Determining. Gamma. (b yields ul. nu. )/. Gamma. (b yields cl. nu. ) from the end-point region of the lepton momentum spectrum in B-meson decay

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5093637

Guida, J A

An upper limit is placed on {Gamma}(b {yields} ul{nu})/{Gamma}(b {yields} cl{nu}) from lepton production in the end-point region of the lepton momentum spectrum in semileptonic B-meson decay. The B mesons are produced at the {Upsilon}(4S) resonance from e{sup +}e{sup {minus}} annihilations at the Cornell Electron Storage Ring (CESR). The CLEO detector is used to study B-meson semileptonic decay processes. Methods of reducing the continuum background are employed to determine the lepton contribution from B mesons at the upper end of the momentum spectrum. The method of find {Gamma} (b {yields} ul{nu})/{Gamma}(B {yields} cl{nu}) has only a small dependence upon the b {yields} cl{nu} model and can be expressed explicitly in terms of the b {yields} ul{nu} model. If f{sub u}(2.3) is the fraction of leptons from b {yields} ul{nu} in the momentum range from 2.3-2.6 GeV/c, then {Gamma}(b{yields}ul{nu})/{Gamma}b{yields}cl{nu} = (0.000 {plus minus} 0.011) (0.115/f{sub u}(2.3)-0.002). For the various b {yields} ul{nu}models considered here, f{sub u} (2.3) ranges from 0.0750 to 0.1584, corresponding to 90% confidence level upper limits for {Gamma} (b {yields} ul{nu})/{Gamma}(b {yields} cl{nu}) between 0.027 and 0.013. These limits are converted into limits on the ratio of the Kobayashi-Maskawa matrix elements V{sub ub} and V{sub cb} and are found to range from 0.08 to 0.15. The implications of these limits on the standard model are discussed.

• Research Organization: Rochester Univ., NY (USA)
• OSTI ID: 5093637
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400101 -- Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures
645100* -- High Energy Physics-- Particle Interactions & Properties-Experimental
651100 -- Nuclear Physics-- Experimental Techniques-- (1980-)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
B MESONS
BOSONS
CALCULATION METHODS
CESR STORAGE RING
DATA
ELEMENTARY PARTICLES
EXPERIMENTAL DATA
FERMIONS
HADRONS
INFORMATION
LEPTONS
MEASURING INSTRUMENTS
MEASURING METHODS
MESONS
NUMERICAL DATA
PRODUCTION
PSEUDOSCALAR MESONS
STORAGE RINGS