Measurement of the B0 to pi l nu and B+ to pi0 l nu Branching Fractions and Determination of |Vub| in Upsilon(4S) to BBbar Events Tagged by a Fully Reconstructed B Meson

Conference · Fri Aug 26 00:00:00 EDT 2005

OSTI ID:878731

Aubert, B; Barate, R; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Pappagallo, M; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I

The authors report preliminary measurements of the charmless exclusive semileptonic branching fractions of the B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu} and B{sup +} {yields} {pi}{sup 0}{ell}{sup +}{nu} decays, based on 211 fb{sup -1} of data collected at the {Upsilon}(4S) resonance by the BABAR detector. In events in which the decay of one B meson to a hadronic final state is fully reconstructed, the semileptonic decay of the second B meson is identified by the detection of a charged lepton and a pion. They measure the partial branching fractions for B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu} and B{sup +} {yields} {pi}{sup 0}{ell}{sup +}{nu} in three regions of the invariant mass squared of the lepton pair, and they obtain the total branching fractions {Beta}(B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu}) = (1.14 {+-} 0.27{sub stat} {+-} 0.17{sub syst}) x 10{sup -4} and {Beta}(B{sup +} {yields} {pi}{sup 0}{ell}{sup +}{nu}) = (0.86 {+-} 0.22{sub stat} {+-} 0.11{sub syst}) x 10{sup -4}. Using isospin symmetry, they measure the combined total branching fraction {Beta}(B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu}) = (1.28 {+-} 0.23{sub stat} {+-} 0.16{sub syst}) x 10{sup -4}. Theoretical predictions of the form-factor are used to determine the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub ub}| = (3.7 {+-} 0.3{sub stat} {+-} 0.2{sub syst{sub -0.5FF}{sup +0.8}}) x 10{sup -3}, where the last uncertainty is due to the form-factor normalization.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 878731
• Report Number(s): SLAC-PUB-11369; hep-ex/0507085; TRN: US0602463
• Resource Relation: Conference: Presented at EPS International Europhysics Conference on High Energy Physics (HEP-EPS 2005), Lisbon, Portugal, 21-27 Jul 2005
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
B MESONS
DECAY
DETECTION
HIGH ENERGY PHYSICS
ISOSPIN
LEPTONS
MATRIX ELEMENTS
RESONANCE
SEMILEPTONIC DECAY
SYMMETRY
Experiment-HEP
HEPEX
HEPPH