Study of the kinematic dependences of $\hat{I}{›}_b^0$ production in $pp$ collisions and a measurement of the $\hat{I}{›}_b^0\to \hat{I}{›}_c^{+}\ddot{I}{€}^{-}$ branching fraction

Abstract

The kinematic dependences of the relative production rates, $f_{\hat{I}{›}_b^0}/f_d$, of $\hat{I}{›}_b^0$ baryons and ${\bar{B}}^0$ mesons are measured using $\hat{I}{›}_b^0\to \hat{I}{›}_c^{+}\ddot{I}{€}^{-}$ and ${\bar{B}}^0\to D^{+}\ddot{I}{€}^{-}$ decays. The measurements use proton-proton collision data, corresponding to an integrated luminosity of 1 fb${}^{-1}$ at a centre-of-mass energy of 7 TeV, recorded in the forward region with the LHCb experiment. The relative production rates are observed to depend on the transverse momentum, $p_T$, and pseudorapidity, $\hat{I}\cdot$, of the beauty hadron, in the studied kinematic region $1.5<p_T<40$ GeV/$c$ and $2<\hat{I}\cdot <5$. Using a previous LHCb measurement of $f_{\hat{I}{›}_b^0}/f_d$ in semileptonic decays, the branching fraction $\mathcal{B}(\hat{I}{›}_b^0\to \hat{I}{›}_c^{+}\ddot{I}{€}^{-})=(4.30\pm 0.03{}_{-0.11}^{+0.12}\pm 0.26\pm 0.21)\times 10^{-3}$ is obtained, where the first uncertainty is statistical, the second is systematic, the third is from the previous LHCb measurement of $f_{\hat{I}{›}_b^0}/f_d$ and the fourth is due to the ${\bar{B}}^0\to D^{+}\ddot{I}{€}^{-}$ branching fraction. This is the most precise measurement of a $\hat{I}{›}_b^0$ branching fraction to date.

v2 as published