Evidence for a new structure in the $J/\ddot{I}ˆp$ and $J/\ddot{I}ˆ\bar{p}$ systems in $B_s^0\to J/\ddot{I}ˆp\bar{p}$ decays

Abstract

An amplitude analysis of flavour-untagged $B_s^0\to J/\ddot{I}ˆp\bar{p}$ decays is performed using a sample of $797\pm 31$ decays reconstructed with the LHCb detector. The data, collected in proton-proton collisions between 2011 and 2018, correspond to an integrated luminosity of 9 ${\text{fb}}^{-1}$. Evidence for a new structure in the $J/\ddot{I}ˆp$ and $J/\ddot{I}ˆ\bar{p}$ systems with a mass of $4337{}_{-4}^{+7}{}_{-2}^{+2}\text{MeV}$ and a width of $29{}_{-12}^{+26}{}_{-14}^{+14}\text{MeV}$ is found, where the first uncertainty is statistical and the second systematic, with a significance in the range of 3.1 to 3.7 $\ddot{I}ƒ$, depending on the assigned $J^P$ hypothesis.

All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2021-018.html (LHCb public pages)