journal Name: Physical Review, C (Nuclear Physics); (USA) Vol. 42:2; ISSN 0556-2813; ISSN PRVCA
• 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
ANNIHILATION
BARYON-BARYON INTERACTIONS
BASIC INTERACTIONS
BOSONS
CLUSTER MODEL
COMPOSITE MODELS
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
FUNCTIONS
HADRON-HADRON INTERACTIONS
HADRONS
INTERACTIONS
LORENTZ TRANSFORMATIONS
MATHEMATICAL MODELS
MESONS
NUCLEAR MODELS
NUCLEON-ANTINUCLEON INTERACTIONS
PARTICLE INTERACTIONS
PARTICLE MODELS
PROTON-ANTIPROTON INTERACTIONS
QUARK MODEL
TRANSFORMATIONS
WAVE FUNCTIONS