Search for a dark photon in e(+)e(-) collisions at BABAR

Area of Science:

• Particle Physics
• Cosmology
• Dark Matter Physics

Background:

• Dark sectors and dark matter models propose new Abelian interactions.
• A light mediator, the dark photon, could connect the dark sector to the Standard Model.
• The anomalous magnetic moment of the muon shows a discrepancy, potentially explained by new physics.

Purpose of the Study:

• To search for a dark photon in electron-positron collisions.
• To set limits on the dark photon's properties and its interaction strength with the Standard Model.
• To constrain parameter spaces relevant to dark matter and muon anomalous magnetic moment anomalies.

Main Methods:

• Analysis of 514 fb^{-1} of data collected by the BABAR detector.
• Searched for the dark photon via the e^{+}e^{-}→γA^{'}, A^{'}→e^{+}e^{-}, μ^{+}μ^{-} reaction.
• Statistical analysis to compare observed data with Standard Model predictions.

Main Results:

• No statistically significant deviation from Standard Model predictions was observed.
• 90% confidence level upper limits on the photon-dark photon mixing strength were set between 10^{-4} and 10^{-3}.
• Limits were placed on dark photon masses from 0.02 to 10.2 GeV.

Conclusions:

• The search for a dark photon yielded no significant signal.
• The results constrain dark matter models featuring a dark photon mediator.
• This study provides constraints relevant to the muon anomalous magnetic moment puzzle.