Physics – High Energy Physics – High Energy Physics - Experiment
Scientific paper
2003-08-16
Phys.Rev.Lett.91:221802,2003
Physics
High Energy Physics
High Energy Physics - Experiment
7 pages, 2 postscript figues, submitted to Phys. Rev. Lett
Scientific paper
10.1103/PhysRevLett.91.221802
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 $\mu^+\mu^-$ 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 $123\times 10^6$ $\Upsilon(4S)\to B\bar{B}$ 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 $8\sigma$, while for $B\to K^*\ell^+\ell^-$ it is $3.3\sigma$.
No associations
LandOfFree
Evidence for the Rare Decay B -> K*ll and Measurement of the B -> Kll Branching Fraction does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Evidence for the Rare Decay B -> K*ll and Measurement of the B -> Kll Branching Fraction, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evidence for the Rare Decay B -> K*ll and Measurement of the B -> Kll Branching Fraction will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-44213