Isgur-Wise symmetry in two dimensions

Journal Article · Tue Dec 01 04:00:00 EST 1992 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.46.5083· OSTI ID:7030276

Burkardt, M; Swanson, E S ^[1]

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1. Center for Theoretical Physics, Laboratory for Nuclear Science, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

The approach to the heavy-quark Isgur-Wise limit is examined in (1+1)-dimensional QCD where exact calculations are possible. To facilitate the discussion, an explicit scaling equation for the mesonic Bethe-Salpeter amplitude is derived. We find that the leading finite heavy-quark mass corrections to the decay constant and the elastic form factor are comparable in strength. Nonrelativistic estimates of both of the quantities work reasonably well and generalize to 3+1 dimensions. We find that the corrections to the (3+1)-dimensional form factor at large {ital v}{center dot}{ital v}{prime} are comparable to those estimated for the decay constant by lattice gauge theory and QCD sum rules. Furthermore, the structure function {ital f}{sub {minus}}({ital v}{center dot}{ital v}{prime}) is found to be quite large at {ital v}{center dot}{ital v}{prime}=1 and we argue that this will remain true in 3+1 dimensions. This implies that one must exercise caution when attempting to extract Cabibbo-Kobayashi-Maskawa matrix elements from semileptonic decays. Finally, it is shown that the Isgur-Wise symmetry never breaks down in two-dimensional QCD for heavy-quark to heavy-quark transitions.

• DOE Contract Number: AC02-76ER03069
• OSTI ID: 7030276
• Journal Information: Physical Review, D (Particles Fields); (United States), Journal Name: Physical Review, D (Particles Fields); (United States) Vol. 46:11; ISSN PRVDA; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

662120 -- General Theory of Particles & Fields-- Symmetry
Conservation Laws
Currents & Their Properties-- (1992-)
662230* -- Quantum Chromodynamics-- (1992-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BETHE-SALPETER EQUATION
DECAY
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
FIELD THEORIES
FORM FACTORS
FOUR-DIMENSIONAL CALCULATIONS
FUNCTIONS
GAUGE INVARIANCE
INVARIANCE PRINCIPLES
KOBAYASHI-MASKAWA MATRIX
LATTICE FIELD THEORY
LIGHT CONE
MASS
MATRICES
MATRIX ELEMENTS
PARTICLE DECAY
PARTICLE PROPERTIES
POSTULATED PARTICLES
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARKS
SEMILEPTONIC DECAY
SPACE-TIME
STRUCTURE FUNCTIONS
SUM RULES
SYMMETRY
TWO-DIMENSIONAL CALCULATIONS
UNIFIED-FIELD THEORIES
WEAK PARTICLE DECAY
YANG-MILLS THEORY