Evidence for the Rare Decay B -> K*ll and Measurement of the B -> Kll Branching Fraction
| dc.creator | Aubert, B. | |
| dc.date | 2003-08-16 | |
| dc.date.accessioned | 2026-07-07T12:02:04Z | |
| dc.date.available | 2026-07-07T12:02:04Z | |
| dc.description | We present evidence for the flavor-changing neutral current decay $B\to K^*\ell^+\ell^-$ and a measurement of the branching fraction for the related process $B\to K\ell^+\ell^-$, where $\ell^+\ell^-$ is either an $e^+e^-$ or $μ^+μ^-$ pair. These decays are highly suppressed in the Standard Model, and they are sensitive to contributions from new particles in the intermediate state. The data sample comprises $123\times 10^6$ $Υ(4S)\to B\bar{B}$ decays collected with the Babar detector at the PEP-II $e^+e^-$ storage ring. Averaging over $K^{(*)}$ isospin and lepton flavor, we obtain the branching fractions ${\mathcal B}(B\to K\ell^+\ell^-)=(0.65^{+0.14}_{-0.13}\pm 0.04)\times 10^{-6}$ and ${\mathcal B}(B\to K^*\ell^+\ell^-)=(0.88^{+0.33}_{-0.29}\pm 0.10)\times 10^{-6}$, where the uncertainties are statistical and systematic, respectively. The significance of the $B\to K\ell^+\ell^-$ signal is over $8σ$, while for $B\to K^*\ell^+\ell^-$ it is $3.3σ$. | |
| dc.description | 7 pages, 2 postscript figues, submitted to Phys. Rev. Lett | |
| dc.identifier | https://arxiv.org/abs/hep-ex/0308042 | |
| dc.identifier | http://arxiv.org/abs/hep-ex/0308042 | |
| dc.identifier | Phys.Rev.Lett.91:221802,2003 | |
| dc.identifier | doi:10.1103/PhysRevLett.91.221802 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/207311 | |
| dc.subject | High Energy Physics - Experiment | |
| dc.title | Evidence for the Rare Decay B -> K*ll and Measurement of the B -> Kll Branching Fraction | |
| dc.type | text |