Unitarity constraints on the {ital B} and {ital B}{sup {asterisk}} form factors from QCD analyticity and heavy quark spin symmetry
- Institute for Atomic Physics, P.O. Box MG 6, R-76900 Bucharest (Romania)
A method of deriving bounds on the weak meson form factors, based on perturbative QCD, analyticity, and unitarity, is generalized in order to fully exploit heavy quark spin symmetry in the ground state ({ital L}=0) doublet of pseudoscalar ({ital B}) and vector ({ital B}{sup {asterisk}}) mesons. All the relevant form factors of these mesons are taken into account in the unitarity sum. They are treated as independent functions along the timelike axis, being related by spin symmetry only near the zero recoil point. Heavy quark vacuum polarization up to three loops in perturbative QCD and the experimental cross sections {sigma}({ital e}{sup +}{ital e}{sup {minus}}{r_arrow}{Upsilon}) are used as input. We obtain bounds on the charge radius of the elastic form factor of the {ital B} meson, which considerably improve previous results derived in the same framework. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 388946
- Journal Information:
- Physical Review, D, Vol. 54, Issue 9; Other Information: PBD: Nov 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Improved unitarity bounds on the {ital B}-meson form factors from heavy quark spin symmetry
Perturbative QCD study of {ital B}{r_arrow}{ital D}{sup ({asterisk})} decays