Search for a Structure in the B_{s}^{0}π^{±} Invariant Mass Spectrum with the ATLAS Experiment

Area of Science:

• High Energy Physics
• Particle Physics
• Hadron Spectroscopy

Background:

• The D0 Collaboration reported evidence for a narrow structure, X(5568), in the decay sequence X→B_{s}^{0}π^{±}, with B_{s}^{0}→J/ψϕ.
• The existence and properties of exotic hadrons are of significant interest in understanding the strong interaction.

Purpose of the Study:

• To independently search for the reported X(5568) structure using ATLAS data.
• To set limits on the production rate and event yield of the X(5568) if it exists with the reported properties.

Main Methods:

• Analysis of proton-proton collision data collected by the ATLAS detector at the Large Hadron Collider (LHC).
• Data samples correspond to integrated luminosities of 4.9 fb⁻¹ at 7 TeV and 19.5 fb⁻¹ at 8 TeV.
• Searched for the decay X→B_{s}^{0}π^{±} and set upper limits at 95% confidence level.

Main Results:

• No significant signal for the X(5568) structure was observed.
• Upper limits were determined for the number of signal events (N(X)) and the production rate relative to B_{s}^{0} mesons (ρ_{X}).
• Specific limits include N(X)<382 and ρ_{X}<0.015 for pT(B_{s}^{0})>10 GeV, and N(X)<356 and ρ_{X}<0.016 for pT(B_{s}^{0})>15 GeV.

Conclusions:

• The ATLAS results do not confirm the observation of the X(5568) structure reported by D0.
• The derived upper limits provide constraints on the existence of such a particle in the studied decay channels and mass range.
• Further studies in other decay modes or with increased integrated luminosity may be needed to fully explore the possibility of exotic states in this mass region.