Search for New Physics in Electronic Recoil Data from XENONnT

Physical Review Letters · 2022 · 279 citations

• Physics
• Nuclear physics
• Particle physics

We report on a blinded analysis of low-energy electronic recoil data from the first science run of the XENONnT dark matter experiment. Novel subsystems and the increased 5.9 ton liquid xenon target reduced the background in the (1, 30) keV search region to (15.8±1.3) events/(ton×year×keV), the lowest ever achieved in a dark matter detector and ∼5 times lower than in XENON1T. With an exposure of 1.16 ton-years, we observe no excess above background and set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter.

Measurement of the anomalous precession frequency of the muon in the Fermilab Muon<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>g</mml:mi><mml:mo>−</mml:mo><mml:mn>2</mml:mn></mml:math>Experiment

Physical review. D/Physical review. D. · 2021 · 196 citations

• Physics
• Nuclear physics
• Particle physics

The Muon g -2 Experiment at Fermi National Accelerator Laboratory (FNAL) has measured the muon anomalous precession frequency m a to an uncertainty of 434 parts per billion (ppb), statistical, and 56 ppb, systematic, with data collected in four storage ring configurations during its first physics run in 2018. When combined with a precision measurement of the magnetic field of the experiment's muon storage ring, the precession frequency measurement determines a muon magnetic anomaly of a FNAL 116 592 04054 10 -11 (0.46 ppm). This article describes the multiple techniques employed in the reconstruction, analysis, and fitting of the data to measure the precession frequency. It also presents the averaging of the results from the 11 separate determinations of m a , and the systematic uncertainties on the result.

A possible planet candidate in an external galaxy detected through X-ray transit

Nature Astronomy · 2021 · 18 citations

• Physics
• Astrophysics
• Astronomy

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm

Physical Review Letters · 2021 · 1322 citations

• Physics
• Condensed matter physics
• Nuclear physics

We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g -2 Experiment for the positive muon magnetic anomaly a g -2=2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency a between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency 0

Excess electronic recoil events in XENON1T

Physical review. D/Physical review. D. · 2020 · 493 citations

• Physics
• Nuclear physics

We report results from searches for new physics with low-energy electronic recoil data recorded with the XENON1T detector. With an exposure of 0.65 tonne-years and an unprecedentedly low background rate of 76 AE 2 stat events=tonne year keV between 1 and 30 keV, the data enable one of the most sensitive searches for solar axions, an enhanced neutrino magnetic moment using solar neutrinos, and bosonic dark matter. An excess over known backgrounds is observed at low energies and most prominent between 2 and 3 keV. The solar axion model has a 3.4 significance, and a three-dimensional 90% confidence surface is reported for axion couplings to electrons, photons, and nucleons. This surface is inscribed in the cuboid defined by g ae < 3.8 10 -12 , g ae g eff an < 4.8 10 -18 , and g ae g a < 7.7 10 -22 GeV -1 , and excludes either g ae 0 or g ae g a g ae g eff an 0. The neutrino magnetic moment signal is similarly favored over background at 3.2, and a confidence interval of 1.4; 2.9 10 -11 B (90% C.L.) is reported. Both results are in strong tension with stellar constraints. The excess can also be explained by decays of tritium at 3.2 significance with a corresponding tritium concentration in xenon of 6.2 AE 2.0 10 -25 mol=mol. Such a trace amount can neither be confirmed nor excluded with current knowledge of its production and reduction mechanisms. The significances of the solar axion and neutrino magnetic moment hypotheses are decreased to 2.0 and 0.9, respectively, if an unconstrained tritium component is included in the fitting. With respect to bosonic dark matter, the excess favors a monoenergetic peak at 2.3 AE 0.2 keV (68% C.L.) with a 3.0 global (4.0 local) significance over background. This analysis sets the most restrictive direct constraints to date on pseudoscalar and vector bosonic dark matter for most masses between 1 and 210 keV=c 2 . We also consider the possibility that 37 Ar may be present in the detector, yielding a 2.82 keV peak from electron capture. Contrary to tritium, the 37 Ar concentration can be tightly constrained and is found to be negligible.