Search for the Rare Decays B_{s}^{0}→e^{+}e^{-} and B^{0}→e^{+}e^{-}.

Area of Science:

• High Energy Physics
• Particle Physics
• Standard Model Physics

Background:

• Rare B meson decays provide sensitive probes of new physics beyond the Standard Model.
• Previous searches for B_{s}^{0}→e^{+}e^{-} and B^{0}→e^{+}e^{-} decays had less stringent limits.

Purpose of the Study:

• To search for the rare decays B_{s}^{0}→e^{+}e^{-} and B^{0}→e^{+}e^{-}.
• To set new upper limits on the branching fractions of these decays.
• To constrain new physics models.

Main Methods:

• Utilized proton-proton collision data collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV.
• Analyzed integrated luminosities of 1, 2, and 2 fb^{-1} for the respective energy datasets.
• Performed a signal-blinded search to establish upper limits on branching fractions.

Main Results:

• No statistically significant signal was observed for either B_{s}^{0}→e^{+}e^{-} or B^{0}→e^{+}e^{-} decays.
• An upper limit on the branching fraction B(B_{s}^{0}→e^{+}e^{-})<9.4(11.2)×10^{-9} was set at 90%(95%) confidence level.
• An upper limit on the branching fraction B(B^{0}→e^{+}e^{-})<2.5(3.0)×10^{-9} was set at 90%(95%) confidence level.

Conclusions:

• The obtained upper limits are more than an order of magnitude lower than previous experimental results.
• These stringent limits place significant constraints on theoretical models predicting such rare decays.
• The results contribute to the ongoing search for physics beyond the Standard Model.