Search for New Physics in Electronic Recoil Data from XENONnT

Area of Science:

• Particle Physics
• Cosmology
• Astrophysics

Background:

• The search for dark matter is a major focus in modern physics.
• Previous experiments like XENON1T have provided valuable data but faced background challenges.
• Understanding low-energy electronic recoils is crucial for distinguishing potential dark matter signals from background events.

Purpose of the Study:

• To analyze low-energy electronic recoil data from the XENONnT dark matter experiment's first science run.
• To establish new, stringent limits on hypothetical particles like solar axions, enhanced neutrino magnetic moments, and bosonic dark matter.
• To demonstrate the improved background reduction capabilities of the XENONnT detector.

Main Methods:

• A blinded analysis of data from the XENONnT detector.
• Utilizing a 5.9-ton liquid xenon target and novel subsystems to minimize background noise.
• Collecting 1.16 ton-years of exposure data for analysis.

Main Results:

• Achieved a background level of (15.8±1.3) events/(ton×year×keV) in the (1, 30) keV search region, the lowest ever for a dark matter detector.
• Observed no significant excess of events above the expected background.
• Established new, stringent limits on solar axions, neutrino magnetic moments, and bosonic dark matter.

Conclusions:

• The XENONnT experiment has successfully reduced background levels significantly compared to previous experiments.
• The data collected sets world-leading constraints on several beyond-Standard-Model physics scenarios.
• The detector's performance indicates its suitability for future, more sensitive dark matter searches.