$\Upsilon$-meson pair production at LHC
  Theoretical predictions for $pp\to 2 \Upsilon+X$ cross section at $\sqrt{s}=8$ TeV for the LHCb and ATLAS kinematical conditions are obtained. A possibility to observe the new hypothetical particles containing two valence $b$-quarks and two valence $\bar{b}$-quarks is discussed. 
A. V. Berezhnoy, A. K. Likhoded and A. A. Novoselov
hep-ph