Search for a Structure in the ${B}_{s}^{0}{\pi }^{±}$ Invariant Mass Spectrum with the ATLAS Experiment

A search for the narrow structure, $X\left(5568\right)$, reported by the D0 Collaboration in the decay sequence $X\to {B}_{s}^{0}{\pi }^{±}$, ${B}_{s}^{0}\to J/\psi \varphi $, is presented. The analysis is based on a data sample recorded with the ATLAS detector at the LHC corresponding to $4.9\text{}\text{}{\mathrm{fb}}^{-1}$ of $pp$ collisions at 7 TeV and $19.5\text{}\text{}{\mathrm{fb}}^{-1}$ at 8 TeV. No significant signal was found. Upper limits on the number of signal events, with properties corresponding to those reported by D0, and on the $X$ production rate relative to ${B}_{s}^{0}$ mesons, ${\rho }_{X}$, were determined at 95% confidence level. The results are $N\left(X\right)<382$ and ${\rho }_{X}<0.015$ for ${B}_{s}^{0}$ mesons with transverse momenta above 10 GeV, and $N\left(X\right)<356$ and ${\rho }_{X}<0.016$ for transverse momenta above 15 GeV. Limits are also set for potential ${B}_{s}^{0}{\pi }^{±}$ resonances in the mass range 5550 to 5700 MeV.