Exclusive and inclusive semileptonic decays of the B meson

Thesis/Dissertation · Sat Dec 31 23:00:00 EST 1988

OSTI ID:6044765

Bortoletto, D

Using data collected with the CLEO detector at the Cornell Electron Storage Ring (CESR) the author has performed a study of semileptonic B decay. This provides information on the Kobayashi-Maskawa matrix element V{sub cb} that is a free parameter of the Standard Model. Understanding of b {yields} c semileptonic decays can discriminate between various Phenomenological models Providing insight into the understanding of b {yields} u transition. He observes 109 events consistent with {anti B}{sup o} {yields} D*{sup +} {ell}{sup {minus}}{anti {mu}} and he measures the branching fraction B({anti B} {yields} D*{sup +} {ell}{sup {minus}}{anti {mu}}) to be (4.6 {plus minus} 0.5 {plus minus} 1.1)% which yields a value of V{sub cb} around 0.040 in the framework of the form factor models. He has also measured the polarization of the D*{sup +} meson in this decay to be: a = 0.65 {plus minus} 0.66 {plus minus} 0.25 for lepton momentum >1.4 GeV/c. He has studied the behavior of other kinematical variables and the results are in agreement with theoretical models. He measures B(B {yields} D**{ell}{nu} + B {yields} D*{pi}{ell}{nu}) = (1.8 {plus minus} 0.9 {plus minus} 0.7)%. He also exploits the capability of the {anti B}{sup 0}{yields} D*{sup +}{ell}{sup {minus}}{anti {nu}} as a tag for neutral B mesons. He measures the neutral B meson semileptonic branching ratio to be B({anti B}{sup 0}{yields}X{sup +}{ell}{sup {minus}}{anti {nu}}) = (10.5 {plus minus} 3.3 {plus minus} 0.7)% and the mixing parameter r = 0.23 {plus minus} 0.10 {plus minus} 0.08.

• Research Organization: Syracuse Univ., NY (USA)
• OSTI ID: 6044765
• Country of Publication: United States
• Language: English

Related Subjects

645102* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Weak Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANTI-B NEUTRAL MESONS
B MESONS
B NEUTRAL MESONS
BOSONS
BRANCHING RATIO
CESR STORAGE RING
DECAY
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
HADRONS
KOBAYASHI-MASKAWA MATRIX
MATRICES
MESONS
MIXING RATIO
PARTICLE DECAY
POSTULATED PARTICLES
PSEUDOSCALAR MESONS
QUARKS
SEMILEPTONIC DECAY
STORAGE RINGS
UNIFIED-FIELD THEORIES
WEAK PARTICLE DECAY