8-13 August 2011
Rhode Island Convention Center
US/Eastern timezone

Measurement of the production fraction times branching fraction f(b->Lambda_b)xB(Lambda_b -> J/psi Lambda)

12 Aug 2011, 16:00
554 (Rhode Island Convention Center)


Rhode Island Convention Center

Parallel contribution Heavy Flavor Physics (bottom, charm, tau) Heavy Flavor Physics


Ivan Heredia De La Cruz (Centro Invest. Estudios Avanz. IPN (CINVESTAV))


The $\Lambda_{b}(udb)$ baryon is observed in the decay $\Lambda_{b}\to J/\psi \Lambda$ using 6.1 fb$^{-1}$ of $p\bar{p}$ collisions collected with the D0 detector at $\sqrt{s}=1.96$ TeV. The production fraction multiplied by the branching fraction for this decay relative to that for the decay $B^{0}\to J/\psi K^{0}_{s}$ is measured to be $0.345 \pm 0.034 \mbox{ (stat.)} \pm 0.033\mbox{ (syst.)} \pm 0.003\mbox{ (PDG)}$. Using the world average value of $f(b\to B^{0})\cdot\mathcal{B}(B^{0}\to J/\psi K^{0}_{s})=(1.74\pm 0.08)\times 10^{-5}$, we obtain $f(b\to\Lambda_{b})\cdot \mathcal{B} \left( \Lambda_{b} \rightarrow J/\psi \Lambda \right) = (6.01\pm 0.60\mbox{ (stat.)}\pm0.58\mbox{ (syst.)} \pm 0.28 \mbox{ (PDG)})\times 10^{-5}$. This measurement represents an improvement in precision by about a factor of three with respect to the current world average.

Primary author

Ivan Heredia De La Cruz (Centro Invest. Estudios Avanz. IPN (CINVESTAV))

Presentation Materials