Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9861040 | Physics Letters B | 2005 | 13 Pages |
Abstract
We report measurements of partial branching fractions of inclusive charmless semileptonic B-meson decays at the endpoint of the electron momentum spectrum. The measurements are made in six overlapping momentum intervals that have lower bounds ranging from 1.9 to 2.4 GeV/c and a common upper bound of 2.6 GeV/c, as measured in the centre of mass frame. The results are based on a sample of 29 million BB¯ pairs, accumulated by the Belle detector at the KEKB asymmetric e+eâ collider operating on the Ï(4S) resonance. In the momentum interval ranging from 1.9 to 2.6 GeV/c we measure the partial branching fraction ÎB(BâXueνe)=(8.47±0.37±1.53)Ã10â4, where the first error is statistical and the second is systematic. A prediction of the partial rate R=(21.69±3.62â1.98+2.18)|Vub|2psâ1 in this momentum interval based on theory is calculated with input HQET parameters that have been derived from Belle's measurement of the BâXsγ photon energy spectrum, where the first error is due to the uncertainty on HQET parameters and the second error is from theory. Using both ÎB(BâXueνe) and R we find |Vub|=(5.08±0.47±0.42â0.23+0.26)Ã10â3, where the first error is from the partial branching fraction, and the second and third errors are from uncertainties in R.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Nuclear and High Energy Physics
Authors
Belle Collaboration Belle Collaboration, A. Limosani, K. Abe, K. Abe, I. Adachi, H. Aihara, Y. Asano, T. Aushev, S. Bahinipati, A.M. Bakich, E. Barberio, U. Bitenc, I. Bizjak, S. Blyth, A. Bondar, A. Bozek, M. BraÄko, J. Brodzicka, D. Žontar,