Study of $\ddot{I}{‡}_b$ meson production in pp collisions at $\sqrt{s}=7$ and 8TeV and observation of the decay $\ddot{I}{‡}_b\to \hat{I}\yen (3S){\hat{I}}^3$

Abstract

A study of $\ddot{I}{‡}_b$ meson production at LHCb is performed on proton-proton collision data, corresponding to 3.0fb${}^{-1}$ of integrated luminosity collected at centre-of-mass energies $\sqrt{s}=7$ and 8TeV. The fraction of $\hat{I}\yen (nS)$ mesons originating from $\ddot{I}{‡}_b$ decays is measured as a function of the $\hat{I}\yen$ transverse momentum in the rapidity range $2.0<y^{\hat{I}}\yen <4.5$. The radiative transition of the $\ddot{I}{‡}_b(3P)$ meson to $\hat{I}\yen (3S)$ is observed for the first time. The $\ddot{I}{‡}_{b1}(3P)$ mass is determined to be $$m(\ddot{I}{‡}_{b1}(3P))=10511.3\pm 1.7\pm 2.5MeV/c^2,$$ where the first uncertainty is statistical and the second is systematic.

22 pages, 3 fugurs