Observation of muonic Dalitz decays of ${\chi }_b$ mesons and precise spectroscopy of hidden-beauty states

Abstract

The decays of the ${\chi }_{b1}(1P)$, ${\chi }_{b2}(1P)$, ${\chi }_{b1}(2P)$ and ${\chi }_{b2}(2P)$ mesons into the ${\rm Y}(1S){\mu }^{+}{\mu }^{-}$ final state are observed with a high significance using proton-proton collision data collected with the LHCb detector and corresponding to an integrated luminosity of 9fb${}^{-1}$. The newly observed decays together with the ${\rm Y}(2S)\to {\rm Y}(1S){\pi }^{+}{\pi }^{-}$ and ${\rm Y}(3S)\to {\rm Y}(2S){\pi }^{+}{\pi }^{-}$ decay modes are used for precision measurements of the mass and mass splittings for the hidden-beauty states.

All figures and tables, along with any supplementary material and additional information, are available at https://lbfence.cern.ch/alcm/public/analysis/full-details/3633

References in corpus (6)

• Heavy quarkonium: progress, puzzles, and opportunities
• Charmonium
• 50 Years of Quantum Chromodynamics
• RapidSim: an application for the fast simulation of heavy-quark hadron decays
• Two-pion transitions in quarkonium revisited
• Revision of results on ${\rm Y}(1S)$, ${\rm Y}(2S)$, and ${\rm Y}(3S)$ masses

Cited by in corpus (1)

• Observation of the decay ${\chi }_{c1}(3872)\to J/\psi {\mu }^{+}{\mu }^{-}$